My borther has an 89 IROC, 305, auto, and the car runs like it is missing. We've checked the wires(replaced), checked the plugs(replaced), checked fuel pressure(40psi), and replaced the fuel filter. Nothing seems to help. If we start the car it runs like it's not firing on 1 cyclinder but everything looks like it's running like normal. If he drives the car eventually will die but will start back up.

Any suggestions at this point would be appreciated. Thanks.

------------------
'91 Z-28 5.7, SLP 1 3/4 headers, 4 inch Mufflex/Flowmaster cat back, gutted cats, Edelbrock intake, 8.5mm Jacob wires, MSD Blaster coil, S&W subframe setup, Jacob Pro Street Ignition, complete Kenwood system.

 

Nevermind....figured it out.

 

Well, what was the fix ?

 

2 bad injectors. I ran ohm readings and #3 was at 8 ohms and 5 was at 1. After replacing #5, the car ran 200% better. Will be replacing #3 in a week.

 

Had the same problem awhile back. Sure enough a couple bad wires going to #4 injector! Felt like I gained 50 hp+.