Quote:
Originally Posted by Gaz64
Greg, I work For Holden, I have a few questions and hopefully will be able to help you.
What ECM are you using, factory or aftermarket?
If it's factory are you using the AFM or has it got a mafless tune?
While searching for a misfire/flatspot etc, you should not disconnect the sparkplugs with the engine running.
What happens is the other three on that bank will go richer to compensate for the high oxygen content emitted from the cylinder you cause the misfire on. Although unburnt fuel comes out the exhaust port, it's the oxygen we haven't used that causes the others to go rich.
Have you put TECH 2 on yet to see what codes (if any) are stored.
Lean bank DTCs P0170, P0171 are common and PCV ventilation hose or loose intake gaskets are common.
If you can drive through the flat spot and it makes good power, then you can count the fuel system and the igntion system out. I'd say you might have a fuel trim issue, look at data display STFT and LTFT.
|
Thanks Gary for the suggestions.
I am running a stock ECU and tune with MAF.
No I havent put a TECH 2 on to see what the ECU thinks. I dont have access to one or know someone who has one at present.
I will double check the PCV hose and intake gaskets.
I wouldnt say it is making good power at the moment (say medium power at present), you can increase revs at a medium pace but when you give it a bit it struggles.
I am still suspect on the ignition system. Am changing the plugs tomorrow to rule them out.
Was thinking if that doesnt resolve it to double check the coils are ok somehow.
Then trying to find someone with TECH 2 to see what codes are being stored etc.
Last resort was a compression check?
Rgds
Gregg