I have a 94z and last week i replaced the fuel pump because it went out on me completely. I drove it for about a week with no problems. Then i filled it up one night with some fuel injector cleaner in the gas and it still drove fine. The next time that i filled it up though, about 2 hours alter when i went to start it, it hesitated a little, then it felt like that car had a misfire when i got on it slightly. After driving it for a few minutes i could feel it badly underpower, but when i would open it up it would hesitate real bad then launch beautifully, like no power was lost.

The next morning i went to start it, and it took 3 tries. first time just sputtered and died, second time it hung on for a second then died, the third time it started up, idled a little rough, and as soon as i gave it a little bit of gas and let off it would drop to 500 rpms and die.

i plan on plugging the spark plugs tom. which are brand new and the wires which are fairly new to check them, but what else would give me this problem? fuel pump sounds healthy, car actually idles decently, could it be my fuel regulator or injectors? or would it be more ingition related like the opti?

 

Verify that you have proper fuel pressure with a fuel pressure gauge connected to the fuel rail.