I've got a "pump shot" question. I've got an '88 Camaro with a TBI 305. I couldn't get the ECU swap to work so I've "contracted out" the custom PROM burning to Ed Wright at Fast Chip. I was having serious problems with leaning out on quick throttle openings. I'm currently on my second chip from Ed and the condition has improved immensely. Sitting in Park or in Neutral it will rev fine, smoothly with no stumble, hesitation, or backfire. Under load however, it will stumble and hesitate badly for a second or two and then pull hard to the red-line. There isn't a huge cloud of black smoke behind me when I hit it so I don't think that it's too rich. Does this sound like an insufficient pump shot condition to you? Any help appreciated. I hope that this post is ok, topic wise, for this board...I apologize if it's not.

-Mark W.
'88 SC Camaro w/ 305 TBI

 

an easy way too tell if you have too much pump shot is to listen.. when you give it gas you will hear a loud HISSSSSSSSSS and thats al lthe extra fuel dumping in the motor.. if you punch it and all you hear is a real loud hiss and it stumbles then you might have too much pump shot but i doubt it since you say it revs fine in neutral. Im inclined to think you just need a little more

I also know why your ecm swap didnt work but you wont listen to me