Engine/Transmission (1994 - 1998) Idle problem

[JKouzez]

Ok guys I did a search and found this is a common problem mine is doing this, the idle is surging about 100 rpm up and down, truck wont start unless i tap the throttle as soon as i do it cranks right up, if i let off while driving sometimes it dies so i have to hold the brake and gas. fuel filter was changed about 5k ago, gsk was installed over a year ago, idle is at 750 according to tach in drive with a/c on.

What do you guys think low fuel pressure (i dont have a gauge), bad overflow valve truck has 102,700 miles, or im thinking bad return line. Let me know thanks alot.

 

[Jschafer]

If the return line has not been changed it is probably time.

On my truck when something is leaking (most of the time anymore ) it shows up on the tailgate. If the return line is bad it will cause what you are describing and they will go bad it is not if but WHEN

Joe

 

[Joe G.]

It is probably the fuel hoses like Jashafer says. If not it may be another air leak or an overflow valve problem. Check fittings, pre-filter, fuel heater electrical connection, and the short hose between the pre-filter and the lift pump.

 

[Sheepherderspecial]

sort of same problem here

I sort of have the same problem. usually i notice it when i back into my shop. There is about a 3 inch tall jump up to the concrete, and i have to barely goose the throttle to get it over that. if i let off quick it will die, especially when the engine is cold. i also noticed it the other day when the motor was still cold. i was holding it about 1100 in drive for about 30 sec or so and it died. started right back up though. has me scratching my head.