spark gap causing 94gt to lean???

[beaver2489]

My buddy has a '94 gt with 302 shortblock, TF twisted wedge heads, kenne bell custom cam, 1.6rr, TF track heat intake.....he has had this leaning out problem at high rpms since he got the car. It had the problem with the stock 302 setup in other words. Hes tried swaping computers, setting his timing and fuel pressure, and nothing works. He has to have his fuel pressure over 50 to not lean out up top, which makes for a rich low end. He gaps his spark plugs at .045. Could that be his problem? I know after '91 the coil output was raced and the spark plug gaps were widened. So in his '94 would his .045 gapping be causing his problem? His cam is installed straight up, base timing is 14* adv. and has tried 10*adv., and fuel pressure hes tried stock to 55. Thanks

 

[BlueDevil95]

First off, what size injectors is he running? He should have 24's with that setup. It could be a fuel pump going bad, clogged fuel filter or a mass air issue. Spark gap should not have that big of an effect here. I run anywhere from .35 on the bottle to .60 on the motor and no leaning out problems on pretty much the same setup. check the easy stuff first, vacuum leaks, change the fuel filter, etc.

 

[beaver2489]

he has a new 255 walbro fuel pump and filter, 75mm Pro-M meter with #24 injectors. and he has checked for vaccum leaks...but he could check again, thanks

 

[JJFIVEOH]

Is he running an MSD? I have a 6AL and found that my ETs are best at .068 gap. This wouldn't be the reason for it to run lean though.