Hi all;

The title pretty much says it..it surges up and down when warming up and also when I accelerate going down the road. Could this be that IAC, or maybe a fuel pump relay if there is such a thing? Sometimes when I slow down the engine rpm drops down so low it dies on me. So far I have replaced the Map sensor and egr valve.

1988 Dodge Ram Van,, 5.2 / 318

 

Use a strong flashlight and make sure the fuel injectors are firing in unison and equal spray patterns.

 

The IAC is only a factor at idle, hence the name Idle Air Control valve.

Does the surging stop after the engine is fully warmed up?

 

After that what should I try next? I should mention too that is is the TBI type fuel system. Can the injectors be replaced if bad? Thanks

 

Actually yes..it does seem to pull out of the it. Well at idle at least it stops dying..still acts goofy on acceleration though..sometimes however after awhile it seems to pull out f that until I park..i/e grocery store..but then does it again on the way home.

Got a brake issue too..should I make a new thread for that? If not..here is the problem..they make a knocking sound..not when I brake but while just free wheeling..if I just barely touch the brake pedal, it stops. Just replaced the pads and the front brake lines..per advice from someone here..because they were locking up. No more locking up now..just that knocking noise.

 

Change the 2-wire coolant temperature sensor. It's probably sending the wrong reading to the PCM which in turn affects the air/fuel mixture.

The 1-wire CTS is for the temperature gauge on the dash and has no affect on the PCM.

As to the brakes, it sounds like a damaged rotor. Did you have them resurfaced when you replaced the pads?

 

That was it! I replaced the coolant temp sensor and it stopped surging..as a bonus no more check engine light..thanks a ton alloro

landyacht318, I may replace those injectors, and a few other odds and end..like the O2 sensor also..after all they are old..cant hurt none either

 

Knowing the CEL was on was a rather important omission.

What about the brake rotors?

 

Yeah the engine light code (key dance)..said it was the map sensor..which I replaced..but still would not go off..it did once I replaced that temp sensor..and never came back on

Not sue on those yet..someone said try replacing that anti rattle kit first..it didnt do this until I replaced that brake line..and the pads..used the old anti rattle stuff back..