VS Rough Running on Warm Start

[dammag]

VS V6 with 200,000Km's.

When I drive my car, park it and come back say 20 minutes later it runs very rough. It barely makes enough power to get up a hill. Even on the flat it accelerates very slowly. I think it's fuel starvation. It only does this when warm after sitting for 20 to 30 mins and never while just driving, no matter how long I drive for.

Any ideas?

Damian

 

[daza26]

I would say Angle crank sensor, it will eventually get worse than ur car will die n it won't start, nit to expensive to buy n if ur reasonably mechanically minded u can replace it yaself. Not a major job to replace I done mine n I ain't that mechanically minded lol.

 

[hako]

Also do a fault code check which is very easy: https://forums.justcommodores.com.au/threads/checking-error-codes-vr-vs-revised.22307

 

[Trikky]

also does it blow any smoke when it does this, it could be a leaky injector or two also check the vacuum line from the fuel regulator to the inlet manifold for signs of fuel as it is fairly common for the regulator to crap itself

 

[DAVO84]

try your coils aswell

 

[dammag]

Thanks for the replies.

I have fitted rec injectors and there is no smoke.

I have fitted a secondhand coil pack and base. No improvement.

No fault codes unfortunately.

I have ordered a crank angle sensor from ebay. Will try that next.

Damian.

 

[Brett_jjj]

You could try checking the fuel pressure regulator. When these fail, fuel gets down through the pressure regulator and down into the inlet manifold where it floods the engine. You wont really notice this problem when the car is running as the excess fuel just gets consumed, and you wont notice it after the car has been sitting for a while, or is started from cold, as any fuel thats leaked into the engine has had time to evaporate away, but when its been driven and then turned off, residual fuel pressure in the fuel system will cause fuel to continue to run down into the engine through the pressure regulator, and if the engine is then started again before this fuel has had time to evaporate away, the engine will run crook for a minute or two until it clears the excess fuel from the engine. A telltale sign is heaps of black smoke from the exhaust when the car is first started, as the excess fuel in the engine causes it to run heaps rich until its cleared itself.

 

[dammag]

Thanks Brett. I'll look into the fuel pressure regulator.

 

[dammag]

This afternoon I drove the car about 25 K's, turned it off for 20 minutes and it restarted OK. I then drove another 25 K's, filled up with fuel (E10 which I prefer not to use) started OK after say 4 minutes. Drove 1 K then stopped for 5 minutes, started OK. Drove 200 metres, stopped for 15 minutes, car started but very rough. Drove 50 m it stalled while driving, couldn't restart. While it was running during this 50m it sounded like it was pinging. Went home, had dinner, walked back to car and after a couple of try's it started and ran smooth again. I didn't check the fault codes when it wouldn't start as I had my 4 year old with me and I was pissed off.

Can you check for error codes with the car running or is it only stored codes with the ignition on the second click?