Engine/Transmission (1994 - 1998) Need Help Truck Dies At Stop

[JimDavis]

Truck idles low in gear, it is a 98 all stock except gauges. Starts and idles at 800 rpm fine but when I put it in gear idle drops to 500 rpm and it wants to die. I scanned the computer and no codes changed the fuel filter and no help. It runs great the only problem is when you come to a stop it wants to die. I adjusted the idle and that helped some, it is now at 600 rpm in gear, but know it is like cruise control I can get to third gear without touching the gas pedal and it still didn't fix the problem. It happened suddenly also. Left home fine, drove 45 min stopped at the gas station and problem started when pulling in. Any ideas?

 

[MAleshire]

Specs call for setting the idle at 850 rpm with it in gear and the a/c on. You need to get a fuel pressure gauge on it to see if there is a fuel pressure problem. This would help rule out a problem with the lift pump and return valve, or somewhere else on the supply side. At a stop, do the rpms come back up if you take it out of gear and go to neutral? Long shot guess, if not a fuel pressure problem, do a search on TPS symptoms.

 

[jtwcummins]

When I had my 97 I had the same problem, more noticeable when a/c was on. Seemed better after warm up. Had to have 'curb or base' idle set twice to fix problem. You don't get good results using the dash tach, but can get close. Should idle at 850 in gear, auto, w/ a/c on. Had to get reset 2 summers then 9 yrs w/o any problem.

 

[JimDavis]

I have a fuel pressure gauge and it is reading at 23 psi. Yes at a stop if I shift into neutral rpms will go back up. I have adjusted the idle and it will not adjust above 700 rpm no matter how far I turn the screw. I did a voltage check on the TPS and readings are normal according to the manual.

 

[JimDavis]

And also with idle at 700 rpm it no longer wants to die instead it wants to take off like a rocket. Something still not right.

 

[Signal73]

do you have aftermarket governor springs in your truck?

 

[JimDavis]

No aftermarket governor springs

 

[Missouri Mule]

Are you sure the tach is correct?

 

[JimDavis]

Tach in truck reads the same as the Snap On computer.

 

[edgeman]

im guessing your truck is an auto. if it is there could be some toque converter problems. i know a person who has had the same problem and turned out to be something with the torque converter. just my 2 cents though.