I have an 88 IROC with 5.7 TPI in it. Starts and drives perfect but at part throttle, cruising, I get some serious stumbling and slight hesitation. At WOT I get some slight stumbling as well.

I cleaned the intake/throttle body up. Doesnt appear there are any fuel leaks. I checked the base timing which was at 10*, so I set it to 6*. Seemed to work pretty well for a couple minutes (couldve just been because it was freshly started) and then back to the typical issue. I checked timing again and it was still at 6*, after I plugged everything back in, it was sitting far to the passenger side, maybe around 20*.

I have an Accel coil and 8.8 plug wires. From what I've read, check the cap/rotor and ICM and also check fuel injectors due to possibly being clogged, and replace fuel filter? Could the MAF or TPS be causing it as well? And I've also read that a stock cat could be an issue?

No SES light on but I also havent checked

 

As an update, changed the TPS (set at .54 volts) and MAF. Checked all the injectors which came back 16.5 ohms.

Attempted to check for codes but my check engine light appears to not be working whatsoever. Bulb is plugged in and connected, so I'll try and figure that out this weekend through some wiring diagrams I found on here.

Besides that, I'll pull the plugs then possibly the injectors to try and clean em.

 

so if you jump the pins in the diagnostic port the check engine light doesn't come on or flash? If the wiring is good you may be looking at a ECU issue (or wiring to it), though start with inspecting the wiring etc and don't go throwing a new ECU in quite yet.

 

Yeah, I figured I would check fuses and wiring/connections first, might make an afternoon of it tomorrow now.

https://www.thirdgen.org/forums/dfi-...ine-light.html

I got some good information from this thread.