engine idol problem

[richhy]

Any mechanics out there? when i start the chim in the morning i seem to be suffering from some hesitation when i try and blip the throttle. This eventually goes after a mile ish, but the main problem is the idol. When i approach a junction and push the clutch in, coming to a stop, the engine seems to rev up to about 1500 rpm. it will only return to 1000 once the car is stationary. ????????

[Corin Denton]

Stepper motor might need cleaning?

[richhy]

recently fitted a new stepper motor and it didnt make a difference.......

[Corin Denton]

A lot of them are really lumpy from cold, more noticeable in the colder months. All the HT setup O.K? Plugs etc.

What fuel do you use?

[richhy]

yeah, plugs etc all fine, although someone did mention a road speed sensor? might check it out. use normal unleaded

[Hut49]

Could be either or both of the Lambda sensors or temp sensors.....the list is pretty long. Best to get a proper diagnostics unit on it at a local indie and save yourself all the hassle of replacing this and that and finding it's no better. That can get expensive and spoil the fun.

[pullingpower]

Mine does this too, usually when cold. Will idle at 1200 when coasting then drop just below 1000 when the car is stationary like yours.
As not had the car long, was not sure if this was a common feature for Chim or not?

[HarryW]

I always thought of the RV8 as iconic not an idol myself .
As already said try the stepper motor cleaning routine first .

Harry

Just re-read the post and yes you've already done the stpper dance, however did you also clean the housing/plenum side of it too .

>> Edited by HarryW on Tuesday 26th October 23:05

[chimtvr]

first thing to try disconnect the engine ecu by the fuse box for about 30 seconds then plug back in and try from cold
Basically this will reset the ecu back to original settings
if you have any faulty sensors the ecu will adjust fuel trims to try and sort the problem sometimes it gets it wrong
tell me what happens

[chimtvr]

also the engine revs are supposed to be held up during coasting once you come to a halt they should return to idle

[HarryW]

chimtvr said:

first thing to try disconnect the engine ecu by the fuse box for about 30 seconds then plug back in and try from cold Basically this will reset the ecu back to original settings if you have any faulty sensors the ecu will adjust fuel trims to try and sort the problem sometimes it gets it wrong tell me what happens

Good point, seem to remember part of the clean the stepper bit was to reset the ECU anyway as it might have learnt bad manners. If there is still a problem it will come back.

Harry

[longjon]

I posted a thread with the same issue. My problem has now kind of gone away but comes back intermittently. Someone suggested that it was to maintain servo pressure for braking?

Old thread:

www.pistonheads.com/gassing/topic.asp?f=8&h=&t=125608

[derf]

Mine does this and I was told the old 'They all do that sir' but also told to try blipping it to 3000rpm after start three times. I think it helps but it may just make me feel good because of the noise.

I also find doing this makes the whole area stink of petrol for a while! Does anyone know if this is ok as it will be rich from the cold start or should I wheel it back in to be looked at?