Engine stalls at idle

[GMac99]

Hello, I'm new to this forum. Question I just removed and replaced a 5r55e in my 99 explorer Sport. I bought the tranny at a reputable recycler. FYI- The engine ran great before the install and now it will and will not idle. Especially when in gear. It's just fights for life and stalls. I have to give it gas to keep it running. Note: The is no warning engine light indicating DTC. I tried disconnecting the battery and reconnecting it. Does anyone have any thoughts. I know it could be something with the fuel delivery system but why now? The tranny works!

 

[Turdle]

If you hold throttle open a bit in gear does it idle?

Let's assume a coincidence happened, and since this repair is very inexpensive i would start by cleaning the IAC valve. This is the device which takes the place of your throttle input. it opens and closes to maintain idle speed. Cleaning the plunger and seal real well, while working the plunger back and forth will probably fix it.

How to: - IAC valve cleaning thread (w/pics)


does the check engine light turn off once the engine is running or does it remain illuminated, indicating a malfunction code? A stored code will also help troubleshoot this.

 

[GMac99]

When it's in gear I have to throttle a little bit to keep it running. And the check engine light does turn off when the engine is running. Thanks for your advice too.

 

[GMac99]

Went to NAPA auto and read the car for any DTC's. No codes were reported. I cleaned the IAC valve / still stalls. I'm at a loss here.