VP refuses to idle when cold

[adamu]

Hi, first time post here. I've had a VP for a couple of years and it's always had a problem where when cold, she starts just fine and idles well until i rev the motor (or drive) which causes the idle RPM to drop and normally stall. Then the problem persists when i try to restart the car. The only solution is to keep my foot on the accelerator. Strangely, when the car warms up the computer seems to fix the idle and everything works perfectly. I'm suspecting something to do with the air intake because the same problem happens on both LPG and petrol? Thanks, Adam.

[Chirpstr]

Check codes, sounds like she's flooding. Could be a faulty coolant temp sensor if its doing it only when cold. Could be a number of things really.

http://forums.justcommodores.com.au/...s-revised.html

[adamu]

I just checked the error codes by hooking up my laptop. Only listed 45 (oxygen rich)... but for what it's worth this code is only triggered when the car is warm and I'm driving (eg. going down a hill). Is the O2 sensor voltage meant to be jumping around? See sensor data in word doc attached.

[vn calais manual]

oxygen sensor is inactive until operating temp

[Chirpstr]

Could be a faulty O2 sensor. Mine was doing that, don't know if it still is after replacement....I have a feeling though they are meant to be a little bit erratic when warming up. Don't quote me on that though lol.

[89 vn]

I know someone with a stalling problem when cold, he got his revs raised a bit so now his car idles a bit higher but it idles well in the cold and doesnt stall maybe that could help you

Also I had a stalling problem at all times cold or hot w/e the car just stalled without a set reason my mechanic replaced something inside my pump and that fixed it. Eventually it got so bad that as soon as i turned the car on it would just die and the life would be choked out and I would have to get it revs just to keep it alive and took me 15 mins to drive about 1 km maybe have a look at your pump too.

[adamu]

My fuel pump is broken at the moment so I'm just running on gas (after the 3rd pump you'd think I would learn to run it occasionally on petrol)! I don't think it's the oxygen sensor b/c it only idles low when cold. I just pulled apart the throttle body and gave it a good clean but i was wondering, with the IAC should i be able to move the valve? i can't twist it or push/pull it at all so does that mean it's seized?

[accentstencil]

My fuel pump is broken at the moment so I'm just running on gas (after the 3rd pump you'd think I would learn to run it occasionally on petrol)! I don't think it's the oxygen sensor b/c it only idles low when cold. I just pulled apart the throttle body and gave it a good clean but i was wondering, with the IAC should i be able to move the valve? i can't twist it or push/pull it at all so does that mean it's seized?

You should be able to move the pintle of the IAC valve in and out, so I would say you need a new IAC valve. HOLDEN VN-VY IDLE SPEED/IDLE AIR CONTROL/STEPPER MOTOR - eBay, Other Car Parts, Accessories, Car Parts, Accessories, Cars, Bikes, Boats. (end time 11-Jun-08 07:20:03 AEST)

[adamu]

Well, I just put a new IAC valve in and hey presto, problem solved. I think the fact that it never set a fault code shows that the ECU is good as a guide but isn't the be all and end all for solving problems. For what it's worth my mechanic was never able to figure out the cause of this problem! Cheers for your help guys.