so i rebuilt the motor in my 93 silverado it is a 5.7L bored .30 over flat top pistons, gm performance intake, headers, brand new heads. after i re built ...

so i rebuilt the motor in my 93 silverado it is a 5.7L bored .30 over flat top pistons, gm performance intake, headers, brand new heads. after i re built it i could not get the timing set so i took it to a local shop he hooked it up to a computer and said the map sensor was stuck open so he replaced it. and did not help it run any better. you could see the throttle body was dumping way to much fuel so he switched out the holley TB for a stock one helped a little bit but still doesn't run good. so he adjusted the valves set the timing etc and now it doesn't want to get up and go? he said the fuel pressure is supposed to be around 10-14 PSI he said mine is 9-10. does anyone have any ideas? we also switched out the computers in the truck for another one and did not make a difference.

Whew! Lots of stuff going on here. Ok, I'll bite. The valves are adjusted too tight. A compression check would reveal this.

phew thats alot of gravy, when my truck was only putting out 50 pounds when it needs 53 PSI it wouldnt start but it ran fine...clueless man could be a fuel pump but i have no diea. was the motor you switched from EFI? or was it carbuerated?

that i have no idea....... i just bought the truck it is a 93 but all the parts i needed for the motor is a 96 so i really don't know what the motor is lol. and about the valves being tight the gm mechanic adjusted them

It would have been a throttle body unless someone switched it. The throttle body was used from '88 - '95

yep and it has a holley throttle body. it is dumping to much gas in the intake it is pouring into it so iam looking for a stock one 93-95 will work....

Sounds like the tps,throttle positioning sensor, mine wouldn't start without berrymans but then ran fine. Is it shifting ok, if not definitely the tps

i figured out the problem the motor is a 98 350 Vortech with the 88-95 TB on it that's why its running funny lol

That could cause it.

yea not supposed to put anything over a 95 in it. i talked to the person that did the motor swap he said they been dealing with the hesitation ever since they dropped that motor in........ i don't have to worry about the truck anymore i found a buyer for it lol gets really old spending $100 every week on it