1995 5.7 TBI running poor

[mbb]

Need help. Didnt drive my '95 z71 with 5.7 L for a few wks, It was fine the last time I drove it. The next time I did it ran like crap and has since. It hesitates and stumbles and bucks on acceleration under load. If I rev the throttle at idle, I can tell a slight hesitation there too. Its undriveable like this. Changed fuel filter even though I didnt really think it would be culprit. It had no effect. Changes plugs, no effect. compression check looked OK at ~165-170 psi for all cyls by my guage. The engine service light is working, but has not come on to signal any codes . I filled tank with new gas, no change either. checked PCV, clear and clean. what could cause this? Bad fuel pressure or faulty regulator? Or ignition problem?

[nusch]

Check the egr valve and make sure that is not stuck open a little and if that is fine I would check the ignition coil and pick-up coil.

[TopDogg]

I just bought an 89 that is doing the same thing. So if you figure it out let me know.

[TopDogg]

Hey MBB , in the previous reply I said my truck was doing the same thing. I checked my timing and it was way off. Distributor clamp was loose. Runs much better now.

I bought the truck running bad. Lucky me it cost nothing to fix.

[mbb]

replace distributor cap and rotor ...no improvement. Put some B12 chemtool in gas tank, voila. Problem gone within a few miles. Looks like must have been sticking injector. Since Ive done the rest of the tuneup timing is next anyway.