Pac_Man Posted October 4, 2015 Share Posted October 4, 2015 Well my car has been at the point where I can actually drive it around for a while now but I have some gremlins which make it kind of sketchy and I want to try to pin down what my issue(s) is/are. Background of the car: 1976 280z, l28et swap Stock engine setup and ECCS, z31 coil, EGR deleted and blocked off, pop off valve removed and plugged. New battery. Alternator tests good. Brand new CHTS. New aftermarket FPR with a pressure gauge. Brand new O2 sensor. My issue lies in air/fuel ratio... I have a wideband gauge which I know isn't precise but can at least give me an idea of what the car is doing. Startup is difficult, and I'm under the impression that it's because the mixture isn't rich enough for easy fireup. Idle upon startup shows lean. Idle is also a bit high at ~1100 rpm. Not sure if that could be the cause, but I haven't been able to find any indication of idle adjustment on the L28ET throttle body like people have mentioned. The odd thing is after driving the car around and letting it warm up, idle AFR shows normal with a bias towards rich, which seems to be as it should be. Things get weirder, and this is why I think I have some kind of issue with grounds or something. Driving around normally, I can turn my headlights on and the mixture will go from slightly rich to slightly lean. Driving around with the headlights on indicate that it has a permanent issue of running lean with the lights on. I've had a heck of a time finding any indication of what could cause this specific issue, both looking through the FSM and google. I'm hoping someone on here can give me assistance since at this point I feel I'm in over my head. Thanks in advance, Pac_Man Quote Link to comment Share on other sites More sharing options...
NewZed Posted October 5, 2015 Share Posted October 5, 2015 Things get weirder, and this is why I think I have some kind of issue with grounds or something. Driving around normally, I can turn my headlights on and the mixture will go from slightly rich to slightly lean. Driving around with the headlights on indicate that it has a permanent issue of running lean with the lights on. Does the way the engine runs change? Sound or performance? Could be that your gauge is affected but not the actual AFR. Bad gauge readings can lead you on a wild goose chase. Quote Link to comment Share on other sites More sharing options...
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