97 dodge ram, 318 5spd, 180k, 2wd. All stock, no mods.

Ok the truck started running very rough after my father made a trip back from Georgia, we are in South Carolina. He has been driving the truck out of state quite frequently. Once this problem came up he brought the truck to me. Ive spent quite a few hours on it and i am miffed.

The truck will run rough, intermittently. You drive down the road, it runs fine, stop at a stop light and sit for a second then the RPMS drop, the truck shakes and you can hear a loud sucking noise. You have to blip the gas to keep it from doing this. If you let it go it will run like this and the truck will go to the verge of stalling, the oil light will come on (near stalling) and then the rpms will shoot back up, then it will work its way back down again. It smells like gas is being poured in by the gallon, and the sucking noise gets worse the lower the rpms go. Also when you take off from the light the truck will hit a wall, you push the gas but the truck wont go, it bogs down badly, but once it gets through that spot it will run fine. It wont have these problems sometimes. Sometimes i stop at a stop sign and the truck will be fine, and it will take off fine. Then other times it will start running like crap. If i let it sit long enough running the problem will come back.

Ok, then i hooked up my Solus to see what was going on. Im getting NO ENGINE CODES. I read my data display on the Solus and everything seems to be working fine. The o2s are reading correctly, the IAC is adjusting properly, the TPS is working properly, yada yada. When it starts to run like crap at idle everything goes nuts. The IAC jumps up and tries to adjust to a WOT condition (where the sucking noise is coming from) and the o2's start to read extremely high. The fuel adaptives go WAY into the negative, (trying to adjust to a rich or lean condition?)

I pulled off the TB, removed the tps, map, and IAC. Cleaned the TB very well, got all of the crud out of the IAC circuit. I then cleaned off the IAC and reinstalled all of the other sensors. Problem is still there, no change. What is going on? All of my sensors are in proper working order per my Solus. Ive got no vacuum leaks. Something is triggering this condition, and everything is trying compensate. I just cant see the problem.

Any Ideas? ANYTHING?

*EDIT* 9/22/08 PROBLEM SOLVED, SEE PAGE 4.

 

did you reset the PCM , If not try that and see if it comes back.. disconect the neg for a couple min...

 

plenum leak ,look in the down in the throttle body for a pool of oil. big problem with high milage dodge trucks

 

Sounds like the fuel pump is dying

 

Other than the sucking sound, you did not mention if you checked for vacuum leaks. Maybe that's why your O2 is reading high? Intake gasket leak maybe?

 

I wanted to say fuel pump as well. When you turn the key to the "ON" position, but not quite to "START" yet, do you hear a mechanical whine from behind the driver's position? Should be the fuel pump getting ready to do its thing.

 

Ive reset it with my solus several times. And ive disconnected the battery once or twice. No effect.

 

Ill check that out.

 

I did check for vacuum leaks. I fixed one for the EGR, but that had no effect on the problem. No other vacuum leaks that i can tell, but i will check again.

 

The fuel pump was replaced 2 years ago by a dodge dealer. I know that means nothing. When it starts running rough ill see if i can check the voltage going to the pump. and check fuel pressure.