98 Ram 1500 4x4, unmodified

I have been running into an issue similar to the one noted at https://dodgeforum.com/m_1199787/mpage_2/key_/tm.htm

Let me say what happened: The initial problem was when I went through a car wash (with undercarriage wash) about five weeks ago. As soon as I exited I could tell there was a problem. When I accelerated it would accelerate really roughly and hesitate quite a bit. I pulled into a lot and shut it down for 15 minutes. I then restarted it with no problem. When I pulled onto the main road and accelerated (not hard and well below normal acceleration) it got much worse and I got a CEL. Turned it off and it came back with no CEL and just ran rough. Over the next couple hours as I drove it I noticed one key thing: If I put it into park the rpms would surge and it appeared to be running below normal RPM levels. The next day it was fine.

The same thing happened last night, but I did not have time to mess with it and it had a short drive. This time it happened while leaving a wet parking lot. I had driven no more than 100 yards before it started showing clearly. I had driven through one small puddle maybe 1-2 inches deep at the most.

A couple of things that may help: The cat was replaced in February along with the O2 sensor. I managed to drop in at Checker this evening and they were showing a code (but no CEL) for the O2 sensor. They could not clear it and told me to go to a place a couple blocks away. I did and they were showing no codes at all. I am going to hose down the cat tomorrow (assuming no snow) and see if that does anything, but it does not seem like it would be the issue.

Now, from what I can tell the probable causes are as follows:
1) O2 sensor - From my limited understanding it should not be causing this but that code was (briefly) showing
2) Spark plugs - I don't see how these would be getting wet the second time this happened because it was running fine before it was parked for six hours in the lot. The plugs and wires are ~2-3 years old (the plugs may be a bit newer, not sure).
3) Distributor - No clue about this.
4) TB or related sensors - I cleaned this the week after it first happened and it was still fairly clean.


So assuming it is not the O2 sensor (which my spraying the cat with a hose should be a definitive test of), what should I be checking next?

 

i had the same thing happen in the carwas and once when i drove through a swamp. a mechanic told me that it was probly the belt spinning water onto the alternator, but idk it doesnt do it all the time.

 

The fact that it happened driving out of the parking lot is what worries me more. I might just ignore it otherwise but if it is going to do this with even a small amount of water I am a bit concerned.

 

here's what i would do. buy a couple tubes of di-electric grease at the local parts store or walmart. its conductive. crawl around under the hood and under the truck, gently disconnect each electrical connector and put a small dab on each electrical contact. not much, don't go overboard, just a little dab, and reconnect it. do a couple, re-crank the truck and make sure its still running ok. don't do 10 at a time, cause if you mess up one, you won't know where to start troubleshooting. this might/might not help. certainly won't hurt, unless you break the electrical connectors. be gentle and undestand how they come apart. on those with the red tab, you slide the red tab back, away from the plug, and they squeeze them (i think). for those that are sticky, it helps to slide a flat screwdriver between the connections and very gently twist it. while squeezing the proper place.

inspect all wiring while you are there, looking for places where it may be rubbing something. if you find something suspect, wrap some vac hose, black tape, or wire loom around it.

if you can get a CEL, do the key on-off-on-off-on thing to get the code (if you have digital odometer), or visit local auto parts store to read the code.

my first guess might be the "impossible to get to" crank position sensor on the back of the block, up high, passenger side. you can do a seach here for some pics.

 

+1 on the crank position sensor. Also the camshaft position sensor connection could cause this problem. That is the one that got me. Use the di-electric grease on them first.

 

i would start with a spray bottle of water and start the truck and start spraying all your plug wires and see if it starts acting up then if that checked out start spraying whatever else it is that you suspect was causing it like the crankshaft sensor and whatnot .

 

dielectric grease was made by god himself! if the truck manufacturers used it from the factory then we wouldnt hve to deal with electrical problems as much as we sadly do. use it liberally. someone on here said it was conductive, mustve been a typo because, dielectric grease is made specificaly for making water and corrosion-resistant connections inside and on electrical connectors. and i definitely agree with the person who mentioned the spray bottle trick. but without a doubt, put the dielectric grease on and inside of all your connections. it will save you a million and a half headaches.

 

Well I sprayed down both sensors around the cat and also sprayed all the spark plugs to no signigicant effect (that I could tell). Will do the same but with more water tomorrow to be sure.


Also, how hard should the spark plugs to be removed? I tried to pull one but was not able to.

 

sometimes the boots get stuck on the spark plugs, be careful not to break them or you'll have to spend more money. As for the sparkplugs themselves, they should not be that hard to remove, hopefully you didn't get an idiot that torqued the hell out of them, if you are going to remove them all use some anti-sieze on them, it will make removing them in the future much easier.