ok, ive replaced every sensor. on the truck
plenum replaced.
timing chain
water pump
radiator.
no vacuum leaks that i can find.
fuel pump replaced.


the truck will not idle. let go of the gas and it turns off.
I have no more ideas of what it can be.


The transmission is going bad. could this stop it from idling?

 

Have your battery and alt tested. These trucks will not hold idle with anything less than like 12.5 volts

 

charging system good.

the vacuum port on front of the trottle body what is that for, or is it just a extra port available.

 

If it is open, it needs a hose plugged into it.

 

ok its plugged, Any Ideas

 

That vac port is supposed to be hooked up to the evap system IIRC.

 

did you poke a wire through the little hole in the bottom of the IAC well on the back side of the throttle body to clean it out. it likes to get stopped up with gunk.

 

Yep +1 on that, purge valve/solenoid.

 

Here’s an odd one. My sister boyfriend who has no mechanical exp made me feel extremely stupid. While trying to start the truck. He just happens to say. Man have you looked at the idle screw. Well it wasn’t even touching the throttle, a quick drill and a few turns its running again. At about 700 rpms.

and the good news my throttle body received one hell of a good cleaning