3400 cuts out when gas pedal pressed

[patgizz]

my 3400 is doing something goofy. it idles beautifully and smooth. when in park if i push the gas pedal it cuts out for a second and then pick up and revs perfect. if i'm in gear and try to do the same, it just cuts out and quits running. after it does this it takes forever to restart.

injectors ohm out good, fuel pressure is spot on 43psi.

only thing i can think of related to this is the throttle position sensor???

i'm gonna pull my hair out if i can't figure this out, cause otherwise it runs so nice and smooth, and is ready to drive.

edit: i was just out messing with it. i started it up(it starts right up when cold). when its cold, for like the first 20 seconds, i can nail the gas as hard as i want and it jumps right up to the limiter with perfect throttle response. then as soon as it starts getting warm i get the above problem with it cutting out. i changed out the TPS and it didnt help.

[Guest]

RE: 3400 cuts out when gas pedal pressed

Coolant sensor maybe?

[bszopi]

RE: 3400 cuts out when gas pedal pressed

Or perhaps O2 sensor. That's the only thing I can think of that really takes effect not until it goes into closed loop.

[imported_germ]

Re: RE: 3400 cuts out when gas pedal pressed

Or perhaps O2 sensor. That's the only thing I can think of that really takes effect not until it goes into closed loop.

[patgizz]

RE: Re: RE: 3400 cuts out when gas pedal pressed

installed new known good ones(cts and o2). changed tps.

no change. its only within the first 20 seconds that revs fine, then after that it cuts out. so nowhere near closed loop yet.

for the hell of it i tossed in 2# larger injectors and that didnt change anything.

[SappySE107]

RE: Re: RE: 3400 cuts out when gas pedal pressed

scan tool time:P Sounds like the IAC is too closed or something, or its the computer progam not liking the new engine.

[patgizz]

RE: Re: RE: 3400 cuts out when gas pedal pressed

ya i need to get that laptop from you... doh! i was hoping this thing would run well enough to make it out because everything else i have gets under 15mpg on the highway. i know that if i didnt anticipate it running right, and bought that damn temp tag last week, it would have been fine... shot myself in the foot.

[torq455]

RE: Re: RE: 3400 cuts out when gas pedal pressed

maybe fuel pump vol? did you do the psi test when revving?