Jeeplover99

I have a 1999 Grand Cherokee Laredo 4.0L which was running perfectly
until tonight. I went to start it but it wouldn't turn over. I thought
maybe I hit the gas pedal when I tried turning it over and flooded it
or something. I then tried starting it holding the gas pedal to the
floor and then quickly letting it off if it turned over, that worked,
it started right up but would just stall when it hit low rpm idle
speed. If I held my foot lightly on the pedal it ran smooth at 1000 rpm
but the second I let it off it would stall. What could the issue be???

j4bs4209333

Does it only stall out in N or P? Have you tried to throw it in drive before it stalls? I've had 2 of the 4.0L Jeeps that have both done the same thing. One of them would stall in P or N and it would chug real low in D or R. The other would stall in P or N but would stall quicker in D and R. Both of them just had plugged up IAC valves. Take it off and spray it with carb cleaner until it stops pouring the black carbon out. That fixed both my 4.0's.

Bustedback

Sounds like a failing idle air control motor.

Jeeplover99

Thanks so much that worked great! Thanks
For the help

dTack

But that don't really fix the problem just goes around it and in my experience that causes more problems. Have you hooked it up to a code reader?