View Full Version : Cr#p idle - TPS adjustment
After having loads of idle/starting problems I've now been through all the management sensors and basically replaced the lot. The starting problem turned out to be the coil pack so replaced that but then it still wouldn't idle well when warm so I've now replaced:
-ISCV (new Bosch, £££ ouch)
-Map sensor (new OEM)
-IAS (new OEM)
-CTS (new OEM)
-Lambda (new Bosch)
-TPS (new TT electronics Germany)
Also I've been through all the wires going into the ECU plug and checked the resistances and all ok despite frantic wiggling of connectors to check for dodgy connections etc.
Thing is it still doesn't idle well when warm (drat!). Revs vary between 450 (ish) & 900 (ish) and feels like it wants to stall at the lower idle.
I read that the TPS should be set to 0.2V (closed throttle) & 4.55V (full throttle) so I tried to do that and set it to 0.2V at closed throttle but only goes up to 4.43V at full throttle! Is this a problem?
Only other things I can think of (or haven't replaced) are Speedo cable/VSS and ECU. Looked inside the ECU and all looks lovely but who can tell, definitely no dodgy aftermarket chips though.
Any ideas or advice would be much appreciated, still haven't driven it more than round the block for fear of it conking out (again).
Cheers
Andy
Also replaced flywheel sensor........forgot about that.
Christ, that's a fair amount you've replaced there, and still no joy?
So, at cold start it seems ok right? Idles a bit high and leans off as it gets warmer?
I would be looking at the fuelling, if you've been over the electrics. It could be in need of a new fuel filter or cleaning the injectors or checking the fuel pump wiring.
MatBrown
04-07-2011, 00:06
Air leak anywhere?
I can now offer clip services.
Yeah I was wondering about fuelling as everything I've used is in unknown condition. The injectors came with the car as spares and were (aledgedly) ultrasonically cleaned but can't be sure, fuel pressure regulator is unknown. I've got a new fuel filter that I'll be fitting asap.
That's part of the problem with not buying a properly running car and not really driving it before ripping it to pieces because I'm just guessing that everythings in working condition.
I think its free of air leaks because when you block off the ISCV pipe from the air filter it stalls instantly. I'm not convinced about vacuum leaks being the problem either as I can't find any dodgy hoses and I've replaced the MAP sensor ones with new silicon hose.
Matt, I thought you were on holiday?! Surely the other half won't be too impressed with you answering technical queries while sat on the beach!
Sorry, yeah when you first start it from cold it idles at 900 pretty much rock solidly but then when it starts to warm up the idle just starts getting more and more unsteady with the revs climbing and then falling. Once full warmed it will start but the revs just drop off and virtually stalls.
No point taking it for a spin as it'll just conk out when you dip the clutch. It actually stalled once on the way back from MOTing (under load too) and then wouldn't run at all until cooled down. My Dad had collected it and it had snuffed it about a mile away from home in the middle of York races traffic, nice.
Are you sure it isn't something internal in the engine? Could it be an issue with the headgasket becoming more prominant when warm?
The engines been fully rebuilt (by me though) with new gaskets etc. Plus theres no evidence of oil in the coolant so I'd be surprised if it was head gasket and it runs ok until warm (a bit of top end rattle though).
Do the revs fluctuate even when warm from normal rpm to really low? Or is it low all the time?
The engines been fully rebuilt (by me though) with new gaskets etc. Plus theres no evidence of oil in the coolant so I'd be surprised if it was head gasket and it runs ok until warm (a bit of top end rattle though).
The headgasket can go in several places, so there wouldn't always be oil in the coolant. If you've rebuilt it though I doubt it'll be that!
Yeah shouldn't be the head gasket.
The idle fluctuates when warm yes from normal idle to low and then when fully warm it will start but just not maintain any real idle speed.
MatBrown
05-07-2011, 00:34
Matt, I thought you were on holiday?! Surely the other half won't be too impressed with you answering technical queries while sat on the beach!
Hehe, I'm never totally on holiday!
Bitten the bullet and taken it to a management specialist I've used before and if he can't fix it then I'll know that I am not destined to enjoy Renault ownership and that generally the french hate me.
The specialist guy has now found the problem, after three and a half days of solid labour (£££!) it turned out to be a faulty bloody ignition coil even though this was replaced a couple of weeks ago with a new Lucas part! Who would've thought that!?
So now that problem has been solved, just long enough for another problem to leap into it's wake! The specialist now says the engine has developed a top end rattle/rapping noise which he reckons might be oil starvation to the cams/lifters..............f#*king joy, I hate this car!
So looks like engine out for the 3rd or 4th time, lost count. Now contemplating self harm.
Before you take it apart, just get the car back, check oil level, and run it for a bit. It may just be tappets and it needing a good run.
Tappets are not that hard if it's just them.
It had 16 new tappets as part of the rebuild so i think it must be oil starvation to the lifters or head generally. I made sure i blew out all the oil holes in the cam journals etc with the air line when it was apart so can t see how they ve got blocked since then. Plus oil pump was brand new so pressure should be good.
I wondered if it might be rattling because it hadn t been driven and just idled for long periods but not sure. Will find out when i get it back.
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