Stalling/Hesitation When cold

[Isaiahbarrett]

When my 1996 5.7 vortec is cold it will bog down and sometimes stall when put into drive or reverse. And until it’s reached operational temperature it has a 1-2 sec hesitation. When the engine is warm it is completely fine, no hesitation and no stalling. I have a summit racing 1065 cam. If someone could point me I the right direction I’d greatly appreciate it


Below are the parts/services that I have replaced/serviced in the last 6 months since owning the truck:

Fuel pump, tank and filter
Spider injections (GP Sorenson)
New TPS
Cleaned throttlebody
New spark plugs and wires
New distributor cap and rotor
New air filter
Cleaned EGR
New IAC valve/sensor (was stalling a lot before replacing this)
New Oxygen sensor (was throwing a code)
I have also tested the fuel pressure and it’s 59 PSI during idle and priming
New ignition control module

 

[Schurkey]

Connect a scan tool, check for codes, but more important--look at the data stream. Verify EVERY sensor especially the coolant temp. Verify the computer outputs--spark advance, IAC, EGR, etc.

Also look at the misfire counts for each cylinder, especially when it's running poorly. Maybe you can identify the problem cylinder(s).

 

[Astro]

When my 1996 5.7 vortec is cold it will bog down and sometimes stall when put into drive or reverse. And until it’s reached operational temperature it has a 1-2 sec hesitation. When the engine is warm it is completely fine, no hesitation and no stalling. I have a summit racing 1065 cam. If someone could point me I the right direction I’d greatly appreciate it


Below are the parts/services that I have replaced/serviced in the last 6 months since owning the truck:

Fuel pump, tank and filter
Spider injections (GP Sorenson)
New TPS
Cleaned throttlebody
New spark plugs and wires
New distributor cap and rotor
New air filter
Cleaned EGR
New IAC valve/sensor (was stalling a lot before replacing this)
New Oxygen sensor (was throwing a code)
I have also tested the fuel pressure and it’s 59 PSI during idle and priming
New ignition control module

Hey man, did you ever figure out what caused your issue? I've been having something similar happen to my 96. It hesitates when I give it any good amount of throttle when cold. After it warms up, it purrs.