Alright, I've acquired myself a used truck at a STEAL of a price. The particulars:
1996 Ram 1500
Extended cab
5.9 engine
206,xxx on the odometer.

Acquired this for $600 at an auction sale locally. Everyone assumed it didn't run, I guess, because nobody was bidding. Luckily, they were wrong, lol. It runs and drives fine...except for this extremely wierd problem. Allow me to describe:

Engine cranks fine. 2-3 rounds and she's fired up and idling. All the way through 3rd gear, it runs relatively smooth for a truck with this many miles. No noticeable miss or stumble. If I go from 0% throttle to 50% or so in one swift motion, it seems to hesitate a little, but I'm thinking that's not at all odd for MFI equipped vehicles.

However, once it shifts into OD, it begins to shimmy, shake, and miss unless I continue to feed the fuel to it. Simply easing into OD is not an option as the power loss is far too great and it begins to lose ground speed unless it's travelling downhill. This occurs at normal OD speed, around 45-50 mph.

If I hold the throttle so that it doesn't shift to OD until 60-65, it still happens, but the increase in rpm seems to make it less of a problem unless I begin to pull a hill in OD. At 65, it loses ground speed extremely fast and as it drops below 60, the shaking becomes unbearable again.

I have replaced the plugs and wires at this point. I noticed an increase in performance through 3rd gear, but not much difference at all once OD kicked in. Then again, the problems that begin at OD are so horrid that I might not notice it even if it was slightly better.

CEL is on and flashing. I get 9 codes...and this is where it has me stumped the hardest at:
First code is: Multiple engine misfire
The next eight codes are....cylinders 1-8 all showing misfires.

I'm stumped. Anybody got any ideas?

 

Have you turned the OD off and drive it (what happens)?.... Is it going into OD or Is the Torque Converter locking up when the shimming starts?

 

It goes back to 3rd gear and smooths out. Runs around 2500 rpm at 60-65 mph.

To describe the gear change to OD...

It goes from 3rd gear (23-2500 rpm @60-65 mph) to what sounds like 4th gear, although there is no marker for a 4th gear on the shift indicator (drops to 1800-2000 rpm @60-65 mph) and only stays for about a second or two before it eases into OD and begins to shake, shimmy, and seemingly misfire (drops to 1500 rpm @60-65 mph).

If I leave the OD on and wait for the shimmy/shake dance to begin, I can push the button and revert it right back to 3rd and smooth it back out. If I leave the OD OFF and drive it from point A to point B, it doesn't seem to have any problems.

***One other thing that I forgot to mention earlier as it doesn't happen all the time is that occasionally the truck will die at idle. Especially if you just lightly tap the gas (like moving forward in a drive-thru). The rpms will increase to match the "tap" and then drop right to zero and die. the idle isn't erratic or anything (like a MAP sensor problem would be), but it has died from a "tap" and even a couple of times while rolling up into the driveway. This isn't an every time problem, and may not even be related to the other problem, but I'm not fluent in Dodge-ese, so I thought I should give it a mention.***

Even if this were a TC problem, that wouldn't explain the 9 trouble codes that indicate misfires on all 8 cylinders.

 

Montec is the guy I would go to with any trans ? It does sound like it's just the OD=4th gear is the problem ...Can you delete or clear the codes...Start fresh to make sure they are not old codes.? Miss fires if not because of a bad Cat could be many things..

 

Could also be a throttle position sensor problem.

 

I'll head back to Autozone tomorrow to let them clear the codes. This is my first Dodge and I don't have a scanner for it.

Wouldn't the TPS throw a code, though? I thought perhaps crankshaft position sensor, but it's not throwing any codes for it, either. The only codes are for misfires, so I'm guessing it has to be on the mechanical side. Trans, torque converter, distributor, cat, etc, but I'm not looking to replace half the drivetrain chasing the problem on a 200K engine, lol.


BTW, I'm thinking that the codes aren't "old" ones because of the CEL. It's just simply "on" when I crank and sit at idle. However, once I begin to drive down the road, the CEL will start flashing. Flashing CEL means misfire detected, correct?

 

The forum search engine will be your best bet on how to trouble shoot all the systems you mentioned... Most if not all can be check with very little if no out of pocket expense...Goodluck

 

just pull the NEG off the bat and pump your brakes a few times...this will clear the computer back to scratch and will clear all code too

 

Thanks for the info on the code clear trick bgibb68. I'll do that first thing in the morning.

I have been searching the forum and it's been a helpful tool for....well, making me think it's one of 100 problems, lol. The symptoms I've described have been discovered to be related to many seemingly unrelated systems in a vehicle. I'm continuing to search, though. I did find several posts that had symptoms almost EXACTLY the same, but the TS in those posts didn't post their final diagnosis if there was one. I will not be one of those guys.

For now, here's a new one to chew on:

Went out to drive it a few minutes ago and see if there might be something else that stood out to add to the list of ever-growing and odd symptoms. Here is what I realized; The lack of idle seems to be worse at night. That's two nights in a row now that it died multiple times when coming to a stop.
Also, pulled the dipstick to check the oil while I scratched my head about all the other symptoms and noticed a faint smell of gas? Looking for an unbiased opinion on what I noticed, I let my 8 year old boy smell the dipstick and he also smelled gas without me telling him what I thought I'd smelled.
So, I began to focus heavily on the oil pressure gauge while driving. I noticed that it spends most of it's time +/- 40, but that it would occasionally bottom out and jump immediately right back up to 40ish. This was during normal 2nd, 3rd gear driving, not at idle.

I'm guessing we're getting closer to the heart of the matter, now.

 

faint smell of gas could be a warped head, blown rings

if it does misfire than just check the wires, plugs, and coils

bad idle could be cloged egr vavle or a broken vac line(or just a vac leak)

here is a link to an oil analysis lab.....just goto the website and get a pack, you just send back a vial of your used oil and they test it and send you back the results dam near the day they get it....it's realtivly cheap to have the test run and it'll say if there is gas and or coolant in the oil.....which should help narrow things down some
http://www.blackstone-labs.com/