Like the title says, I've got a 1997 Dodge Ram 1500 4x4 with 199k miles. Has the 5.9L Magnum engine. When I back out my driveway in reverse, and I shift it into drive, it stalls and dies. Sometimes it doesn't want to get started again, but I've noticed that pressing the gas while trying to start seems to help.

This has been an issue for several years, and it seems to be getting worse. The throttle body was taken out last year and cleaned, and the sensors were replaced with new OEM sensors from the dealer. That has not helped the issue.

Outside of that, I know my cylinders 7 and 8 have lower compression than the rest of the cylinders (about 106 psi, as opposed to 125 psi).

The battery is good and has not been removed lately. Truck runs and drives fine in both reverse and drive, it just stalls out when switching from reverse to drive.

I do currently have a CEL, I believe it's emissions related though. Will check later when I get home and report back what the code is.

 

Do you have a scan tool that can read 'live data'? If you do, then post either screen shots or readings of things like, intake air temp, intake air pressure, short and long term fuel trims, coolant temp, rpm, throttle position, etc. Have you had the catalytic convertor/s checked for clogging? Also, remove the fuel cap n see if the problem changes.
A few good places to start.

 

I do have a scan tool that can read live data. Should I get those numbers as it's idling in my driveway?

Catalytic Converter was replaced about 9k miles ago, after the plenum leak was fixed. Truck has a Magnaflow catalytic converter.

 

Yes, idling numbers are a good start. Unfortunately, cats don't last long under rich mixtures or oil burning. However, in your hint about going from reverse to drive might also be an indicator of transmission problems. I'm no RE specialist, but I did rebuild automatics back last century, lol. Mostly mopar 904s, 727s n a few gm trannys. They all work the same. If hydraulic power is still on the reverse band after you switch to the drive gear or vice versa, my first guess might be in the electronic control or a clogged or failing valve body.

 

I don't really think I'm burning oil (or much at all), since the plenum was fixed, and the catalytic converter was replaced at that same time. Since then, my oil levels stay pretty even, except I am losing a little oil from my rear main seal.

I did check my CEL code yesterday, it's P0441 - Evaporative Emission System Incorrect Purge Flow error. I'm assuming it's not related, but I could be wrong.

I took pictures of the live data. It was 3 screens worth of readings. The 3 pictures are below.

 

You're leaning at about 12...not too bad. However, you said your code was for a evap 'incorrect purge flow'. First, try leaving the gas cap off n see if the problem changes. If that doesn't do anything, go after the 'purge solenoid'. Put your hand on the solenoid of just listen for it to tick. It should tick just like a metronome at low RPMs. If your charcoal canister broke up (inside), the pellets will get sucked into the purge solenoid n clog it up. This can effect your fuel trims if the tank is being sucked at constantly via engine vacuum. It can create a near vacuum above the fuel and the fuel pump can't move enough fuel against the vacuum above it. That's the reason I said take off the gas cap n try driving without it. The running too rich tell tale of the fuel trims could be a sign of possible liquid fuel coming up from the charcoal canister n past the purge valve. I've seen that before, albeit, not in a Dodge pickup. Good luck

 

I pulled the vacuum line off the purge solenoid, and 1 line was full of charcoal. Do you think I need a new canister and purge solenoid?

 

Yes. Might be able to clean the solenoid, but, the cannister is shot.

 

If you've got an air compressor or canned air. Blow out the evap lines to the best of your ability. If you wanna replace the charcoal canister, not an altogether bad idea, but you can remove it n dump it out. Usually, this problem destroys the purge solenoid tho. You can try cleaning it n see what happens. But, as far as I can tell anyhow, you seem to be on the right track towards a good n permanent repair.

 

Alright, an update - I replaced the charcoal canister with a new one, and I replaced the purge solenoid as well.. Charcoal poured from the vacuum line at the canister, and at the purge solenoid. I used an air compressor to blow the line out, but had a hard clog in the vacuum line. I eventually got it out using a wire hanger. Got everything put back together, and drove around my neighborhood a bit (and stopping to switch between reverse and drive numerous times) and everything seemed fine. I believe the problem is fixed. Included PCM dataset if anyone was interested.