'92 5.7 starts, then stalls when in gear...

[Randy Curran]

Like the title says. I just bought the truck and it test drove fine but on the way home it would stall at every stop. We went through obvious things and we can tell the previous owner had the same problem (which he failed to tell me of course) because some of the vacuum lines were replaced and the IAC was replaced.

We narrowed it down to a fuel pump (it was a guess because no one around here had the fitting for a TBI setup on the fuel pressure gauge). Well we changed it out (had to cut a hole in the bed because nothing was coming loose, the bed or the tank).

Same problem. HELP!

 

[Jrgunn5150]

Does it stall when you hit the brakes? Or just won't idle in gear?

 

[Dylan1991_1500]

I am assuming this is auto?

 

[df2x4]

Have you double checked that there's no vacuum leaks anywhere?

My trucks are Vortecs but I had this exact same issue with my V6, would stall every time I tried to idle at a stop light. Vacuum leak was the culprit.

 

[Randy Curran]

Yep an auto, 4l80. It stalls after you've hit the brakes.

 

[Randy Curran]

Checked the TPS, MAP, ECT, replaced the cap and rotor (the rotor was really gunked up). Still same thing. It idles in park and neutral no problem. Give it some gas and it starts to stumble. No idea!

 

[Scottydc]

What are the chances that the torque converter is not unlocking on the TCC or that it's stall is coming in too low for some reason?

 

[Randy Curran]

That's what we've been thinking too. Any ideas on how to check it?

 

[Jrgunn5150]

Yep an auto, 4l80. It stalls after you've hit the brakes.

Plug the vacuum port to the brake booster and try it.

 

[Justin S]

Sounds like torque converter, try popping it in neutral when you are coming to a stop and see if it does the same thing.