I recently rebuild my 22RE. It has run fantastically for it's first 2000 miles of life. However, I have been having issues with a low idle when the truck begins to warm up. When I start the truck for the first time in a day it seems to idle just fine but after driving for five minutes the idle decreases steadily until it gets to the point where it wants to stall. If I start up the car and let it run for 10 minutes or so, turn it off, and try to start it up again it is very difficult to start and it seems that pumping the gas pedal is what it takes to get started. I have adjusted the TPS and checked for vaccuum leaks and have found no issues. Another note is when the truck first begins to idle, the voltage at the battery is approx. 14.3....once the electric fan kicks on it drops to about 13.8 or so. Not sure if the fan is causing the truck's idle to drop. Any ideas on what may be causing this? IAC? Would putting my EGR system back in help? Any thoughts/info on this would be really appreciated.

Turn up the idle air screw on the throttle body. Set it to 750-800 RPM once the engine is warmed up. An electric fan can pull the engine speed down at idle, just like power steering or A/C, both of which have idle-up circuits to bump the idle speed when they are on at idle.

I have turned the idle screw quite a bit...it only makes a minor difference once the truck heats up. The idle will sit at 1000 rpm when it first starts (as per engnbldr's reccomendation with his 261c cam) but then the idle will drop after a while even though the screw stays in the same place.

Is there any other way to adjust the idle?

What ignition timing are you running and how are you setting it (jumper in or out)?

Cold start idle is usually more than 1000 RPM, mine is usually 1200 or a bit higher. Maybe the throttle plate is set too far closed. Should be set fully closed then crank the stop screw in 1/4 turn. You said you tested the TPS, was the IDL-E2 setting within spec at idle? If not the engine/ECU will be "running really slow" instead of "idling". They are two different things.

Test #1 and #2 from your TPS adjustment page gave are reading infinite and 38.8 ohms repectively (test between IDL and E2 w/ a .85mm feeler gauge and a .57mm feeler gauge). I opened the throttle plate slightly and that solved the problem with the low idle even after test driving it for a bit so I think that is solved. I shut it down...waited about a minute and tried to restart it and it took several cranks and me pumping the pedal again to get it going. Could that be some sort of fuel issue? My pressure gauge is reading about 40 or so PSI before I start the vehicle.

BTW- I appreciate all of the help! <img src="/forums/images/graemlins/cheers.gif" alt="" />