The 97 wont have a egr valve. Have you had any check engine light on?
Check fuel pressure?
Intake gasket ever been replaced?
That's quite a list of problems you have with your Ram. I'll list a few questions of my own to (maybe) clarify some of the things you have going on in my imagination. Write back when you can...
I'll stop there for now. I have a feeling there's more than one problem at work, especially if your stalling problem happens at lift-throttle (stops, turns, etc). Try to remember the specific codes you've seen in the past and check for new ones if you can.
Sorry about the long list... but there may be more (lol)!
Thanks tosh! No surprise, but this isn't going to be easy.
Yes, more questions...
I'll leave a couple of things for you to check while I'm out (might be gone for a few hours).
Slide under the truck behind the right front wheel area and give the catalytic converter a light whack with a soft mallet or the side of your fist (if the cat's cool). Listen for rattling within the housing. I'm not sure how much of your problem could be caused by an exhaust restriction, but the information is needed any way we slice it.
Check your coil wire for continuity between ends. A bad coil wire can cause some of your complaints, but not necessarily all. A good wire will show continuity when the 20K scale is used on an ohmmeter. It's not that important what the value is, just that it's within that range. The wire may fall apart at either end if it's burned out bad enough to cause driveability problems like yours...
A coil output test might be in order if you get a chance. Pull a plug wire off and insert a screwdriver into the spark plug end. Position the metal shaft near a good ground source and start the engine. You should see a minumum of 1/2" of spark leaping the gap. More is better. If it's less, let me know.
Thanks for slogging along here. I can be a real pain when it comes to information LOL!
Talk later, Ed
Your comment about the guys at the service station telling you the fuel pump comes on when you push the clutch in makes me wonder if you're losing fuel pressure.
There's no direct link between the clutch and your fuel pump, but it sounds like there might be a relationship somewhere there.
Backfiring and running worse as the throttle is pushed harder also fits loss of fuel pressure, as the noise you describe before the engine dies. A hot engine will pre-ignite and rattle as it becomes so lean that it can barely run. The noise you hear might be the engine finishing up its last little bit of fuel pressure.
The heat from a fully-warmed up engine will keep the engine running a little longer after the fuel pump stops. It causes the fuel in the injector rail to boil as pressure is lost. The vapor produced by boiling temporarily props up fuel system pressure and keeps the engine running a little longer, albeit poorly.
I don't see the direct link to the clutch yet. There might not be one. But wiring in the steering column area isn't far from the clutch linkage. Do a little look-see under there to see if something might be loose or coming into contact with either your left foot or the clutch linkage. You might have the engine running while you wiggle as a piece of positive feedback if you find the right spot.
Same thing underhood. Do a little wiggle testing of the harness in the left front wheel area and below the power distribution center. Fuel pump power travels down that section of harness that you can see below the brake booster and goes through a pair of connectors.
This is beginning to sound enough like a fuel pump power supply problem that it might be worth hot-wiring the pump so you can leave the engine off and just listen to the pump as it runs.
Remove the fuel pump relay and jumper between the #30 and #87 terminals (marked on the relay underside). This will run the pump continuously with the key off. In case I'm wrong on the numbering... jumper the two terminals that are turned opposite directions that are directly opposite one another. Three terminals face one way, one turns another. Jumper the odd one to the one straight across from it.
It's all good Bernie. We'll talk later.
Enjoy your weekend!
They're right, Bernie. Your year was the only one with a plastic fuel rail and it didn't come with a test port (dang!). You have to use a special adapter and I doubt they would have one.
Don't try to improvise ... those rails are a little delicate and replacement is expensive. We might be able to work around it for now.
It might mean that you just have a bad fuel pump relay. Or it could be a coincidence. Tough call.
You could try another relay from the PDC in the place of the fuel pump relay. They're all the same, so take one from something that's not real important, like an A/C compressor clutch relay. Check out the terminals in the PDC to see if there might be some signs of heating or plastic damage from heat.
Since you seem to have seen positive results from jumpering the output circuits to the pump, I wonder if there might be a problem with the control side. The PCM grounds the relay to operate it... maybe there's something wrong with the control circuit. The next time you feel the engine losing power, pull the fuel pump relay and listen/ feel for a click as you make and break contact. The fuel pump relay control should be grounded to energize the relay any time the engine is turning.
If all else fails, hotwire the fuel pump relay and see if the engine will run indefinitely like that. I don't recommend you drive it this way, since there would be no way to stop the fuel pump from running in the event of an accident. But if you think it would act up sitting in the driveway, jumper those two terminals.
Just curious... how much gas is in the tank?
Thanks Bernie. The reason I asked was that the inlet filters to the fuel pump module can become blocked on these units if they're the paper type. Fuel levels above 1/2 allow fuel to slosh into the pump module reservoir, bypassing the filter at the base. If you're running out of things to try, put some extra gas in the tank. If it immediately runs better, we might be just looking at a new inlet filter.
Keep up the good work! Talk later,
I have run into a similar condition on several BR trucks and I think the misfiring g and the back firing not setting fault codes. Remove the fuel rail from the engine , put on clean work bench with a cloth under it (white). Remove each injector , one at a time and inspect them for rust or dirt in the ends of the injector.
If you find rust or dirt in the injectors, you will need to replace the fuel rail and all 8 injectors.
Hope this helps. Just reading your history. Thanks, David
Good work, Bernie! The coolant temp sensor isn't something I'd have suspected when the engine starts OK cold, but results don't lie.
I can't find this P0256 code. Probably because it's a diesel code of some sort. I can't explain that one... unless the code reader isn't compatible with your truck. When the scan tool and the vehicle don't connect odd codes like this can pop up sometimes. Don't worry about this one; it probably isn't real.
David brought up a valid point. If you can pretty much verify that you have fuel pressure when the engine is acting up, it just might be a problem with rust collection in the injector pickup screens. It's not iron oxide rust, but some sort of stainless steel reactant. It's uncommon but does happen.
The source is your fuel pump (if it's not magnetic). Fuel passes through a filter/ regulator assembly in the top of the pump assembly that's built of some sort of stainless steel (or similar) material. The stuff we're talking about is shed from the inner walls of the filter/ regulator can and it happens AFTER the filter media, so there's nothing to stop it from heading up to the engine.
Verification goes like David said... remove the rail and tap out the injector screens to see what falls out.
The one thing that bothers me about this is that you have a 4-mile honeymoon each time you start the truck where it runs OK. Restricted filter screens usually STAY restricted and cause the engine to run worse when cold. Tough call, especially with the plastic fuel rail...
Since you've already mastered the art of hotwiring the fuel pump, maybe a fuel volume test would be in order. Get yourself a 5-gallon can, a lenth of 3/8" fuel line and a fire extinguisher LOL. No, really get the extinguisher. Gas is dangerous stuff.
Jumpering on the same side of the truck as where you will be dispensing fuel puts these two components too close together for comfort. Be very careful to avoid stray sparks when liquid fuel is present from fuel line disconnection. Let the fuel evaporate if possbile before firing up the pump.
Then just run the pump and let the fuel fill the gas can. Time the process and watch the fuel flow to see if it markedly peters out after a short while.
Be sure the gas can is clean inside so that any particulates you may accumulate can be blamed on the correct source... your fuel system.
One disclaimer... Some fuel pump modules just naturally pick up fuel poorly at fuel levels below 1/2. You may have to add fuel to get it to 3/4 for this test to be meaningful if it begins sputtering at the discharge hose after 20 seconds.
Last, I thank David (ProAnswerMan) for his interest!
Thanks Bernie. Good luck!