On my 98 5.9 V8 gasser.. im having issues , Not sure what the word is for this, but ever since i replaced the worn out battery terminals the torque convertor has been acting wierd. When I drive to 40mph it locks like it always does, and stays locked when I let off the gas at 48 mph or under it will coast freely like its supposed too, but if im at 50mph or higher and let off the gas the engine RPM surge down quickly dropping about 3-400 rpm and the vehicle pulls itself back like its engine braking.

It never used to do this before, i cant drive on the freeway or above 50mph anymore and just coast without it engine braking and slowing down really fast.. It isnt dropping out of overdrive i tried turning the button on and when I do it engine brakes really hard and i can feel it downshifting so its deff not OD.. Sometimes will coast normally when i let off the gas at 50mph other time it drops rpm's like i mentioned engine brakes but then the rpms go back up again and itll coast for a second or 2 then rpms drop again.. Its like the torque convertor is unlocking and locking when im off the gas pedal.

Again its never done this before until i changed battery terminals. My old ones were so worn out they were cracked, and not holding onto the battery very well anymore.. I cut them off remove some insulation on the wires cleaned up the copper to shiny and put them in the new battery terminals and bolted it down and put it on the battery.

I just now went out took the wires off and cleaned them up again and positioned them better on the terminal but it doesnt seem to have any effect..

Any idea whats going on here ? I've dug up that it could be a grounding issue, but i dunno.. what should I do ?

 

PCM grounds circuits to engage O/D, and TCC. If TCC is not releasing..... something is definitely up. Try taking it for drive, run it up to 55, let off the gas, and lightly step on the brake. TCC should disengage. Does it??

 

How would I tell if it disengages tho because if i let off the gas pedal at 55 the rpm fluctaute wildly like they drop 400 rpm and the engine bogs down, and then it "releases" and the rpms go back up and it will coast normally again. But then itll bog down dropping rpms, it just keeps fluctating.

WHen its below 50mph tho its coasts fine. I know when im on the gas and i press the brake pedal it will unlock itself and when i let off the brake it will relock again "while im still on the gas"

I'll try what you said tho and let off the gas and tap the brake lightly and see if it surges and bogs down. Because like I said this never happend until i replaced the old terminals. Better yet i will take a video of it so you can see how the rpm's are reacting.

 

I wonder if your Throttle position sensor is going... may not hurt to test that as well.

 

You may be right, i think both the TPS and IAC are bad.. Sometimes when im idle my rpm go up to like 1500 i have to turn the Jeep off and turn it back on.. Other time it will go up and down and up and down..

I always suspected the TPS and IAC were bad... I'll replace them both with a mopar one when i get the cash.. I tried those cheap $20 ones at auto parts store and they just give me check engine lights and cause my Jeep to not even start..

When making my video just now.. the RPM drop only happend once in this video.. after that it was fine.. I did wiggle wires earlier today, and i did unplug my TPS and plug it back in as well.. So maybe your right its the TPS.

I'll upload the video when its ready on youtube.

 

Did you disconnect the battery when you changed sensors?

 

Yea I did. The cheapo sensors from the auto parts store suck.. I tried 2 diff brands

 

Denso or NTK...These Rams don't seem to like the others I hear.

Personally, I would not mix and match these. Don't know if it would make a difference, but I like to play safe.

 

The ones i bought was a NTK TPS i think, and that one caused a check engine light after 2 days and it wouldnt start until i unplugged it and put it back in.. wierd.. The other brand was a Bosh "spelling" one and it did the same thing.. So i had to put my old one back in. The dealership ones are like $140 each so thats why i havent gotten them yet, i just dont have the funds lol.

 

Here is the video, its really good quality, but it seems my phone doesnt record very good sound, so you might want to turn the volume down or off, when im driving like 40-60mph lol the wind noise on the vehicle seems to be picked up pretty good on the speakers lol.

If you skip to 2:25 and watch as i pickup speed to 55ish mph and let off the gas pedal you will see the rpms go from like 1800 to about 1300 and it starts to pull itself back engine braking. Thats what it has been doing.. However the rest of the video it seemed to be fine you dont have to watch the whole video if you dont want just watch that part at least.. The rest of the video is me pressing on the brake while on the gas, and not on the gas, and me going from a stop to WOT. which is at 9:28 and at 10:10