[rednhez]

the car is a 99 mk3 golf 8v turbo. running c2 42# software, and about 10psi of boost with a t3super60 turbo. car runs fine unless i get on it and then it falls flat on its face around 4500 rpm. check engine starts blinking (misfire) and a vagcom scan says it had misfired. i replaced the coil 3 months ago with a autozone duralast coil, and i'm running ngk bkr7e plugs gaped at .025.
it only misfires under higher boost levels, whats wrong? i have no idea. TIA

 

[TBT-Syncro]

Re: getting missfires up top under boost (rednhez)

what does the wideband say? hint hint

 

[rednhez]

Re: getting missfires up top under boost (TBT-Syncro)

damnit i knew someone would ask that, i was just hoping that it wasn't the first post haha. well i have a new walbro in tank 255lph fuel pump. and no wideband. but i used the vagcom spreadsheet to calculate air/fuel using injector pulse, and its running WAY rich, like 9:1 and i think fouling the plugs, causing the misfire. because it misfires and then continues to misfire for a while even after letting off it. but idk how to adjust that since it is c2 software.


Modified by rednhez at 7:23 PM 8-31-2009

 

[TBT-Syncro]

Re: getting missfires up top under boost (rednhez)

if its running pig rich, there is a problem with the hardware.
step 1. with a vag-com, and the car idling. see what the 02 trim and maf readings are.

 

[rednhez]

Re: getting missfires up top under boost (TBT-Syncro)

i'll check those tomorrow. what are the ideal values i should have?

 

[TBT-Syncro]

Re: getting missfires up top under boost (rednhez)

Quote, originally posted by rednhez »

i'll check those tomorrow. what are the ideal values i should have?

idle 02 fuel trim should be almost zero 1-2%

 

[KubotaPowered]

Re: getting missfires up top under boost (rednhez)

Close the gap a tad more maybe? Also check the conditon of the plug wires as well as the cap and rotor.

 

[rednhez]

Re: getting missfires up top under boost (KubotaPowered)

i originally had the plugs at stock gap and i saw zero improvement to going smaller. just throwing that out there.
i'm waiting for my ghetto laptop to charge so i can scan again. i'm using duralast plug wires too. they have a lifetime warranty so autozone should just replace them.

 

[rednhez]

Re: getting missfires up top under boost (TBT-Syncro)

maf reading is 2.29 g/s idk what you mean by 02 trim though. do you know what block that is?