it's story time...

my brother often borrows my mom's 96 xj (4.0 with auto trans). he decided to take it wheeling. he got busted as he brought it home with a bent up back bumper and wet carpets. he claims he backed into a pole and spilled a drink but after some inspection it's pretty clear he got stuck and had to be pulled out. the bottom of the motor and vehicle have mud all over them and the carpets were soaked so he clearly got it stuck pretty good. now the thing idles real rough once it reaches normal op temp and even stalls on occasion. no cel.

after doing some research, I'm thinking it could be the cps. my dad is pretty set on it being the ignition coil. the mud is on the oil pan pretty good but not much higher so I don't think he completely submerged it.

any ideas on what we should check? anyone know of a way to test the cps? I found a thread saying it could be doused in cold water once it the vehicle reaches temp and starts running bad.

thanks

 

Take a look at the upstream and downstream O2S'. See if they are caked with mud. There are breather holes in the side of the O2S body and if they get blocked it will affect the operation of the O2S. Also, check the wiring to the downstream O2S and see if it tore up.

 

duh! didn't even think about the o2 sensors. I'll give them a good look over. thanks for the quick reply.

 

both o2 sensors were replaced post wheeling. the downstream was damaged so my dad replaced both for good measure. didn't make a difference.

 

Normally they wont. Doubt it's the cps either. Check all the distributer. Inspect the radiator real well for clogged fins. I would replace the spark plugs also.

Air filter and oil change goes without saying.

 

How does the top of the engine look. Does it look like it was submerged (LOL). I mean, is there signs of mud or water on the motor.

The Throttle Position Sensor hates water. You may want to pull it and see there's any sign of water intrusion. Or replace it outright. Don't use a BWD TPS however.

 

no signs of full submersion but it wouldn't hurt to pull the tps anyway and clean it up. what brand tps are okay aside from mopar? I have a bwd in my Cherokee and it's definitely a little funky. the throttle can be weird when you let off. there's slight hesitation in the motor realizing you let off the gas so yes, def avoid bwd lol

 

I haven't checked NAPA to see if they have an Echlin TPS (Too lazy to look). I use Mopar TPS ONLY.