Here's the deal, just brought a 91 z28 camaro with a 305 engine. When i first got her, she was running a little rough and had a misfire problem. Since then ive changed plugs, wires, distributor, coil, pcv valve, fuel pump, and a couple of things that dont relate.

The problem is now shes running pretty well, but still is not at max potential. Also, a stutter occurs during cruising speeds but by putting my foot on the accel or clutch the problem with go away. any suggestions are appreciated.

Have a full flowmaster with hooker headers with no o2 sensors or egr valve would that have anything to do with this problem.

Thanks again,
Reggie

 

I have this same problem. Mine is a 91 with a tpi 305, and just maintaining speed it starts to jerk and buck. I was thinking that maybe I had a miss, and will replace the plugs and wires next week with some accel wires and decent plugs. I have checked to make sure I had the correct mem-cal in because someone suggested that I might have a 350 prom, but the one I have is correct. The only other things it could be, that is, things I haven't replaced already, is my throttle body, which sometimes stick open 1% and won't let it idle down till I give it a healthy tap on the throttle, or bad injectors. The injectors are something I was also wondering about because I have found a good set of injectors fairly cheap but they are for the 350, which use a 22 pph injector versus my 305's 19 pph. Think it would be already to put the 350 ones in?

 

If the engine is fuel injected it needs O2 sensor/s, otherwise the ECM does not know what the fuel mixture is and runs on open loop mode. Not a good way to run.

 

yea, the O2 sensor being out will cause that. have a shop drill a hole and weld in an O2 bung if you can't and reinstall the O2 sensor.

 

Well I have replaced my o2 sensor, don't know about BigReg, but it was staying in open loop and didn't realize that until I got a scan tool. But it will still do this. it doesn't do it as bad when it's cold. Do you think the plugs could have got fouled because it was running on open loop for a while?

 

its very much possible they could have fouled. take them out and see if they are. let us know what color the ceramic is around the electrode.

 

turns out my cam was lobed off, so i sent my heads out, new cam and lifters. Switched it over to a carb set up also and got rid of that computer. runs a lot better now. Got a little cooling problem now though.