TBI wierd idle when I turned A/C
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From: Long Beach, CaLi.
Car: 95 MC Z34, 93 Caprice LTZ L05
Engine: 3.4 DOHC, 5.7L TBI
Transmission: Auto, 700R
Axle/Gears: ???, 3.08
TBI wierd idle when I turned A/C
Hello All,
I have been trying to hunt down a weird shake I feel when I come to a stop in a red light. 2 wks ago I did the plugs to ac rapid fires, added my MSD wires and oild change to prepare it for the smog here in Cali, passed with flying colors. I have been feeling this weird shake, feels like it is going to die on me but it does not. The fuel pump was changed out 2 yrs ago and I have not driven it 5k miles yet since and I do not let it go past the half mark on the tank cause I don't want to overheat the pump. All sensors that control the ECM have been replaced, including a new Denso O2 sensor. I have not rebuilt the TB though and have not tested fuel pressure.
To make the long story short, I was cruising and I came to a stop and turned on the A/C and the RPMs started to jump around as if hunting idle then it returned to normal. Could the IAC be going bad or could it be the ECT sensor going out. I really am trying not to spend too much.
Car info: 1993 Caprice LTZ L05 TBI - 185k miles, MSD coil, wires, cap and rotor, dual exhaust after cat (put new 2 yrs ago), JET chip, rebuilt tranny with shift kit, F-Body EGR.
I have been trying to hunt down a weird shake I feel when I come to a stop in a red light. 2 wks ago I did the plugs to ac rapid fires, added my MSD wires and oild change to prepare it for the smog here in Cali, passed with flying colors. I have been feeling this weird shake, feels like it is going to die on me but it does not. The fuel pump was changed out 2 yrs ago and I have not driven it 5k miles yet since and I do not let it go past the half mark on the tank cause I don't want to overheat the pump. All sensors that control the ECM have been replaced, including a new Denso O2 sensor. I have not rebuilt the TB though and have not tested fuel pressure.
To make the long story short, I was cruising and I came to a stop and turned on the A/C and the RPMs started to jump around as if hunting idle then it returned to normal. Could the IAC be going bad or could it be the ECT sensor going out. I really am trying not to spend too much.
Car info: 1993 Caprice LTZ L05 TBI - 185k miles, MSD coil, wires, cap and rotor, dual exhaust after cat (put new 2 yrs ago), JET chip, rebuilt tranny with shift kit, F-Body EGR.
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Joined: Dec 2012
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Car: 1992 Camaro RS 25th Anniversary
Engine: 305 TBI
Transmission: 700r4
Re: TBI wierd idle when I turned A/C
I cant help you out with that a lot but heres a couple of things from my recent experiences.
- Im not sure if a 93 uses OBD1, but if it does(probably does), you should probably check for any trouble codes. Have you done this?
-I recently had a IAC go out on me. I dont think thats what your experiencing. A bad IAC forms basically a huge vacuum leak, making idle rpm super high. It will not throw a SES light or trouble code. If you think your IAC is not sealing well/ operating properly, take of the air cleaner. If the IAC is bad the sound of the engine pulling vacuum at idle will hurt your ears, lol.
-as for the ECT, hmm, im not sure. If you have a friend at a autoparts store, ask them if they will let you buy one, test it, and return it if it doesnt help.
-also check this out.
OBD1 trouble codes
code 14 Engine coolant temp sensor error (high temp indicated)
code 15 Engine coolant temp sensor error (low temp indicated)
perhaps that will help you out with your problem?
how is 5.7 TBI? i would like to toss a l05 into my maro, hows that combo you listed at the bottom run?
- Im not sure if a 93 uses OBD1, but if it does(probably does), you should probably check for any trouble codes. Have you done this?
-I recently had a IAC go out on me. I dont think thats what your experiencing. A bad IAC forms basically a huge vacuum leak, making idle rpm super high. It will not throw a SES light or trouble code. If you think your IAC is not sealing well/ operating properly, take of the air cleaner. If the IAC is bad the sound of the engine pulling vacuum at idle will hurt your ears, lol.
-as for the ECT, hmm, im not sure. If you have a friend at a autoparts store, ask them if they will let you buy one, test it, and return it if it doesnt help.
-also check this out.
OBD1 trouble codes
code 14 Engine coolant temp sensor error (high temp indicated)
code 15 Engine coolant temp sensor error (low temp indicated)
perhaps that will help you out with your problem?
how is 5.7 TBI? i would like to toss a l05 into my maro, hows that combo you listed at the bottom run?
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