D2a TD5 loses power at WOT on hills [Archive] - Australian Land Rover Owners

twr7cx

20th March 2011, 05:45 PM

I have recently noticed that my 2003 Land Rover Discovery 2a (refresh) HSE TD5 automatic tranmission looses power when I'm on a hill going up at WOT (wide open throttle - while I realise that this term doesn't really apply to the diesel engine as no throttle body I'll continue to use it to represent my meaning that I have my foot flat to the floor). The first time I noticed it I was actually cruising on cruise control, and then it happened again today while I was just driving normally.
It's weird, as it doesn't happen straight away, the vehicle will be happily chugging up the hill and then after a while suddenly power will significantly drop right off. e.g. today I was cruising along the highway, hit the hill at 110km/h, made it half way up still in 4th gear and maintaining my speed at WOT, and then suddenly power was significantly reduced and I ended up in 3rd gear struggling up at 60km/h. After the slope the vehicle seems to get all it's power back.
On the way back I found that my not having the accelerator all the way flat (around 3/4ths instead) I don't seem to get this issue occurring. Any ideas?

twr7cx

20th March 2011, 05:49 PM

I just found this: http://www.aulro.com/afvb/technical-chatter/44990-td5-power-loss-problems.html

Seems like I need to check the MAF sensor and turbo's wastegate modulator.

Xtreme

20th March 2011, 07:30 PM

I experienced similar problems recently with 2001 D2 Td5 Auto - also surging if I accellerated hard on the flat.

I cleaned the MAF with the spray can MAF Cleaner but no improvement so bought a new wastegate modulator ($48). Two bolts and three small hoses to replace it in about 10mins and all was fixed. Now goes better than it has for some time.

Apparantly it is becoming pretty common for these to die and some service centres are replacing them during a major service.

Jason789

20th March 2011, 10:13 PM

Hello twr7cx,

What's your head temp/engine temp doing??
Seems like a coincidence.

Cheers,

Jason

twr7cx

20th March 2011, 10:55 PM

Hello twr7cx,

What's your head temp/engine temp doing??
Seems like a coincidence.

Cheers,

Jason

No change. The temperature gauge sits on about half way mark on the gauge and rarely moves much further up or down on the highway.

Panya

21st March 2011, 03:17 AM

twr7cx

21st March 2011, 08:45 AM

strangy

21st March 2011, 10:21 AM

Check air intake temps with a nanocom whilst you are doing it. Turbo on full chat heats the air it can get to a point where performance is automatically degraded. If that is it it may be your intercooler. Do you notice it more when running a/c? condenser sits in front of intercooler and heats up all the air passing through that and radiator...

While warmer air does reduce performance,the loss of performance mentioned would unlikely be related to this, engine temp would be through the roof if performance loss described was through heat.
Coolant and oil levels would also be indicating significant variances

Check turbo and intercooler hoses and make sure your airfilter is clear.

cheers

twr7cx

21st March 2011, 02:05 PM

While warmer air does reduce performance,the loss of performance mentioned would unlikely be related to this, engine temp would be through the roof if performance loss described was through heat.
Coolant and oil levels would also be indicating significant variances

As you have pointed out it is unlikely to be the turbo running hot (unless there is some sort of fuel cut off system in place which acts when this occurs - or something else of similar means). The reason being that the performance doesn't degrade in a linear means, it's just suddenly happens (like a switch being flicked - on/off). It's likely to be something that's either moving/happening due to the hill, or something else that's moving or occurring due to the higher rpm/throttle opening or work load on the engine I imagine.

Check turbo and intercooler hoses and make sure your airfilter is clear.

Will do.

bitdist

21st March 2011, 08:20 PM

I have had this happen when the fuel pump was on the way out.
I changed it and all was alright again

RANDLOVER

21st March 2011, 11:06 PM

twr7cx

22nd March 2011, 02:00 PM

I found this thread which is of interest - http://www.aulro.com/afvb/technical-chatter/34994-turbo-wastegate-modulator-td5.html#post1450413

strangy

22nd March 2011, 02:37 PM

I think you are on the right track. Your problem does seem to be boost or fuel related. You could by pass the modulator with a piece of vacuum hose to exclude this as the fault.

If it isnt the modulator and it isnt hoses delaminating, you only have 2 other options. One is the throttle position switch.
You can attempt to replicate the fault using cruise control, if no fault with the cruise engaged it will be this switch.
If not any of these then it may be fuel pump. Check out the good oil on fuel pumps, turbo and hoses.

Another thought which comes to mind since yours is a 2a.
Is the Cat still fitted after the turbo pipe or has it been removed?
D2a owners have experienced the Cat collapsing and restricting the flow. Some at high revs others at all revs.
Your symptoms seem too rapid in onset for this to be the problem, but worth keeping in the background till sorted.
The Cat is not a legal requirement on this vehicle so can be removed.

Cheers

twr7cx

22nd March 2011, 03:09 PM

I think you are on the right track. Your problem does seem to be boost or fuel related. You could by pass the modulator with a piece of vacuum hose to exclude this as the fault

What is the purpose of the modulator if it can just be by passed? What will happen if it is bypassed, does that mean it should drive up the hills fine indicating that the modulator is the issue?

If it isnt the modulator and it isnt hoses delaminating, you only have 2 other options. One is the throttle position switch.
You can attempt to replicate the fault using cruise control, if no fault with the cruise engaged it will be this switch.

The issue also occurs with cruise control on. The first few times it ever happened was when traveling down the Hume Highway between Canberra and Melbourne on cruise control. So I assume that means that the throttle position switch is not likely to be the issue then.

Another thought which comes to mind since yours is a 2a.
Is the Cat still fitted after the turbo pipe or has it been removed?
D2a owners have experienced the Cat collapsing and restricting the flow. Some at high revs others at all revs.
Your symptoms seem too rapid in onset for this to be the problem, but worth keeping in the background till sorted.
The Cat is not a legal requirement on this vehicle so can be removed.

The cat is no longer there, so that cant be the cause.

strangy

23rd March 2011, 09:41 AM

twr7cx;1450474]What is the purpose of the modulator if it can just be by passed? What will happen if it is bypassed, does that mean it should drive up the hills fine indicating that the modulator is the issue?

The modulator is essentially an ECU activated by pass valve. It will operate to open your turbo wastegate actuator, reducing boost to ensure max boost parameters are not exceeded. If you by pass the modulator you can exceed boost parameters and put the ECU into limp mode. A restart will reinstate normal opeartion. With gentle throttle use, up to full, you will prove the modulator working or not and the worst you will do (for a once off short term test) is put it into limp mode. If you find it is the modulator dont run it hard in the bypassed state until you replace the modulator.

The issue also occurs with cruise control on. The first few times it ever happened was when traveling down the Hume Highway between Canberra and Melbourne on cruise control. So I assume that means that the throttle position switch is not likely to be the issue then.

Yes, This is good news as you now have ruled out the TPS

Is there any smoke when this happens?

Cheers

Tombie

23rd March 2011, 12:00 PM

The modulator is essentially an ECU activated by pass valve. It will operate to open your turbo wastegate actuator, reducing boost to ensure max boost parameters are not exceeded.

If you by pass the modulator you can exceed boost parameters and put the ECU into limp mode.

Tombie> If you bypass the modulator you actually reduce boost by forcing the wastegate actuator to cut in earlier.

Tombie> The Modulator is a bypass, that bleeds boost away from the wastegate allowing the boost to spool up quicker from launch before cutting over and actuating the wastegate.

A restart will reinstate normal opeartion. With gentle throttle use, up to full, you will prove the modulator working or not and the worst you will do (for a once off short term test) is put it into limp mode. If you find it is the modulator dont run it hard in the bypassed state until you replace the modulator.

Tombie> Running it hard will result in the symptoms described by the OP on hills. The boost is falling away reducing power under load.

Yes, This is good news as you now have ruled out the TPS

Is there any smoke when this happens?

Cheers

To check the modulator, take it off and blow through it....
The port going to the turbo wastegate will be bleeding boost if jammed shut. If jammed open the vehicle will overboost and will be noticed by the 'jerkiness' of overboost fuel cut-out.

strangy

23rd March 2011, 02:21 PM

Thanks Tombie refreshed the memory there....apologies twr7cx for misleading info.

twr7cx

23rd March 2011, 10:20 PM

To check the modulator, take it off and blow through it....
The port going to the turbo wastegate will be bleeding boost if jammed shut. If jammed open the vehicle will overboost and will be noticed by the 'jerkiness' of overboost fuel cut-out.

So ideally when removed when I blow through it it should be closed, this would mean that it is fine. If it is open it means that it's buggered.

Tombie

24th March 2011, 12:54 AM

So ideally when removed when I blow through it it should be closed, this would mean that it is fine. If it is open it means that it's buggered.

It has 1 inlet at bottom
1 outlet top. 1 outlet to the side.

Following the hoses will tell you which is bypass and which is wastegate.

I can't recall right now which is which.

When in non actuated mode air should flow through the bypass port.

LOVEMYRANGIE

24th March 2011, 01:37 AM

It has 1 inlet at bottom
1 outlet top. 1 outlet to the side.

Following the hoses will tell you which is bypass and which is wastegate.

I can't recall right now which is which.

When in non actuated mode air should flow through the bypass port.

When not actuated, bottom port should be blocked with flow from side to top port.

Bottom pipe to turbo pressure
Side pipe to actuator
Top pipe to turbo inlet pipe.

You can't test it as its pulse modulated but if you can blow thru any other combinations when it's unplugged, it's stuffed.
Not expensive to replace and can be picked up for around $40.

Part number PMK100130

Cheers
Andrew

Sent from my backyard TeePee using smoke signals.

Tombie

24th March 2011, 04:20 PM

Thanks Andrew

Its been a while since I removed one to check...

twr7cx

26th March 2011, 03:39 PM

When not actuated, bottom port should be blocked with flow from side to top port.

Bottom pipe to turbo pressure
Side pipe to actuator
Top pipe to turbo inlet pipe.

You can't test it as its pulse modulated but if you can blow thru any other combinations when it's unplugged, it's stuffed.
Not expensive to replace and can be picked up for around $40.

Part number PMK100130

Cheers
Andrew

Sent from my backyard TeePee using smoke signals.

Well, that's interesting as mine is the opposite - it is currently removed off the vehicle and I can blow through the bottom port to the side port. The top port is blocked!

Bottom pipe to turbo pressure
Side pipe to actuator
Top pipe to turbo inlet pipe.

With it disconnected I can blow through it from side pipe (actuator) to bottom pipe (turbo pressure) and the reverse.
However, the top pipe (turbo inlet pipe) is blocked and cannot be blown through.

http://img94.imageshack.us/img94/9642/img0514m.png (http://img94.imageshack.us/i/img0514m.png/)

Uploaded with ImageShack.us (http://imageshack.us)

twr7cx

26th March 2011, 03:55 PM

the modulator (black thing) is brand new.. the actuator (silver thing on the turbo) has not been changed;)I have been advised by the previous owner that the modulator is actually brand new and has been changed. As you can see from the following pictures it looks new and shinny:

http://img715.imageshack.us/img715/2702/img0514u.jpg (http://img715.imageshack.us/i/img0514u.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)
http://img684.imageshack.us/img684/6775/img0515z.jpg (http://img684.imageshack.us/i/img0515z.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

The actuator looks like it may have also been changed at some point, it has hand writing on it, although as you can see from the quote above by the previous owner obviously not by him:

http://img847.imageshack.us/img847/192/img0516w.jpg (http://img847.imageshack.us/i/img0516w.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

I have removed the actuator and using some compressed air blown into it, it moves which indicates to me that it's probably functioning alright.

it sounds like its going into over boost, the modulator has never been replaced. ide check how much boost its making first and then adjust the mod back a touch so its not making too much boost, or buy a boost box from BAS in the uk.
there was a thread on aulro about a modified MAF bypass hose, its to allow air past the maf so it wont go into a fault setting. this could be an issue due to the mods done and the new head work?The other thought by the previous owner above. I intend to do some further reading on these options.

LOVEMYRANGIE

26th March 2011, 04:19 PM

The writing on the wastegate actuator is the pressure setting in bar ie 1.309bar is 19psi measured at the turbo. Actual manifold pressure would be like 16-17psi.
If you have a very good pressure reg on your compressor, turn it all the way to 0 connect a hose to the nozzle and connect to actuator and very slowly wind up the pressure on compressor reg until
You get close to 1.1 bar.
Put your finger on the actuator arm and slowly tweak it until the reg hits 1.3 and you should feel it move.
I reset mine to 1.45 bar by shortening the rod which now gives me 20psi at the manifold.

The thing is when driving these is that foot to the floor really won't achieve much particularly in an auto and also due to the fact being diesel, it only has a certain torque range so it may well be a need to modify your pedal habit. Having come from 20 years of various high power petrol turbos and lots of V8's, I really had to modify how I use my right foot.

In an auto much over 3500rpm will start to slip the convertor and grunt is lost.

Cheers

Ansrww

Sent from my backyard TeePee using smoke signals.

twr7cx

26th March 2011, 06:34 PM

I did some playing and testing with the modulator this afternoon. When it is connected to a 12v source, the top (turbo inlet) and side ports (actuator) are connected and air is able to freely flow from one to the other.
With no voltage on it, as stated earlier, side pipe (actuator) to bottom pipe (turbo pressure) are connected.
When the ignition is on, the modulator receives 12v.

I then drove the vehicle with the wiring loom for the modulator disconnected - this is basically in effect bypassing the modulator, the car performed as per usual, with no noticeable loss in power.

I believe therefore that my modulator is functioning correctly and that my issue lies elsewhere.

A new symptom appeared yesterday and reoccured today.
Basically yesterday comming up a hill in a 100km/h zone from stand still start at the base, the car performed well and pulled hard, but in 2nd gear, the engine rev to approximately 4,400rpm, and then cut in and out - like brooom, cut and nothing for a second, brooom, cut and nothing for a second, repeat (my father was in the car with me, he thought I was actually taking my foot on and off the accelerator and being an idiot). This is very similair to what happens on other cars when they hit the rev limiter - i.e. a fuel cut.
Today this occured again, however, this time I think it happened in 3rd gear (may have been second however, as I wasn't concentrating too hard or counting) and happened this time at around 3,900rpm. I believe 3,900rpm is too low to be the red line and so don't think this was the rev cut out. This also occured on a hill.
This is making me wonder more about fuel issue with the vehicle. The fuel filter is reasonably new, despite some off road driving it is still clean and in good condition, but I intend to replace it now anyhow.

Any other ideas?

3-Gees

26th March 2011, 10:01 PM

twr7cx

26th March 2011, 10:35 PM

Max torque is at 1950 rpm and as Lovemyrangie said,reving the ring -gear out of it is a waste of time and money!,anything over 3000rpm is overdoing it my opinion,let alone 4000:eek:,mine rarely sees 2800rpm,but Im an old truckie used to changing gears at 1200-1500!,let the donk work like a diesel and you'll be much happier:)(or buy a sports car:D)
Cheers Gregg;)

Yeah mate, that is great advice to apply when driving the vehicle, but at the moment the vehicle is having issues, so reving it the full way up is part of the testing process to try to work out where the issue is coming from. Regardless of where the engine makes it's power, if it can't rev all the way up and is doing funny stuff in the higher revs then it's likely an indicator of an issue.
I appreciate the comments on how to drive my rig normally, but at the moment while it's bumming out when being normally driving on the hills it doesn't quiet apply...
Maximum power of the TD5 as fitted to a 2003 Land Rover Discovery HSE TD5 is 101kw at 4,200rpm. Clearly there is an issue then if my engine is not willing to rev up to this point.
It is also automatic, so the flash point on the automatic transmission when taking off is around 2,200rpm and it should change the gears at the points that the Land Rover developers deemed to be optimum (debatable).
I have a medium rigid truck licence. I have driven a variety of diesel powered vehicles from passenger cars to MR trucks. And this Disco engine is not happy and not behaving itself on the hills, it's not my driving that's causing that, it's a fault somewhere in the engine that I intend to rectify.

biggin

27th March 2011, 11:03 AM

twr7cx

27th March 2011, 12:36 PM

I have been following this thread with some interest, as I had similar problems with my V8 when I first got it.
It turned out that the plastic air intake duct, after the MAF, had slid off the manifold. This was virtually unnoticeable until I brushed my elbow across it, and it moved. Once placed back on and clip tightened, all was good.
My point is that I would not be too quick to discount a problem with the MAF/air intake, even if you have replaced it.

I have checked all the post turbo piping and they are all good. The joiners are fairly new silicone units (which are better than the factory rubber ones).
The preturbo pipe (from MAF/airbox to turbo inlet) I had off yesterday and checked and refitted.
The MAF I still need to check. I probably need to organise access to a testbook/nanocom/doovlacydevicethingo to do so though.

The other thing that springs to mind is the fuel pump.

Agreed. It is certainly something that I need to check.

mturri

3rd April 2011, 06:37 AM

Check your fuel pressures.

Raw fuel pump pressure (upstream of fuel pressure regulator) should be 6 to 7 bar.

Regulated fuel pressure (downstream of fuel pressure regulator and engine, just before entering fuel cooler) should be 4 bars steady when idling, down to 3.5-3.6 bar at full boost. Never out if this range.

Fuel pump and fuel pressure regulator usually go hand in hand, if one fails expect the other one to follow.

Hope this helps

Matt

Sharkee

3rd April 2011, 09:42 PM

Sounds like it's possibly fuel starvation could be dirty fuel filter or weak fuel pump. You should be able to hear the pump run when turning the ignition on and after a few seconds it should cut off if it keeps running may be a sign of starving.
Gday although I havent checked for how long as I didnt think it was an issue but I think mine runs for more than a few seconds so does that mean I might have a partial blockage?

RANDLOVER

6th April 2011, 05:16 AM

I wouldn't worry about it, even it it runs for 30 secs, if it doesn't cut out it is not reaching full pressure cut-out or I assume the pressure sender/regulator must be faulty.

justinc

8th April 2011, 06:16 PM

twr7cx

9th April 2011, 02:44 PM

If the vehicle has travelled more than 100K, then suspect the fuel pump. The symptoms you are experiencing are quite common when facing a low output fuel pump. Pressure is a function of volume and vice a versa, the engine will run quite well at half pump output even, on the flat, but ask for more supply when climbing hills or overtaking and that will be a certain result.

I have seen many last to 200K, but most half way between IME

Thanks Justin.
The vehicle has almost 180,000km on it now. I receipts for the work carried out on it for most of it's previous life and will check them later out of interest to see if the fuel pump has ever previously been changed.
I guess that there is only two ways to confirm that it is fact the fuel pump:
Connect a fuel pressure gauge in line and drive the vehicle monitoring the fuel pressures - I assume the vehicle would have to be driven in order to simulate the issue so that the fuel pressure could be monitored while it is occurring.
Remove and replace and if the problem goes away, it was the pump.

I just had a look at it seems that a new pump can be purchased from the UK for under $200.00 AUD delivered, which in my books is reasonable (it's not much more than a Falcon fuel pump retails for here). So the replace test method might be easier than trying to hook up a pressure gauge in line.

twr7cx

9th April 2011, 02:47 PM

Fuel pump and fuel pressure regulator usually go hand in hand, if one fails expect the other one to follow.

What is the symptom of a failed fuel pressure regulator? Does it usually cause too much fuel pressure or not enough or does it vary? I'm wondering if there is any means to identify whether the cause is the fuel pressure regulator or fuel pump?

I have actually just replaced the flexible fuel line that runs underneath the inlet manifold from the front of the head to the fuel pressure regulator as this sprung a leak on me where the rubber hose is crimped to the metal line.

Regulated fuel pressure (downstream of fuel pressure regulator and engine, just before entering fuel cooler) should be 4 bars steady when idling, down to 3.5-3.6 bar at full boost. Never out if this range.

What is the purpose of testing this? Surely downstream of the engine makes no difference as this is the excess fuel after the engine has taken and used that which it required? Isn't this just excess fuel that just runs back into the fuel tank to go around the cycle again?
I understand testing the fuel pressure from between the fuel pump and the engine as this is the fuel that feeds the engine.

slug_burner

9th April 2011, 09:02 PM

What is the symptom of a failed fuel pressure regulator? Does it usually cause too much fuel pressure or not enough or does it vary? I'm wondering if there is any means to identify whether the cause is the fuel pressure regulator or fuel pump?

I have actually just replaced the flexible fuel line that runs underneath the inlet manifold from the front of the head to the fuel pressure regulator as this sprung a leak on me where the rubber hose is crimped to the metal line.

What is the purpose of testing this? Surely downstream of the engine makes no difference as this is the excess fuel after the engine has taken and used that which it required? Isn't this just excess fuel that just runs back into the fuel tank to go around the cycle again?
I understand testing the fuel pressure from between the fuel pump and the engine as this is the fuel that feeds the engine.

some fuel should go back, if not enough then indicates that not enough getting to engine from the delivery side of the pump

mturri

10th April 2011, 06:03 AM

Fuel pressure regulators can fail in a number of ways, one of which being them not steadily holding the required pressure (4 bar) but less, and less pressure means less volume so the engine starves (especially in full boost conditions as it appears to be your case).

As for engine starving, it can be due to a failing FPR or fuel pump (or why not both...). The way to identify this is to measure each pressure individually, idling at first, then if not conclusive at incremental loads.

Here's a schematic of the fuel delivery system on the Td5:
https://www.aulro.com/afvb/images/imported/2017/07/725.jpg

High pressure or "raw fuel pump pressure" line marked in red, "system" pressure lines in blue.

Fuel pump sends diesel at 6-7 bar which enters the FPR, gets regulated to 4 bar and exits the FPR from its backside directly into the fuel rail. Part of the diesel is taken by the injectors and the rest returns to the FPR (internally in EU2 engines, and externally in the later EU3 ones). From the FPR "spent" diesel is sent to the fuel cooler and then back to the filter housing.

This is the fuel pressure regulator assembly:
https://www.aulro.com/afvb/images/imported/2011/04/941.jpg

Fuel pump pressure can be measured by either removing the temperature sensor and screwing in (or getting the right "T" adapter) or by disconnecting the line entering the FPR marked (4) in the above schematic and inserting an in-line device.

Also from the above schematics it can be deduced that regulated fuel pressure can only be tapped into once diesel leaves the FPR, in practice by disconnecting the hose going into the fuel cooler. The Td5 fuel sender pumps about 180 lts/hr thence even on a fully loaded engine the injectors only take a minimum volume of diesel therefore not reducing pressure significantly.

After years of struggling with Td5 fuelling problems (on both own as well as other peoples) I put together a gadget to this effect. Using parts from a failed FPR devised what in essence is an extension fuel hose with a side outlet where an electronic pressure sender was mounted. Built a long enough loom as to reach the cabin and adapted a cheapo suction cup type cell phone holder to which the electrical gauge was fixed to. The Autometer kit I used was a costly item and yes I could have gone analog (standard mechanical pressure gauge), but I wanted to have the ability to drive the vehicle, eventually flooring it, without the presence of a live diesel hose in the cabin, or say a mechanical gauge hanging from the windscreen wipers. No fancy looks but does indeed help, here's a few pictures:

https://www.aulro.com/afvb/images/imported/2011/04/942.jpg
https://www.aulro.com/afvb/images/imported/2011/04/943.jpg
https://www.aulro.com/afvb/images/imported/2011/04/944.jpg
https://www.aulro.com/afvb/images/imported/2011/04/945.jpg

Having not only used it for diagnosing fuel pump & FPR troubles but also for day to day drives I have come to learn the following:

Raw fuel pump pressure (sender installed upstream of FPR):
- Runs between 6 and 7.5 bar
- Not a steady value, even when idling permanently oscillates in a 0.5-1 bar range
- Decreases slightly as fuel heats up (can be observed when starting from cold)
- Decreases as fuel consumption rises

Regulated fuel pressure (sender installed downstream of FPR and injectors, i.e. upstream or downstream of fuel cooler)
- Runs at 4 bar (58 psi) steady
- Decreases more noticeably when consumption rises (down to 3.5 bar at full boost)

In conclusion:

1- If fuel pump is busted raw pressure will be either too low or all over the place (specially on a fully boosted engine)
2- If FPR is busted regulated pressure will be either too low or waving up and down
3- Both pressures can look good at idle speed but start misbehaving as fuel expenditure increases

Other own conclusions (that could well be wrong):

a- Fuel pump is cooled by diesel within the tank, as fuel level drops fuel pump works hotter, then not recommended to run on an low tank as a habit
b- Fuel pump and FPR work in association, when one malfunctions the other one suffers, then when one goes down the other will soon follow
c- Partially clogged fuel filters do fuel pumps no good (one can sometimes get rid of fuel pump whining by replacing the fuel filter), too bad fuel pressure upstream of the filter cannot be monitored.

...I'm exhausted... hope this helps!

Cheers

Matt

twr7cx

10th April 2011, 01:34 PM

That's an absolutely sweet setup Mturri, but probably far more effort than I intend to go through! I think my fuel pressure test gauge is an ABW low pressure unit for carburetor vehicles.
At $450.00 for a new fuel pump and pressure regulator I'm probably better off just purchasing both and installing them than forking out a couple hundred to setup a gauge to test/monitor them - if I get 100,000kms out of them after replacing then I'll be happy!

jf1056

10th April 2011, 05:40 PM

just a thought, the first outlet hose from the turbo delaminated inside on mine and created power loss under hard acceleration / high boost. Have you checked the inside of this hose? if yours is delaminating causing a bockage in airflow than it could cause significant power loss under load but not under moderate load / boost. Changed my hoses to silican and problem was fixed for me.

twr7cx

10th April 2011, 09:59 PM

twr7cx

14th April 2011, 04:58 PM

I have also found that the fuel economy is not very impressive - currently doing 14.8litres per hundred km's with about 75% of the distance being highway kms.

twr7cx

10th June 2011, 11:46 AM

Yesterday I finally had a day off and chance to get down to Justin Cooper's who connected my ride up to his Rovacom setup. He tested the MAF for me - no problem there. Then he looked at a few other screens and details for me and has pointed me to check the wiring for the turbo wastegate modulator. Big thanks to him for his time and efforts - very much appreciated!

The other big learning for the day is that this car is a known problem vehicle on here, it's previous owner also had these problems:
http://www.aulro.com/afvb/technical-chatter/115576-my-d2a-td5-pile-dog-poo.html
http://www.aulro.com/afvb/discovery-2/90218-excessive-fuel-consumption.html
http://www.aulro.com/afvb/discovery-2/96741-excessive-fuel-consumption-rd2.html

I guess that serves me right for buying from a fellow AULRO member and not fully checking it all out myself. Lesson learnt.

OffTrack

11th June 2011, 07:33 AM

I guess that serves me right for buying from a fellow AULRO member and not fully checking it all out myself. Lesson learnt.

If you are buying from a fellow member it's worth doing an advanced forum search on their username. While you'll get a lot of chit chat in the results there is often enough information about the car to get a feel for any problems the car may have had and the kind of work the car has done.

I was looking at a car advertised by a member and found while the seller had made about 3 posts the previous owner had also been a member. The previous owner reported on his vanning trips, and also on the mods he'd done to the car. It was useful when looking at the D2 to have some background on what had been done.

Unfortunately it seems the car had lead a pretty hard life and had a raft of issues when inspected, so I didn't end up buying.

cheers
Paul

twr7cx

13th June 2011, 07:18 PM

Today I was checking the wiring for the turbo wastegate modulator as per Justin Cooper's recommendations. Sadly no simple issue with the wiring. Maybe an internal earthing fault in the ECU?

I did find this though, which seems strange:

https://www.aulro.com/afvb/ (http://imageshack.us/photo/my-images/59/cimg0075vo.jpg/)
https://www.aulro.com/afvb/ (http://imageshack.us/photo/my-images/20/cimg0074ef.jpg/)

It's a black sheethed wire for about 25mm out of the ECU plug, then the sheeth is gone. No mention in the RAVE Manual of what this wire is for. I would assume it's an earth wire though.

Also confirmed that the engine wiring loom is not the original wiring loom. It had been replaced as the sticker gives a date of 16 May 2007:

https://www.aulro.com/afvb/ (http://imageshack.us/photo/my-images/191/cimg0076p.jpg/)
https://www.aulro.com/afvb/ (http://imageshack.us/photo/my-images/695/cimg0078c.jpg/)

The ECU code:

https://www.aulro.com/afvb/ (http://imageshack.us/photo/my-images/851/cimg0079x.jpg/)

Have ordered a Nanocom and going to install a boost pressure gauge and do some monitoring and testing on that end.
Wondering if one of the Boost Boxes might fix it?

strangy

13th June 2011, 08:55 PM

Re fuel economy, I notice from some of the links you posted, the head has been off and machined. It seems everthing that could cause these problems has been changed or checked at one time or another.

It may be worth checking the timing for accuracy. Not just by eye but with correct locking/ location tools (factory or custom makes no difference) This timing is critical and near enough is not good enough.

cheers

OffTrack

14th June 2011, 07:20 AM

The pink/black wire is C0158-13 and the grey/blue is C0158-36 shown on page 43 of the wiring diagram section of RAVE. The black wire will be ground connected, and is most likely a shield to prevent interference.

twr7cx

15th July 2011, 11:24 AM

Thanks to all that contributed ideas and thoughts to this problem I was having.

The problem has been solved by the fitting of a Turbo Booster Box and uprated MAF from TD5 Alive/Alive Tuning. I don't know which, or if both, devices was the solution, but all I care about is that the vehicle is good to go now!

Thanks again.

DiscoJakes

19th July 2011, 05:55 AM

Glad you're sorted - just curious

Does the booster box wire into the MAP sensor or wastegate modulator wiring ?

If it is the modulator wiring, surely you could have made it fender spec ...

Redback

19th July 2011, 09:50 AM

Glad you're sorted - just curious

Does the booster box wire into the MAP sensor or wastegate modulator wiring ?

If it is the modulator wiring, surely you could have made it fender spec ...

Wired into the ECU plug.

Baz.

discowhite

19th July 2011, 05:16 PM

i offered you every chance to take the car to what ever mechanic you wanted to look the car over before you bought it.
i also answered every one of your questions honestly.
and the fact of the matter with this car...nobody knew what was wrong with it... i could drive it and it could be good or bad others would drive it and it was good. you drove it and didnt have any problems.
a well known LR mechanic had looked at the car and said that there was nothing wrong with it and that everything that ide done/replaced on it was exactly the same thing he would have done.

eitherway glad its sorted now..

cheers phil

Yesterday I finally had a day off and chance to get down to Justin Cooper's who connected my ride up to his Rovacom setup. He tested the MAF for me - no problem there. Then he looked at a few other screens and details for me and has pointed me to check the wiring for the turbo wastegate modulator. Big thanks to him for his time and efforts - very much appreciated!

The other big learning for the day is that this car is a known problem vehicle on here, it's previous owner also had these problems:
http://www.aulro.com/afvb/technical-chatter/115576-my-d2a-td5-pile-dog-poo.html
http://www.aulro.com/afvb/discovery-2/90218-excessive-fuel-consumption.html
http://www.aulro.com/afvb/discovery-2/96741-excessive-fuel-consumption-rd2.html

I guess that serves me right for buying from a fellow AULRO member and not fully checking it all out myself. Lesson learnt.

discowhite

19th July 2011, 05:19 PM

Today I was checking the wiring for the turbo wastegate modulator as per Justin Cooper's recommendations. Sadly no simple issue with the wiring. Maybe an internal earthing fault in the ECU?

I did find this though, which seems strange:

http://img59.imageshack.us/img59/3500/cimg0075vo.th.jpg (http://imageshack.us/photo/my-images/59/cimg0075vo.jpg/)
http://img20.imageshack.us/img20/4936/cimg0074ef.th.jpg (http://imageshack.us/photo/my-images/20/cimg0074ef.jpg/)

It's a black sheethed wire for about 25mm out of the ECU plug, then the sheeth is gone. No mention in the RAVE Manual of what this wire is for. I would assume it's an earth wire though.

Also confirmed that the engine wiring loom is not the original wiring loom. It had been replaced as the sticker gives a date of 16 May 2007:

http://img191.imageshack.us/img191/6479/cimg0076p.th.jpg (http://imageshack.us/photo/my-images/191/cimg0076p.jpg/)
http://img695.imageshack.us/img695/8849/cimg0078c.th.jpg (http://imageshack.us/photo/my-images/695/cimg0078c.jpg/)

The ECU code:

http://img851.imageshack.us/img851/3945/cimg0079x.th.jpg (http://imageshack.us/photo/my-images/851/cimg0079x.jpg/)

Have ordered a Nanocom and going to install a boost pressure gauge and do some monitoring and testing on that end.
Wondering if one of the Boost Boxes might fix it?

have a look at the pile of paper work you got, pretty sure that this was replaced by trivetts for the owner before me.

twr7cx

21st July 2011, 06:43 PM

i offered you every chance to take the car to what ever mechanic you wanted to look the car over before you bought it.
i also answered every one of your questions honestly.
and the fact of the matter with this car...nobody knew what was wrong with it... i could drive it and it could be good or bad others would drive it and it was good. you drove it and didnt have any problems.
a well known LR mechanic had looked at the car and said that there was nothing wrong with it and that everything that ide done/replaced on it was exactly the same thing he would have done.

eitherway glad its sorted now..

cheers phil

Phil, I haven't blamed you. If I had, or had a problem with you personally, you would know about it as I would have spoken directly to you. My statement was that it was MY (me, not you) bad for not reading about the vehicles history on here. You are correct that you were not required to disclose the fuel issue to me - at the end of the day you were a seller trying to get the best price you could and I was a buyer that as you pointed out had the opportunity to test it out and get it checked out (although realistically unless I test drove it for 500kms I still wouldn't have known about the bad fuel economy nor would a mechanic have been likely to identify it).

Either way, I think we can leave it there as it's better now. The power issue is 110% fixed and it's pulling harder now than it was when I first got it. The fuel economy has improved too, but is still not were it should be.

twr7cx

21st July 2011, 06:46 PM

Does the booster box wire into the MAP sensor or wastegate modulator wiring ?

Taps into the wiring loom plug that plugs into the ECU. I believe the wire is the wire from the MAP sensor.

DiscoJakes

25th July 2011, 04:44 PM

Thanks for that, I've pretty much done the same with a voltage regulator to "fool"the ECU by only supplying 4.5Volts to the MAP sensor. Works, but you need a Madman/boost gauge inside to monitor and alarm.

Harold

31st December 2015, 10:09 PM

A thank you to mturri for the inspiration to make something similar to his design for checking fuel pressure problems.
My pressure testing device is made from VDO components. The response from these is dampened but their accuracy seems good.
How I think the Fuel regulating system on the TD5 EU3 engine functions.
The fuel from the High Pressure outlet of the pump is feed through the body of the regulator and into the Metal mesh filter in the head. (No action is performed on the fuel by the regulator at this point). The vast volume of fuel is not used by the injectors and returns to the regulator, this is where the regulator acts on the fuel to regulate the upstream fuel to 4 bar. The fuel then flows to the fuel cooler before returning to the tank. The only pressure in the line downstream of the regulator is the restrictions of the line and whatever happens in the main fuel filter.
I installed my pressure measuring device in the line which runs from the front of the head and returns to the regulator. Without the engine running but with the fuel pump working the pressure was approximately 3 bar. When the engine was started this increased to 4 bar. I cannot explain this, possibly vibration having an effect on the regulator. When driving I did not notice any change from 4 bar, but this may be due to the slow response of my measuring equipment.
I am thinking of making an adapter to measure the inlet fuel pressure at the fuel temperature orifice on the regulator.( the fuel inlet and the temperature sensor share a common gallery) This will give an indication of the resistance offered by the metal mesh filter in the head.
Clean the mesh, observe the pressure upstream of the mesh. As the mesh becomes blocked the pressure at the temperature sensor orifice will increase. Experience will then determine when the mesh needs cleaning.