Car was running great, then one day after the engine got a bit hot, after starting it, it would buck hard when I hit the gas, I barely made it home - as if its not getting fuel. Now, it bucks when cold, takes awhile just to get up to 50MPH. Once engine warms up its much better and I can drive it on the highway fine. When cold, it stalls during startup.

Replaced cap& rotor and ignition coil, will do plugs and wires next. Fuel Pressure at rail is 40 PSI (normal). Need to check EGR. Unfortunately, it could be a *million* things like vacuum related, or electronic related like pick-up coil or ECM in the distributor, or a bad sensor, or fuel related like
pump, filter, pressure regulator, and/or injectors. Tach is reading fine, there are no unusual noises either.

Anyone have this problem and what did you do to fix it? Any advice is helpful.

(In the past I've had wierd problems like "would not start" and to fix that I replaced the temp sensor (it always read "warm" and the computer did not supply the required "richness" to get it to start).

Thanks, --Alex

 

Does it idle well? How's the timing? I literally parked my S10 before class, was running fine. Came out a few hours later, sounded like the engine was gonna come right out from under the hood it was bucking so bad. Turned out to be a bad dizzy, and the timing was way off.

 

you might want to check all sensors, then injectors

www.southbayfuelinjectors.com