93 z runs fine when open loop,like crap in closed, WHY?
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Joined: Feb 2000
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From: fl,jax
Re: 93 z runs fine when open loop,like crap in closed, WHY?
I am using a scan tool to get the readings from the PCM I think it is actron (kinda cheap) is it possible the fuel regulator is bad?
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Joined: Sep 2004
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Re: 93 z runs fine when open loop,like crap in closed, WHY?
Mine had a problem with closed loop in that the PCM always saw a rich O2 on the driver side and would run like crap. Forced it to open loop and it ran as well as any could in open loop. Changed the O2 as anyone would and scanned it with KOEO and you could watch the O2 reading drift to completely pegged rich. Hadn't even run the engine with the new O2 yet mind you. I have found that with KOEO the O2 readings should gradually drift to a lean reading, not full rich obviously.
Double checked for bad wiring to the O2 and finally found out the PCM circuit used for the O2 was defective. So new PCM it was. Now that problem is fixed I can focus on the "other" problem.
Double checked for bad wiring to the O2 and finally found out the PCM circuit used for the O2 was defective. So new PCM it was. Now that problem is fixed I can focus on the "other" problem.
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supercharged94Z28
LT1 Based Engine Tech
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Feb 24, 2003 10:22 PM
