Fluctuating acceleration

[ss_2211]

I have an 06 model VE Commodore, and to cut a long story short, I had to replace its throttle body last year because the engine / acceleration would fluctuate even when the pedal was held in one place (particularly up hills), the check engine light would come on and the stability control would also turn off and on by itself. On a few occasions the engine even went into safe mode (or low power mode or something like that) and Holden advised that the throttle body needed replacing which I did. It took Holden a few visits to figure it out.

Now about 12 months later, the fluctuating acceleration is back and wondering if anyone has any suggestions on what it could be before I have to spend an arm and a leg again at Holden. It basically off a standing start, the pedal will be held at one place, but the acceleration comes in bursts….

Thanks in advance

[Z3RO]

Do you have an aftermarket CAI?

[Johnsy]

Have you owned the car from new ? Or done any mods to it ? If yes and no.... i would look at where you get your fuel and change your filter in the fuel tank.

[UFO]

do you normally fill at one particular service station?
the fact that the problem has returned only after a year tells me crap fuel is going in.

fuel tank filter isnt a serviceable item, so changing that is going to be a bitch.

[ss_2211]

I bought it about 3 yrs ago, its just a standard 06 Omega, no modifications, all the stock parts fitted. I usually fill up at Woolworths petrol but tried BP the other day on an empty tank and the problem is still there. Have booked it into Holden to have a look at, I suspect that all they'll do is plug in the diagnosis machine, tell me there's no codes playing up and say that they cant find anything.

[Z3RO]

P0101
p0068

[aaronevolution]

I bought it about 3 yrs ago, its just a standard 06 Omega, no modifications, all the stock parts fitted. I usually fill up at Woolworths petrol but tried BP the other day on an empty tank and the problem is still there. Have booked it into Holden to have a look at, I suspect that all they'll do is plug in the diagnosis machine, tell me there's no codes playing up and say that they cant find anything.

Filling up one tank worth won't fix it. You will need multiple tanks to get rid of the crap fuel.

[ss_2211]

Could it be something to do with the MAF sensor?

[BumbleBeeSSVR]

I've noticed the same thing but mines a 2010. Its done it maybe 2-3 times in the 1500k's or so I've owned it

[carcollector]

Try cleaning the throttle body with a spray pack/aerosol throttle body/carby cleaner. Sometimes they get a buildup of junk behind the throttle butterfly just off idle, and that causes them to stick, then let go and move on to the correct throttle position. This can cause what you've described. Normally you'd get a fault code though, which will cause the engine to go into safe mode as you've described.

The other possibility is that the throttle pedal itself is faulty. It has an accelerator pedal position sensor built into it.

[ss_2211]

Took it to Holden this morning. They looked at it and said that the 'PCV' was clogged. So they've unclogged it and reset the system. Should be interesting to drive it when I pick it up.

[Johnsy]

So how is it running now ?