TD5 - Air In Fuel Lines- Difficult Starting
I am new to this forum.
I have a 2002 TD5 with 155,000 kms. Also a Disco 1 V8 on Gas
My problem is that the TD5, is difficult to start.
I have been looking at many of the threads relating to air in the fuel system.
I have a few questions if any one can point me in the right direction.
I will first list the sequence of events leading up to the issue and then the symptoms to date. The TD5 would normally start first kick, never more than 1 turn and away it would go.
Then one morning I noticed that after a normal start it hesitated for a second just after it started (the engine shuddered like a lack of fuel ). I thought that is odd!
Ok for the next 2 months this hesitation after starting would occur randomly, usually after a night sitting.
Then I put it in for a service (with Land Rover Dealer) and they mentioned that the Fuel Pressure Regulator (FPR) was leaking.
They replaced the FPR and on return my TD5 began to get hard to start ( more than 1 turn of the motor to start and sometimes I had to put foot flat to the floor.
I took it back but they said it was the fuel pump as the dealer checked the pressure and during driving they said it occasionally dropped a little (marginally they said).
Mind you I had just had the fuel pump replaced 5 months earlier. Not convinced I took it to the person who replaced the fuel pump. He said the pump was good but the return pressure was low.
He replaced the fuel air bleed valve in the fuel filter return line and new filter.
It only got worse after that. I decided to have a look. The return line fitting was leaking so I replaced the copper washer and tightened it up, bleed the fuel system of air by turning on pump and pumping the throttle 6 or so times till the orange engine symbol light appeared on the dash and let the pump cycle until the squealing pump ( air bubbles in the line causing the pump to cavitate, I think) quietened down and I couldn’t hear air bubbles circulating through the fuel rail at the front of the car and then listening at the fuel filter until the air bubbles sound disappeared there as well. This took 5 cycles of me turning the ignition to position 2 pumping the throttle 6 times and letting it cycle the pump 4 or 5 times. Once the pump finished cycling I repeated the cycle 5 times. I now thought the issue had been air in the system that needed to be thoroughly bleed.
I thought!!!!! the issue was fixed but over a few days the car became harder to start and the pump got louder and the gurgling and air bubble sound was more pronounced until it was back to being difficult to start ie run the pump for 5 mins, foot to the floor and try and start (not good for the battery or the starter motor).
So here I am, I have had a look at the injectors to see if I could see a leak (my thought was now that the FPR was replaced maybe it was holding more pressure and causing the injectors to leak. I checked the engine oil level for an slight increases none found over a 2 week period. I have ruled the injectors out but may still replace o-rings and seals. I then took the pump out and checked the filter –clean no foreign material present. Put it back.
Have checked all around fuel lines for leaks non found to date.
I have checked the ECU red plug for oil-none. The harness was replaced 6 months ago.
I know air is getting in. I know that the air forms first at the filter end and then the sound migrates to the FPR/fuel rail (head) area.
I also noticed that once the fuel pump stops it sounds like a heap of fuel with air bubbles runs back through the filter. Ie pressure relief through filter.
1. Is the fuel system supposed to hold pressure once the pump is stopped?
2.What type of fitting and where do I need to attach to in the fuel line to measure the Low, High and return lines pressures to determine which line is leaking?
3. Can you buy fittings to attach to the fuel filter lines to measure these?
4. Has any one got some pics on how they set up the pressure gauge to measure these 3 lines?
5. Can you get air sucking into the lines or around the filter without having a fuel leak.
6. Can the fuel line slip on connections suck air in? They rotate easily by hand at the filter housing and FPR. I am surprised that these fitting can hold so much pressure and still able to rotate from side to side. At the connection.
7. Is it worth using soapy water around these fittings?
8. What could have they done when they replaced the FPR to cause this issue?
9. How small a leak could cause this, could it be so small that the fuel evaporates or gets absorbed in dirt before I can see any real signs like staining etc?
10. Could the fuel be leaking into the cylinders from the injectors or would this still show up in the sump oil?
I am a little frustrated and need some direction please.
Sorry this is so “long winded!” Just though if I give as much detail as possible someone could help.
I don't know much about diesels, but have you checked the airflow meter (MAF).
I understand that a disconnected MAF runs better than a faulty one.
Just a thought.
I have had MAF problems myself, and they cause all sorts of issues, especially symptoms that look like fuel problems.
Anyway, the big guns will be along shortly.
O yeh, and welcome.
2002 D2 V8 Auto SLS+2" ACE CDL Truetrac(F) Detroit(R) Nanocom
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DiscoLemonSucker (29th April 2011)
I know the voices in my head aren't real......but sometimes their ideas are absolutely awesome!
I would remove the injectors and check carefully for leaking copper washers at the base of the injectors. They can get a gas (Compression gasses) track across the base of the injector between the injector body and the washer. This can cause air to 'congregate' in the fuel gallery overnight or when sitting for a while.
I have seen one so bad that after a long hill climb the fuel pump started to scream and the vehicle slowed, then stopped. After a roadside bleeding session I could drive it back down to work.
Not that unusual actually, even for 2003 models.
I'll back JC suggestion the easiest way to test for this is to get the vehicle parked on a lean to the left and fill the filler to the absolute brim of the tank filler, complete the purging sequence then run the engine through a series of starts and stops after topping up the tank after the purge sequence...
IF you have injector blow by you'll get bubbles in the filler neck and fuel displacement out of the neck if its bad enough.
It's nearly impossable for the fuel lines on a TD5 to suck air in as they are positive pressure at all stages after the tank which has the pump in it. If the problem goes away when you have the tank full then you are getting areation of the fuel through the pump itself. If thats the case the problem will start at anything much below 2/3 of a tank be livable down to about 1/4 of a tank and may get to be impossable to start below 1/8th of a tank.
"In a Landrover the other vehicle is your crumple zone."
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Thanks for the advice.
I did remov the filte earlier today and checked the seal ans also had a look at the air bleed valve on the return from filter. Both looked ok. I will try the " Left lean full tank fill injector air bubble test" tommorrow.
1. If i am getting areation from the pump (genuin LR part) obviously it needs to be replaced but what would have caused it to fail only after 5 months and 10,000 kms. It just seemed too coincidental with the FPR replacement.
2. Can any one point me to a tut on replacing injector seals.
1- The fuel system will bleed pressure back to the fuel tank once the pump is stopped.
2- The easiest thing to do is to fabricate a quick connect type device that can be connected at different points to assess both fuel pump and fuel pressure regulator pressure. This post describes my effort: http://www.aulro.com/afvb/discovery-2/127845-device-measure-td5-fuel-pressure.html (this is not recent but just posted in AULRO for everyone’s benefit)
3- See #2
4- See #2
5- Very unlikely, fuel lines are pressurized and will leak not suck in(pressure trying to escape).
6- Same as #5, have owned (5) Td5s throughout the last 11 years and am yet to see one of the slip type fuel connectors leaking.
7- Not IMHO
8- Hard to say, your problem appears to be coming from leaking copper washers at the base of the injectors (combustion gas getting into fuel rail)
9- Fuel sender pumps 6-7 bar, FPR brings down to 4 bar, any significant leaks in the system WILL be noticed.
10- Cylinder compression is about 20-24 bar, fuel rail (diesel surrounding injectors) is 4 bar, if copper washers leak you’ll get combustion gas into the fuel rail and not the other way around. Diesel in oil is generally caused by leaky o-rings in the upper part of the injectors (fuel rail 4 bar vs almost zero pressure within crankcase).
this is an interesting read . i had posted something similar a few months back when my 2000 my td5 began to do the same , start alright then within seconds "run out of fuel". the first 6 times . i recorded in the trip diary . it did this the tank was about 1/2 full. the easiest way to reprime was to put fuel in , i always had a jerry can available. as well it didnt seem to matter if the car was flat or on an angle ? the interesting thing was , when returned to Geraldton for a service nothing was found o be faulty. All was fine for a few tanks then the fun began again here in Perth , now when sitting at about a quarter tank. trying the priming sequence failed to get a result unless i first immobilized then retried the sequence. but once filled up or if i continue to drive past the half tank all is fine. the fuel pump has been replace 3 time since kununarra as the engine was rebuilt due to a fuel line issue there. it was thought at the second replacement this was an issue of concern and the third replacement due to it possibly being a "dud". i am of the opinion it is electrical or computer related as no physical problem has been found and as the two mechanics say that they have never heard or this before. good luck and hope all works out.
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DiscoLemonSucker (2nd May 2011)
Thanks for the answers. I needed to hear it from someone else to confirm some of my thoughts. After reading some of the other threads on these type of issues I feel your answers have filled in many of the gaps they didn't answer in full. ie Q 10's answer etc.
My original pump failed at around the 180XXXkm mark, I fitted a brand new genuine pump early 2008 - within weeks it started screaming again, and to my detriment I put up with it and didn't replace it under warranty - though I noted it with my service guys.
So unless Rovacraft are feeling expecially generous - I'm up for another $700.
Here in the west the summer weather really hammers it home - as Dave says, below 1/8th of a tank...it can be a PITA to start.
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