93' 5.7 seirra stalls when accelerating

[lowedawg20]

I have a 93' seirra with a 5.7l v8. When I start to accelarate it cuts out. Once the rpms get up it runs find. I have went through it. Fuel psi good. No codes. It has a Holley throttle body on it. Do I have to adjust anything for the Holley?

[J-Ri]

Did it act up after installing the Holley TB? If so, I would contact them. The TPS may be different than stock.

[2000CAYukon]

If the TPS is correct, check to see if the MAP is connected to right port or acceleration will not be correct (assuming everything else is operating properly). The MAP needs manifold vacuum to work properly.

//2000CAYukon

[lowedawg20]

The holley throttle body was already on it when I bought the truck. Just about all the sensors are new. I just change out the egr valve and it helped a little. It still stalls when I floor it though.

[J-Ri]

New doesn't always mean good. I've had several new parts that were bad.

Also check the fuel pressure, if the pump volume is low, sometimes the increased injector pulse width can drop the pressure enough to make the engine stall.

[lowedawg20]

Just changed out the fuel pump because of low psi. Have had the truck in the shop for a while. Mech said it might be the ECM. ANy way to check?

[J-Ri]

You would have to figure out whether it loses fuel pressure, injector command, or spark when it dies. Then check the PCM output that controls whichever it loses. Then check the input the ECM uses to decide whether to command (part X) on. This is a situation where I might actually suggest swaping it for a salvaged one. It would be a lot easier than diagnosing it properly, and probably not too expensive.

Is the fuel pressure where it should be now? Did you chack the MAP sensor?

[lowedawg20]

I keep getting a Code 35 Idle Air Control. I changed out the IAC valve but still not right. How do I check the valve and harness for proper function?