This is on a 91 T/A, 305 TPI, 5spd. While merging into traffic I got on it relatively hard and when I let up on gas, essentially coasting (no load), car started to shutter. As soon as I put any load on it either accelerating or decelerating it smoothed out. Car idled fine at stops but everytime I got into a no load condition it shuttered badly. No engine check light and no codes were set. The next day everything is fine but I wary of getting on it again. Any ideas of what to start checking?

 

I have an 1989 firebird that just recently (got car back from local garage) with same symptoms except worse. From idle, everyonce inawhile when i accelerate, the car shutters as if it wants to stall (service engine light comes on, radio cuts out), but then will go away once i let off the gas. After that it accelerates fine. Local garage guy is suspecting the computer. If anyone else has had this same problem, please let me know!!! Maybe bad tank of gas?

Greg

 

Maybe a dying fuel pump, or clogged filter.

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'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
3" Hooker CatBack w/Aero Chamber muffler
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
3:73 Posi
Rebuilt 700R4
B&M Megashifter, 5" Autometer Tach w/shift lite

 

Check:
-Dying fuel pump
-Clogged fuel filter
-*Messed up timing/Timing Chain*
-Clogged Air Filter/Intake
-Fouled Spark Plugs / Carbon Build up

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1989 Chevrolet Camaro IROC-Z
L98 - 350c.i. TPI, rebuilt 700R4 auto w/shift kit, Dual catalyst Monza PaceSetter Cat-Back, SLP 1 5/8 Coated Headers, 3.23 Posi rear, Hypertech chip with 160stat, MSD 6A, Under-Drive pulleys, AFPR, K&N's, !Air Box w/ Ram Air, moddified MAF, !TB Coolant, Spohn Dual Cat SubFrame Connectors, Alarm, Keyless entry, remote starter, 92 Z28 AeroWing, Brand New Paint (6/21/01)

Future: ZZ4 TPI w/EGR, T56, 3.42 or 3.73, Spohn strut tower brace and LCA's, Accell 24# injectors

1989 Chevrolet Celebrity Eurosport <--DEAD AS OF 9/20/01
2.8 MPFI, no mods
225,000 miles and still ticking!

More info and pics on my webpage:http://go.to/iroc-z

AOL IMer: GPA 0point0

 

Polarsmurf ... in your case if your Check Engine light came on, I think this means your computer should have stored a code to help with diagnosis. Do you know what code has been set?

Thanks to others with their suggestions ... plugs and air filter are good and I need a way to start isolating others. I'm not sure how some of the others would cause my problem because car accelerates just fine ... its after I get off it and try to just drive at a steady speed without any load on engine ... any insight to how these might fail in this way would be great. Today I drove it easy and everything was fine.

 

At my local garage, the mechanic had it hooked to the computer and got the car to sputter. Now the computer puts out NO codes, which is why he believes it might be a computer problem. Its odd, because it accelerates just fine sometimes, and nearly stalls/sputters the other time. Thank you very much for all the information and help. I'm going to check out what you peeps suggested earlier.


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1989 firebird formula

 

Well I've got on it a few more times and it hasn't missed a beat ... if it does act up and gives up any additional secrets or I solve it I'll post the details.