General Chat
Q:
First of all, I have a draw-through setup in my Z (carb'd turbo for those who don't know). I took out the carb before I left for school but put it back in because I didn't have time to take it somewhere to have it looked at and I didn't want to let mice get into the turbo (the garage is infested with mice and I just recently found an outdoor cat to neutralize that problem).
My problem is mainly that the engine pings and knocks terribly, and sometimes there is a huge backfire through the carb. I've been all over the spectrum as far as timing goes, i've changed plugs three times, which were gapped at .041 (what they were gapped at when I bought the car; when it worked PERFECTLY.) I actually used NGK's (obviously the right kind for my motor, Flat-topped L28 with an E-88 Head, and there is never really a problem with the plugs being a weird color, they are a light brown color, not burnt, and definitely not sooty. I have changed plug wires once (they are put on the right plugs, so that's not the reason for the backfire), and there are no vacuum leaks that I could find.
ANYWAY, I was wondering if you guys had any suggestions about what my problem could be before I take out the carb again. The carb is probably bad and maybe does not deliver enough fuel to the engine, but could there be something else? I don't think I have a blown head gasket, because I'm not losing coolant out of the pipe (I WAS losing it out of a hole in the radiator but that has been since patched and I no longer lose coolant). The dizzy cap is good and the distributor delivers enough spark, and the fuel pump seems to be good and I just replaced the fuel filter. I just don't get it!
Any ideas? If you need more info, just ask and i'll tell.
1976 280Z
Draw-Through Turbo, 10 PSI, 4 Bbl Holley, E88, L28 (Flat), 10:1 CR, 5 Spd
1974 Corvette Stingray:
350, 400 Automatic, T-Tops, 8.5:1 CR, 78,000 Miles
1994 Acura Integra:
1.8L, 5 Spd, 189,000 and Counting!
A:
Timing or need higher octane fuel (I doubt octane is a problem though, but possible).
A:
fuel delivery problem (clogged tank, weak pump, clogged line, improper fuel pressure, carb problem).
Distributor advance is stuck in a very advanced state (check timing)
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A:
OH yea I DO use 93 octane, it did ping minimally before all of the severe troubles happened; I never got to try it on a higher octane.
1976 280Z
Draw-Through Turbo, 10 PSI, 4 Bbl Holley, E88, L28 (Flat), 10:1 CR, 5 Spd
1974 Corvette Stingray:
350, 400 Automatic, T-Tops, 8.5:1 CR, 78,000 Miles
1994 Acura Integra:
1.8L, 5 Spd, 189,000 and Counting!