350 tbi no major mods ran fine for what it is,just put another tranny in it and was driving it home and noticed when when I would level out on the throttle the engine sounded sick, but when I would accelerate it ran like it should.The next day the only way it would run was buy punching the throttle up and down, now it starts up and dies right away....crank die crank die crank die.....new IAC, TPS,EGR and sensor,fuel filt,o2 sens,tbi is clean as a whistle,coolant temp sens,temp sending unit, knock sens,vacc lines,......showing 32 psi on fuel press guage.......im a mechanic by trade and this is embarassing me...

 

If it's tbi then the fuel pressure is way too high!!!! You need to back that pressure down to no more than 13.

 

surprised to hear it will even start with that much fuel pressure.

 

How did you even manage to get the pressure that high? Ive never even heard of a tbi getting more than 20 psi.

 

well it is the fuel pump from my original tpi setup....car was 350 tpi.....dont ask... when the engine went i went tbi because it was already setup

 

as in the tbi engine was ready to stab, just changed harness'

 

Hehe, you need to change pumps, that TPI pump is supplying WAAAYYY too much for TBI. Even with an adjustable regulator I don't know if you could back the pressure off to what you need. But if you have one it might be worth a try.

 

Yeah, you need to change pumps. How come you just didnt swap the tpi onto the tbi engine? I think it would have been a lot simpler that way.

 

i sold the tpi setup..needed $$$ and i already had the tbi setup sitting there, was going to put it in my 72 gmc

 

oh yeah and I put an adjustable reg inline, played with it from anywhere between 15 and 25 and got nodda,and i did reset ecm and such, still crank die

 

You may have had an injector go T/U on you.

 

the injectors are supplying perfect cones at any given time

 

Try starting fluid or gas down the T/B. If you could make it stay running before by pumping the throttle and now it won't stay running at all, it has to be a fuel delivery problem. The fact that it fires off proves you have spark and at least some fuel, but it sounds like you are loosing fuel flow soon after startup.

 

same prob......if you give it throttle it will run....like s**t but you have to keep goosing it. For say I start it and give it enough juice to idle at 1000 it eventually dies, anything over it stays running, but like s**t. And when I say start it I am meaning someone turning key for me so I can be under the hood to play with the throttle.It dies so quickly even with me hanging in the window turning the key with one hand and my other just inchs away from the throttle body, but that half a second is not long enough to punch the lever to keep it running.

 

It has to be either over or under fueled. If you were running the injectors with the 32 psi fuel pressure, you may have damaged them to the extent that they are useless.

 

my 305 tbi runs at 11 psi a 350 should run no higher than 15 psi so fix that pump it will kill and tired ur engine soon