Cold idle RPM gems V8 [Archive] - Australian Land Rover Owners

prelude

8th October 2018, 06:54 PM

bee utey, I have not touched the idle speed but thanks for the tip ;) I did take the throttle body apart to replace the o-ring since it was sucking in air there but I did not touch any of the adjustments... Might be worth a look when I get the IACV replaced.

Speaking of which, I tried to take that thing apart and boy what was LR thinking. M4 bolts with locktite?! Ofcourse mine had been in there for 20 odd years and the first gently twist snapped the head clean of. If I leave al the nsfw words out, I did not say a lot...

Anyway! After a couple of hours trying to get the snapped of bolt out, rethreading both holes, new bolts etc. I could finally get to work on the iacv. It was dirty so I took a wirebrush drillbit to it and... I unscrewed the centre pin. Ok I thought, good thing since I can get to cleaning the bloody thing a lot better. Got it nice and clean and smooth and removed some of the old hard grease and replaced with something fresh. I got the pin to move though with quite some resistance. Tried taking it apart again but to no avail. Pushing it further in was really hard too and since I did not want to break the bloody thing I just tested it out on the car. The idle speed was up instantly to almost 2krpm. I gave the computer and IACV some time to settle down but after a few minutes I could see the computer (faultmate) reduce the amount of steps to about 120 but nowhere near the 20 I've seen here and there. I doubted the IACV was doing it's job so I took it out once again and tried more force to get the pin to move. Something said snap and after that there as movement in the pin though I doubt it is still functioning as intended :(

Seeing as a replacement is around $25 down here I simply ordered a new one and will pick this back up once that comes in.

Cheers,
-P

TheTree

9th October 2018, 08:05 AM

Hi mate

Sadly I think your IVAC is toast, it says in RAVE not to push or pull the center shaft while cleaning it [bigsad]

Steve

prelude

18th October 2018, 07:16 PM

So I replaced the IACV. It turns out that it was an aftermarket unit that is also used on a jeep grand cherokee according to the seller. This means that the plug is on a bit of a weird angle for our application and the wiring harness is barely long enough. I am considering replacing it with one that has the plug in the right position but for now at least my car idles below 2krpm :)

This is where the good news stops though. I could not get the car to idle normally whatever I tried and how much time I have the engine to heat up, it was stuck at around 2krpm. In a last ditch attempt (seeing as the old one was most likely broken to begin with) I reset all the adaptive values and et presto, the idle rpm dropped to 750-ish immediatly. hurray! or so I thought.

The engine idles a bit rough but it always has, in my opinion this is due to the piper 285 cam. However when I try to move the car the idle is disastrously low, stalling the vehicle. Most suggestions around on the web state that it is the IACV but I just replaced it :)

This is what happens:

Car from park in drive, idle picks up well with the added load. I can set of without problem and drive around without problem as long as I do not stop. Once I come to a stop the idle drops to low 200's. The only reason the engine stays on is that a V8 has more power strokes than a four banger :) if I wait for say 10 seconds the idle slowly recuperates and I can set of normally. If, on the other hand, I need to drive in stop and go traffic the engine will stall.

When reversing, I put the car from park in reverse and the idle picks up well again. Releasing my foot from the brake the car will move backwards but by the time the car reaches the speed that is equivalent to idleing backwards the idle drops like a brick to low 200's and often even lower and stalls.

By that same token; making a 3-point turn is impossible; switching quickly between gears (through neutral) does give a fairly normal idle of 500rpm during the short period of time the car is in neutral but when in gear it will drop to the low 200's again and releasing the brake to actually try and move will stall the engine.

I have been playing this game for an hour or so yesterday, intermixed with normal driving and the adaptive value learning system has managed to get the rpm at least stable enough as to not stall the engine every time I come to a stop, but it still drops to far for my taste.

Finally I tried a "cold" start this morning, I left the car out and with an outside temp of 15c we can argue about the "cold" part there but hey ;) The car started fairly normaly but it did not start with a high idle, the kind that keithy described but I hesitated a bit around 800rpm before settling on 900-ish and remaining there for the few minutes I let it run. I had to get to work so I did not connect the faultmate or drive around this time, I was just curious to see what would happen.

All in all this is "workable" but not really what I was looking for. The rave manual (and I have not read every single page but searched on IACV) is not really helpful here, perhaps there is some adjustment procedure I do not know about...

What I have done recently: fixed an air leak, replaced the MAF sensor, fix the PCV and replaced the IACV.

Anyone have any ideas?

Thanks!
-P

Keithy P38

20th October 2018, 12:50 AM

You mention you’ve fixed an air leak. To me it sounds like a massive vacuum leak. Perhaps as far as a stuffed intake manifold gasket.

If you squirt water (gently) over the intake manifold while it’s idling, does it change how the engine runs?

Cheers
Keithy

DavidP38

22nd October 2018, 04:11 PM

what maf sensor did you get and why did you replace it and not just clean it? mine is still running the original LUCAS one and it's fine 320k later, all I do is CRC clean once in a while, with the GEMS I would buy the exact OEM replacement (probably Bosch) or else you'll get nowhere with cheap YumCha ones

the biggest difference in idle and off idle pickup I've noticed was with new plugs

I find that most remanufactured parts these days are absolute crap, special MAF/MAP sensors and finding an OEM replacement is hard, I would take the multimeter out and check the new sensor works as expected

4bee

22nd October 2018, 04:33 PM

Yes the IAC body is very thin & looks undercut at the end of the thread as I found to my cost recently & it snapped off.

I removed the casting & hack sawed it along the thread & then separated it with a small chisel otherwise it would have been impossible to remove without filling the engine up with cuttings etc. Job done.

TheTree

22nd October 2018, 09:43 PM

I tried one of the Jeep IACV and found that it did not seem to work properly so I went for the correct one

Steve

prelude

23rd October 2018, 01:02 AM

Hey guys,

The MAF sensor I should add was swapped, not replaced. Typo in my original post :) It was suspect a while back but the original (cleaned) MAF is back in place. The vacuum leak as far as I can tell is fixed. I tested the system by taking off the MAF sensor, putting a plug into the air intake, connecting an air hose with slightly pressurized air and adding to that a smoke generator. This way any leak in the system shows as smoke escaping, really neat trick! if I say so myself :P

About the IACV, yes, I think I'll order a new one. I usually take what I can get and this one was on fleebay for not too much money and quickly delivered. I'll go find the original product asap.

My plugs are.. 30K old? Not sure how often to replace them but it won't hurt taking them out to check I guess. The car drives beautifully so I would not suspect anything, if it were not for that bloody idle :(

Last weekend I did the JOTA (I work as a volunteer for the scouts 60K's north of here and I am a licensed HAM radio operator) and I took the range with me, including RTT. It drove quite well and once it is warmed up the idle is OK-ish. It still drops a bit to far when coming to a halt going forward, but does not stall.

It still drives like sh*t going backwards or when cold.

Cheers,
-P

4bee

23rd October 2018, 08:06 PM

Oddly enough I have had this crap idle for a few weeks now. No biggy, but just damn annoying.

Tried everything I read or knew about & today I screwed in (tightened) the Throttle cable a smidgin' by rotating the black plastic knurled nut at the end of the Throttle Body at the slotted bracket. This obviously affects the linkage & I was able to lift the idle RPM to about 750, I know, it's a tad fast, but it feels & sounds better & I am quite happy to leave it here. I did have it over 1000 rpm at one stage while fiddlin' but soon screwed it back.

I had a bloke ask me about the movement of the IACV moveable pintle a couple of months ago & this is what I was able to tell him..

Read on Dear Reader...........

According to the Installation Instructions that came with my replacement a few years back, it isn't supposed to physically push in & out but you depress & release the spring from it's slot (pintle end) & rotate the shaft in or out to give you a dimension of 28mm from the gasket mounting surface to the tip of the pintle. NB.Return the spring leg to it's original location when you are finished.
If it is too long, internal damage can occur to the IACV.

Torque when tightening the valve back in is 13ft/lbs. (48 NM) & using a 32mm wrench.

Bugger, how to get rid of Bold type?? No matter. [smilebigeye]

I can send you a copy of said Inst. if I have your E-mail Addy. Perhaps you could PM me?
P.S. There is a Reset Process that may be followed for Buick & Pontiac but as that won't affect you I can't be arsed typing it all.[wink11]

Keithy P38

25th October 2018, 10:23 AM

I have a question regarding the winding the throttle cable. I’m not an expert here, so please excuse if I have this wrong!

The throttle position sensor (in my mind) would now be seeing a higher than 0% throttle position at your new idle speed as a result of this, would I be correct? If that’s the case, that would also effect deceleration fueling, as the ECU would otherwise turn the injectors off during deceleration between X and Y rpm, and as it’s now seeing a position above 0, this wouldn’t happen.

Just food for thought!

Cheers
Keithy

bee utey

25th October 2018, 11:49 AM

4bee

25th October 2018, 11:50 AM

Thanks for that.

You may be correct with all that Keith & Jaden, I don't know, but if it is, it's not evident in any way I can see or feel,. Tried the Base Idle Allen Screw Jaden, made no difference. The fact I am going on the OEM fitted rev counter ( and we all know that is a crap practice, but I don't have access to a better one for this small matter [bighmmm]) so it could have been out for Donkeys years, hopefully in the right direction, which would make SAPOL & the Govt. coffers unhappy. Hhmmmmmm, now having said that.........................:soapbox:

As it happen, 'er indoors has just driven off from a cold start (to go lunching with the girls you see[bigsad]) & the short time she let it idle before moving off, it sounded a lot better & more responsive.

Just having had a new "Big Box Tri-flow" muffler fitted a few weeks back & (imagine an empty 44gallon drum with a couple of pipes hanging out of it & not my choice I hasten to add) made it sound worse then but it sounds ok today for which I suspect was caused by the low rough idle rpm. Now 750, but it could be 600 in reality for all I know, which is good enough for me. Have you ever tried to accurately set the idle on a 3.9. One follows the Manual & procedure & blocks off pipes etc & eventually it still turns out crap. For many years I recall, idle speed was always done by ear not "noo fangled gadgets". Back in the'50 & 60s & probably later, if one owned a half decent Rev Counter one was King & had some street cred.[smilebigeye]

It also could have been because the Throttle cable stretched a bit since '95. & I have returned it to the original setting. I dunno.

Thanks again for your opinion.

A/C lifts the RPM as it supposed to do so it does seem "normal" if normal is a word one can use in relation to Land Rovers.[smilebigeye]

prelude

28th October 2018, 07:13 PM

I have been driving around with the P38 for a couple of days now, I need to since my daily driver is getting a mike sanders treatment. When warm the idle is ALMOST where it should be, only occasionally will the idle drop to the 500's when coming to a halt but most of the time the ECU corrects nearly immediatly. Blipping the throttle also tends to throw the idle of, unless the enginge is really warm. I have monitored the IACV position with my faultmate extreme during driving and I have come to these conclusions:

When warm and cruising (cruise control on) around 100kph for say 15 minutes, the long term, short and current trim are nearly always around 30, 45, 70. As soon as I start engine braking the current value changes, mostly upwards. When however I get around a very low coasting speed (still in gear) it would drop nearly immediatly (the update interval in the faultmate software is not fast enough to display it I asume) to a low-ish value of around 60. Since this cause the engine to idle to low the ECU will, often, adjust immediatly and recover the correct idle RPM.

When warm and in drive, releasing the brake but not touching the accelerator pedal the car will idle around 750 and accelerate up to the point where the gearbox is not slipping but simply idling along. Once I reach that point/speed the ECU instantly drops the current trim to around 60-ish and the idle drops of to around 500-ish. The ecu usually does not recover from that by itself for some reason. Accelerating, braking or switching to neutral all works without stalling the engine. Braking and neutral will eventually see the idle return to around 750 as it should.

It seems that the ECU does learn, up to a certain point, how to deal with the behaviour of the engine and IACV but within a maximum band of parameters.

When cold however, and since autumn has set in down here, with temperatures around or below 10c there is no hope in hell the ECU will do the right thing. I can get the engine started alright, it will idle as it should even when switching into gear or the A/C switching on and off but as soon as I try to manouvre the vehicle around the idle speed it will drop down to 200-rpm and barely plod along or simply stall. I try to give the ECU as much learning time as possible by fooling around moving the car back and forth every time I start the engine when cold, giving the ECU as many learning points as I can possibly give it but them bloody V8's warm up to fast haha or it stall's too often and the ECU does not seem to learn anything at that point.

What I have noticed when looking around my faultmate is that the O2 sensors for bank 1 and 2, that is to say the fueling, is always jumping up and down and are rarely the same. When bank one is around 1 bank two can be around 5 and vv. I am not sure if this is normal behaviour but it might be adding to the confusion for the ECU. When the car is really hot and idling you can actually see the needle of the RPM on the dash jump up and down slightly.

All in all I am at a loss as to how to fix this problem. I've pretty much ruled out all air leaks afaict, we know the iacv to be working and pretty fast as well, the throttlebody is clean and the PCV's are hooked up to an oil catch can and thus are breathing as the should as well. The only thing I can think of is that my piper 285 cam has a bit of a rough idle, possible letting to much O2 through and upsetting the ECU's fueling, which in turn adversely affects the idle. The weird thing is though that when the engine was new a couple of 10's of K's ago it did not have this problem, at least not this bad.

I am open to ANY suggestions as to how to move forward.

Thanks!

-P

DavidP38

28th October 2018, 11:20 PM

What’s the lobe separation on that cam? 108 or lower and you will have massive idle issues, I can explain why but a rough lope at idle makes me think you must be on 108.... too much overlap

prelude

29th October 2018, 06:23 PM

I would be interested to know why that is :) I don't know to much about cam's tbh.

It took some googling but these are the specs for the cam:

type

power band

valve timing

duration

valve lift

full lift ATDC/BTDC

285

2000-6500

44-72 / 74-44

296 deg.

0.450"

104 deg.

I grabbed this from the RPI site, piper themselves do not seem to have this data online.

The funny thing is, it has worked reasonably well for about a year without too much hassle, sure the rough idle was always there but the ECU at least kept the engine running :) This morning it was a bit of a challenge once again to keep her running...

Cheers,
-P

edited because of those bloody table-paste-fails.

DavidP38

31st October 2018, 06:13 PM

That dont state the LSA but if it has a decent amount of overlap most EFI systems don’t know how to cope

Essentially overlap is when the exhaust and intake valve overlap and both are open

prelude

7th November 2018, 08:31 PM

A final update (I think :P)

If I understand http://www.pipercams.co.uk/Technical-Advice/ this link correctly I need to add 44+44 and I get 88 degrees of overlap? Don't know if that makes sense...

In any case, I have been using the car for another week and the idle is slowly creeping up into useable territory. I tried an old honda trick, which I'm fairly certain does not work the same on our P38's but it has had some positive result so I'll share it here: I disconnected the battery for about 10 minutes (when cold) and then turned on the ignition, manually filled the air tank to the brim (making use of an external power supply) made sure the brake booster did it's thing, turned off the AC and any other electrical users and then started the engine. I let it run for 10 minutes or so without doing anything and with no (or the smallest amount possible) electrical users or aircon.

The end result is that the car can idle fairly normally when cold, the only bothersome behaviour that remains is the creeping forward idle. When I lift my foot of the brake the car starts creeping forward and when it reaches it designated idle speed the idle drops to around 200 rpm. The engine no longer stalls but it idles along very very slowly. The ECU does recover from this point within a few seconds, the car picks up speed again and bang the idle drops down to around 200.

Like I said; I can live with this but I hope it will over time correct even further. Changing the cam is not my first choice but it does indeed seem that the gains I got from this setup have a few downsides as well, the most bothersome beeing the MOT beeing barely met.

Cheers!
-P

DavidP38

8th November 2018, 07:40 PM

The problem I believe is that the ecu can’t adapt to the cam, previously it was ok because it had some adaptive values already from the OE cam

OE cams have an LSA if 112 for a smooth idle with 110 on the newer engine management systems with drive by wire. 108 LSA is what I would call a cammed engine with a good throb and rough idle

prelude

10th November 2018, 09:06 PM

David, would changing out the EFI to a megasquirt or eq. which can be completely tuned by hand make any difference? It's been on my wishlist for some time so maybe the time has come to deal with that :)

I did find the CAM on the piper website, it has different value's but it at least seems to contain an LSA figure:

Camshafts Car (https://www.pipercams.co.uk/Camshafts-Car/Make-Rover/Engine-ROVER-V8-4.0-4.6-Engines-with-no-distributor-short-nose-type-camshaft/)

if I read that correctly the LSA is 110. should still kinda work, right? ;)

Thanks!
-P

DavidP38

13th November 2018, 01:21 PM

110 LSA is very very mild, should idle close to stock with a very very slight lope

I'm actually thinking of looking into a megasquirt, mainly to get around the ****ty GEM coils and sensors and use modern LS coils and modern sensors, either that or a really really cheap entry level haltec in wasted spark (only need the 4cyl model as I don't care for individual injection, just fire all the banks like stock)

I think on the Gems if you go with LS coils, LS maf, NTK O2 sensors stock water, generic air temp and bosch injectors you would get much better everything and in my case remove the last obstacle from believing I can take this thing anywhere! already have coils, all i need now is to remove the GEMS and swap sensors over

Keithy P38

13th November 2018, 09:11 PM

Why not just put an LS motor in?

prelude

14th November 2018, 12:50 AM

In my case: an LS is not common down here and I could get a new crate engine but I "just" (30k ago) put in this completely rebuild engine which already cost me a bloody fortune :) I would like to get rid of the GEMS ECU but I know the BECM is a bit of a difficult thing to deal with. I'm not sure just ripping out the GEMS ECU will play nicely.

Then again, getting rid of that bloody BECM is even better. I can probably replace all the functionality of that thing with an arduino or similar. It's just a CPU with a bunch of inputs and outputs. That would also go a long way in waterproofing the beast. The only major concern is that I was not planning on replacing the stock ABS/TCS and EAS cpu's. Not sure how they will react or even work without the BECM. Though EAS could be considered for redevelopment into an arduino or whatever, I'd rather not touch the ABS. Though, removing that all together could be an option...

I'll make a vid of my engine idling when I get the chance so you guys can tell me what's what maybe :)

Cheers,
-P

Keithy P38

14th November 2018, 01:23 AM

Sounds pretty complicated haha! My comment above was to David, my apologies mate!

prelude

15th November 2018, 08:49 PM

no worries :) I guess I'm just a bit enthusiastic... It does sound complicated though!

-P

DavidP38

16th November 2018, 03:31 AM

LS would cost too much, new bell housing etc and would probably retire the zf box pretty quick. The biggest reason to go aftermarket ecu and sensors is because finding good parts for the p38 will get harder and expensive.

Using the transfer hi/low switch to change engine maps would be awesome too! So does using a normal crank sensor! It’s not the cost with a crank sensor but you can run without one as well

Reinhoud

22nd November 2018, 07:58 AM

Hi all,

I've been having this problem that my engine usually want's to nearly stall if I try to move the car just a few meters when cold and in various other circumstances. I suspect the idle valve but am not sure how to test it. The first thing that came to mind is that nearly all vehicles I own or have owned have a high idle when cold, that is to say higher then when warm. My V8 has never had a high idle. not even when around the arctic circle at around -30c it's always 650-750 rpm. I thought that was because the V8 with the power strokes so close to each other simply does not need it but perhaps my car is simply broken but I never really noticed :)

So how do your P38's idle when cold?

-P

My P38 runs like a dream! Cold and even better when on temperature.

What type of sparkplug you have? They want the Champion ones.

DavidP38

23rd November 2018, 01:32 PM

so i should change the new BPR6Eix i just put in ? I have a bad'ish idle but I think it's the coil packs, never looked too much into it as it's good on fuel just a little erratic on idle for a V8

bee utey

23rd November 2018, 02:26 PM

so i should change the new BPR6Eix i just put in ? I have a bad'ish idle but I think it's the coil packs, never looked too much into it as it's good on fuel just a little erratic on idle for a V8

Perfectly good plugs if they're clean and properly gapped. It's a very long time since I've used Champions, no idea where they're made these days but they used to be absolute garbage 25 years ago.

TheTree

23rd November 2018, 08:20 PM

Hi

I use the NGK as well, they seem well suited

Steve

TheTree

23rd November 2018, 08:22 PM

so i should change the new BPR6Eix i just put in ? I have a bad'ish idle but I think it's the coil packs, never looked too much into it as it's good on fuel just a little erratic on idle for a V8

Coil packs and leads do have problems with corroded connections sometimes, it would be worth checking

Steve

Keithy P38

25th November 2018, 06:53 AM

All the P38’s I’ve worked on (both Gems and Thor) have been given the NGK treatment. I’ll never use champion plugs, they’re absolute rubbish. Only good for lawn mowers.

I have found that the rover V8 doesn’t like iridium plugs though. Just standard, correctly gapped plugs are perfectly fine.

Cheers
Keithy

prelude

5th January 2019, 12:05 AM

Hi guys, an update on the idle issue.

The IACV is working like it should as far as I can tell and the car has not stalled since a few weeks. The rpm still drops to far when idling forward or backwards etc. (read previous posts for the exact behaviour) but only down to, say, 400-ish in stead of (nearly) stalling. I would like it to run better but I guess for now it'll have to do. What I have found though is that the emission of the engine vary a lot, almost to much for the tester to measure quickly enough. When I test it on a higher RPM though, it is just fine. When I test it idling with my foot on the brake and the car in drive, it's also within acceptable levels. This is not allowed during official testing though.

Given that the engine RPM is also not stable when idling unloaded I am beginning to suspect that the ECU is constantly adjusting, slowing the engine down because the RPM is rising to much, speeding it up because the RPM is dropping. The measurements suggest high levels of unburned fuel and a bit to much oxygen at times. I have not yet found a way to adjust the idle RPM in the ecu but I could try and fool the system by adjusting the small screw on the throttle body. If that fixes my MOT problem I'll be happy for now :)

What I have also noticed is the backlight on the HEVAC to dim slightly when I hit the brakes. Also, the outside air temp is of by several degrees (almost always to low) sometimes when I start the vehicle. It takes it quite some time to get up to the correct reading. Perhaps there is a ground or power issues somewhere in the car that throws of the ECU. I know my intake air temp is always at least 20c or so to low so that might not help at all.

Keep you posted!
-P

biggin

5th January 2019, 07:19 AM

If your HEVAC light dims when applying the brakes, you definitely have an earthing problem. Most likely the route of your idling problem.
Check your earth points for a start.

TheTree

5th January 2019, 07:56 AM

Hi guys, an update on the idle issue.

What I have also noticed is the backlight on the HEVAC to dim slightly when I hit the brakes. Also, the outside air temp is of by several degrees (almost always to low) sometimes when I start the vehicle. It takes it quite some time to get up to the correct reading. Perhaps there is a ground or power issues somewhere in the car that throws of the ECU. I know my intake air temp is always at least 20c or so to low so that might not help at all.

Keep you posted!
-P

Hi

The outside air temp taking some time to get correct is deliberate design behaviour, that said it still sounds like you have an earth issue

I ran extra earthing cables between the earth points under the bonnet so it no longer relies on the connections to the body

Steve

PhilipA

5th January 2019, 08:43 AM

I have to qualify my comments by saying I am pretty experienced with 14CUX but not on GEMS.

The IACV is actually a stepper motor which has a little rack and pinion inside. If you move the shaft you basically destroy the stepper. There are widely varying qualities of steppers, and I would go for a more expensive "name brand". The IACV for a GEMS has different mounts to a 14CUX. Looks like the one used on GM engines. Some steppers have a different wire order in the plug than others so I would buy a specific GEMS stepper from a known source rather than a cheap stepper for a Jeep as this is a possibility.

I think your cam is the major problem. A cam that gives power from 2000-6500 is inappropriate for a RV8 in a 2+tonne vehicle. It will always feel dead at low revs and most of the time you will rarely exceed 2000-2500RPM. Great in a TVR but crap in a RRC. Although in the Netherlands I suppose there aren't many hills.LOL

Your idle changes when moving slowly are intriguing. The VSS gives a signal to the ECU to step up idle when the vehicle is moving slowly. This is designed to ease the change into first as the vehicle comes to a halt, but a byproduct is that as soon as you move slowly forwards of backwards the idle should step UP to around 1100RPM.
Regards Philip A

prelude

7th January 2019, 11:57 PM

Check on the earthing problem; I will give it some attention and perhaps, indeed, run an old piece of welding cable I have laying around as earth to bypass the body/chassis.

Regarding the cam: I never looked at it that way ;) I always figured, when wheeling and reaching a tough spot, say a muddy hillclimb, one usually chooses a gear and give it the boot. In those situations I definatly need the power curve to be above 2000rpm. Perhaps I am wrong here? I do notice the car to be sluggish in normal traffic but the 32" tyres combined with the standard diff ratio's does tend to do that anyway. I am not bothered by it really. It could still be though that the cam has too much overlap as suggested.

And hills? HA! you gotta be kidding me mate :) we have 2 to be exact and they are not what you would call a hill :P There is the "utrechtse heuvelrug" which is a ridge that was formed during the last ice age.
Utrecht Hill Ridge - Wikipedia (https://en.wikipedia.org/wiki/Utrecht_Hill_Ridge)
as you can see, with 68m at the highest point... not even worth mentioning. A 7% slope is the best I can give you over here :D Also there is a bit of a hill close to germany and way down in the south, none of them are more than a speedbump I suppose

The IACV I have right now is indeed a GM unit that fits the GEMS perfectly, except for the connector beeing at a different angle. When funds allow I will try the genuine article. I'll also try and record what the engine does using my faultmate but it seems that the ECU actually closes the IACV once a certain vehicle speed or engine rpm has been reached. Do you know of any such mechanic in the system to, for instance, avoid overspeeding or over idling?

Cheers,
-P

PhilipA

8th January 2019, 07:26 AM

The IACV I have right now is indeed a GM unit that fits the GEMS perfectly, except for the connector beeing at a different angle. When funds allow I will try the genuine article.

What I am saying is that the order of the wires in the plug may be different, and that when it should be increasing idle it may be decreasing idle. I really would try to get an IACV for a GEMS rather than try using a GM one.

In a 14CUX my guess is that the IACV closes at 1500RPM, as this is when injector cutoff on closed throttle occurs. I don't really know. As for GEMS I don't know. You could ask the GEMS people in UK if they are still around. In a 14CUX the IACV also opens and closes on shutdown to clean it.
Regards Philip AI
just had a google and it suggests tat GEMS is Lucas/Sagem.
Have you read this LUCAS GEMS (SM001) (https://blackbox-solutions.com/help/SM001.html)

4bee

8th January 2019, 09:26 AM

Apart from your immediate problems & slightly off topic I followed your link for the hill.

Bloody hell! They had a tough old time trying to retain it.

I dips me lid.

Utrecht Hill Ridge - Wikipedia (https://en.wikipedia.org/wiki/Utrecht_Hill_Ridge)

TheTree

8th January 2019, 09:35 AM

I fitted one of the Jeep IVAC units and it did not seem quite right so i went for the correct unit in the end

Steve

prelude

29th January 2019, 06:10 AM

And, last but not least, an update in this thread :)

I have not yet had the time (or money, sadly) to get an original IACV BUT! I have found a way around the crap idle and failing exhaust gas test. Since the exhaust gasses are way of when the car is idling but bang on target when at 2400rpm (the two engine speeds compulsory for passing the MOT) I figured the problem is probably in the ECU adjusting way to much at that low RPM. Others here have suggested as much as well. Since the idle rpm needs to be below 1000rpm for the MOT I figured, why not try to get the RPM up? Adjusting the idle screw would probably not make much of a difference I figured since that would not change enough in the ECU's map, I opted to tighten the throttle cable and with that change the TPS. Setting the RPM manually like this to 900rpm the MOT test succeeded so that is that problem solved [bigwhistle]

Like the oil leakage and the ETC, I am going to look into the IACV and the idle RPM a bit further when the weather starts playing nice down here. I had my petroleum heater on for the entire day last weekend working on the car and must have burned through at least $50 of fuel...

Cheers!
-P

4bee

29th January 2019, 07:53 AM

A while back on here I suggested exactly the same fix for my D1 but was hit with comments of possible problems by others here.

They haven't eventuated to the best of my knowledge & it has been very satisfactory, but it is too late now to be worrying about because I have traded her in for a Mazda CX-3 MAXX Sport.

Also glad to see they haven't made the list (yet???[bighmmm]) of Keyless Entry theft as per the UK report.

prelude

21st February 2019, 07:41 PM

A quick observation to add:

My daily driver conked out, fuel pump issues, so I took the range to get to work through heavy traffic. Since I was in a bit of a hurry I just started the car and drove of, never really reaching the point of crawling in idle, which in my mind is something that currently has to be done when cold to make sure it does not stall in idle later on. Once the engine heated up I had to stop for lights and the engine nearly stalled. Stop and go driving with the left foot on the brake and the right on the accelerator was getting real boring real fast though (to keep the engine running) so I turned of at a service station and turned the car of for a few minutes.

After starting her up and crawl forward for a couple of meters the idle issue was fixed and I got through the rest of traffic no drama's.

If the IACV is indeed buggered (wrong type) I would not expect restarting the car to fix the problem though I must admit that I tried restarting the vehicle to allow the IACV to reset itself to a default position (it does that when turning the car of for longer than xx seconds)

With my daily driver eating up funds to get fixed, buying a proper IACV is still on the horizon but I found this to be curious behaviour and thought I'd share :)

cheers!

-P