VP Idle Probs

[nathanashton]

Having a heap of dramas lately with the idle on my 93 Calais. When stationary with the engine idling it varies between about 800rpm down to almost 200rpm. Jumping around heaps. Does this in Park, Neutral or Drive - doesnt seem to matter. Also when pulling up to a halt as the car changes down the gears the revs drop right down and the car has even stalled a few times which isnt a good look There is also a strong petrol smell at times and the car seems to blow a bit of smoke when starting.

I've cleaned the throttle body, IAC, checked for vacuum leaks and replaced the o2 Sensor as I was getting a Code 13. Didnt seem to make any difference. Car runs great normally - just the idle which is cactus.

Any ideas where to look next?

Cheers

[b3h3m07h]

i have a very similar problem but on gas. I also replaced my O2 sensor and have notice better fuel economy but still rough idle. im pretty sure that its my coils though as 1 of the 3 has a high resistance, about 8.50 ohms compared to the others at about 6.5 so ill be replacing that soon. Does you engine mis fire at all and also try disconnect the battery leave it for a minute then reconnect, start car, rev at 2000rpm for about 10-15 seconds and see how it is then. If no change to idle is seen id say either leads, spark plugs, coils, DFI module, possibly a valve or CAS (crank angle sensor). Best of luck

[nathanashton]

Dont have any problems with misfiring. Once the car is off idle it runs really sweet. I have disconnected the battery and done the rev thing the other day. It seems to help for about half a day then the idle problems gradually return again. Not sure if it's related but when I stop and put the car in "park" in stalls probably 90% of the time. Put it in neutral and it just keeps idling rough. Its got me stumped.

Thanks for the help

[trickw]

check your fuel pressure regulater, Change fuel filter and see how you go

[peter65]

hmmm. i had a few idle probs with my vp 3.8L. I cleaned the throttle body (which you have done) & cleaned/reset the (Delco platinum) plugs. i also put fuel injector cleaner thru it every 2500km & now run it on shell premium ulp which seems to have helped as well. The donk has 300kkm on it..... some more things for you to try on a rainy day.... cheers peter.

[vq_statss]

just a guess could it be the inibator switch....my 5lt is the same done leads plugs rotor button still the same..it smells like urs and blows black smoke on start up but then revs fine....but its stallin somtimes and somdays u get a miss for 10 or 20 mins then gos away...tthought it was when its hot but done it after 2 mins of driven and then went fine..

[88GreenVN]

Check the connector for the oxy sensor - code 13 is open circuit so the connector may be bad. Was bad on my car - cut the connector out and put in a crimp terminal - car runs fine.

[Benji]

adjust your base idle ?????

[nathanashton]

Quick update on things so far. Booked it in for the pros to have a look at. Spent the whole day yesterday on it and couldn't find what the problem might be. Had another look this morning and apparently the fuel pressure it too high, and the regulator might need replacing. Might actually be getting somewhere now .....

[nathanashton]

Problem now solved.

Fuel Regulator wasn''t working or broken or something like that. Oxygen Sensor plug wiring was also frayed in places. Everything reset and now running sweet.

Thanks for the help guys. Might help someone else having similar problems.