Engine/Transmission (1998.5 - 2002) Occasional Erratic Idle

[wcjp]

A friend has a 99' 24valve 5spd with Fass, Edge Drag Comp and 4" exhaust. Sometimes at idle the engine rpm will drop as if it's going to die. He'll give it some fuel and engine will recover as if nothing is wrong. As far as I know it has no codes stored. Box is typically left on 2. He borrowed my temperature gun. Cylinder 1 at the exhaust manifold was 195deg F. Cylinder's 2-6 measured 235deg F. Any ideas?

 

[SDeno]

check the lift pump pressure and make sure it is even working. truck will still run even with lift pump not working at all. for a while that is. then it will just stop and you are done till the tow truck gets there. mine ran for 6 months with no lift pump. also check the fuel filter or just replace it. hope this helps.

 

[wcjp]

He's running the Fass. Fuel pressure is a constant 15psi. Recently replaced the fuel filter to no affect. With the comp on 5x5, pressure can drop to 11 or 12psi.

 

[RAJohnson]

VP

 

[C.Solomon]

Mine did that when I had a Edge comp box go bad.

It would do it with the box on or off.



When my comp went bad it had all the symtoms of a bad VP. When I uphooked the comp it ran fine.



I'm not saying its not the VP but uphook the Comp and see what happens.

 

[RAJohnson]

Mine did that when I had a Edge comp box go bad.

It would do it with the box on or off.



When my comp went bad it had all the symtoms of a bad VP. When I uphooked the comp it ran fine.



I'm not saying its not the VP but uphook the Comp and see what happens.

Good point

 

[2-ND TIME]

Erratic idle

The cylinder temps are alot warmer then mine when I've measured mine.