My documented TBI-to-Vortec 350 conversion!

[Horns]

Check fuel pressure.

~Via Mobile \,,/

 

[jdyates]

Check fuel pressure.

~Via Mobile \,,/

I still need to get the iroc pump in, but the TBI fuel pump should be enough to power it outaide of WOT. It's putting out 11psi, and still did it with the old motor.

 

[94Sierra4x4]

I still need to get the iroc pump in, but the TBI fuel pump should be enough to power it outaide of WOT. It's putting out 11psi, and still did it with the old motor.

Should have changed out that pump already for the iroc one.. Eliminate the variables..
Your getting it up to what, 1/4 throttle and it bogs out?

 

[jdyates]

Should have changed out that pump already for the iroc one.. Eliminate the variables..
Your getting it up to what, 1/4 throttle and it bogs out?

Yeah, bogs and shuts off. I see your point about changing it now, i just dont think fuel pressure is an issue since it was within spec with the tbi heads, and still did it. So it's gotta be something i swapped over. Gonna grab a new MAP in a bit and see if that helps. If not, im working towards ECM or wiring problems.

Definitely agree, though, need to get the new pump in.

 

[whatif3387]

Your deff not getting enough fuel the vortec heads make alot more power.Depending on which 5.7 injectors your running you will at least need 20 psi maybe more.

 

[jdyates]

Yeah that's what they told me over at gearhead. Anywho, went with a new MAP sensor, seems to run a tiny bit better, but still cuts out.

Trying to get ahold of Mark for the chip, PM'd him with my contact info, anxious to hear back. Then the fuel pump should be in by this weekend.

At this point, I'm positive you guys are right about it not getting enough fuel pressure. I think the heads are trying to swallow waaaaaay more fuel than the injectors are allowing, at much less throttle than I originally thought.

Updates soon!

 

[Horns]

You're getting 11PSI right now with the stock pump? It should idle fine, but that's barley enough for a stock TBI.

 

[94Sierra4x4]

Yeah that's what they told me over at gearhead. Anywho, went with a new MAP sensor, seems to run a tiny bit better, but still cuts out.

Trying to get ahold of Mark for the chip, PM'd him with my contact info, anxious to hear back. Then the fuel pump should be in by this weekend.

At this point, I'm positive you guys are right about it not getting enough fuel pressure. I think the heads are trying to swallow waaaaaay more fuel than the injectors are allowing, at much less throttle than I originally thought.

Updates soon!

Yeah man. Not swalling more, just burning it faster, I would assume

You're getting 11PSI right now with the stock pump? It should idle fine, but that's barley enough for a stock TBI.

I've read a few times that these TBIs barely push enough fuel to run past 4k RPM

 

[jdyates]

Haha good to know. Just got the news that I got accepted into a school 350mi away, so i need to get the pump done soon, cause I'm driving up there Oct. 16.

 

[Murd450]

Bump for updates !

I want to know your power differance ? I just picked up a vortec 350 with 15000 mi on it and was just thinking about throwing the carbed intake with the tbody adapter right in my truck . I bought it to take apart and build a race motor but can't bring my self to cut up such a low mi engine !