Spittin, Sputterin, Smokin

[1MoCast]

First of all I want to say this is a great forum! I have got some great information by researching past threads. Unfortunately, not quite enough to fix this problem...
My daughter was driving the 1999 Ram 1500 (5.2L) a week and a half ago on a sub-zero day and called stranded on an on ramp. She said it was running not quite right, then puked out as she slowed. I went down and limped it home. It ran out "OK" at road speed, but stalled at idle. The code I got was a P0300: General Misfire (duh!). Cleared that and checked everything obvious over. I ran it again and after a time got P0172: Bank 1 too rich (or something like that) I changed the plugs as I was unsure when they had been changed (I bought the truck a year ago). They looked OK except #4 had some carbon and #8 looked terrible, almost half burned off. I thought that had to be it, but no. The next try a P0204: Injector 4 open. I checked the injector and got 12.xx ohms... same as the others. Cleared those and got a P0203 and Injector 3 ohmed OK. The rough idle research I did prompted me to change the IAC which didn't help.
The smoke made me look at the oxygen sensor. I had replaced the downstream this fall so I questioned the upstream. The weird thing was that I could unplug it and run without setting a code? I read this era trucks may not catch the O2 sensor faults reliably, but still no joy.
During my reads it was mentioned that #8 plug fouling was a symptom of a plugged catalytic converter. I rigged a gauge up to the threads on the old O2 sensor and noticed the exhaust pressure would spike when the cat rattled. And again I found "the answer" and drilled some holes and hollowed it out. And again I was wrong.
On my combination test drive and hole plug run after reaming out the cat, I set a P0203, cleared it and set it again on the way home. I swapped the #3 injector with the #1 injector and went to get some gas (I have gone though a half tank just troubleshooting) I set P0203 again on the way to the station and again on the way home.
I downloaded the pin out and the wire has continuity from the ECM to the injector. I also put a 194 bulb in the injector plug and get a light when turning over.
So now what? I am out of ideas.
Sorry for the long post.
Thanks

 

[rowdyram]

This is going to sound weird but... Its your tps causing the injector coded. There is software anomalies with the jtec controller, the tps shorts the 5 volt sensor feed and the result is false injector codes, sometimes all 8! And a rough run or stalling. If your injector resistance is even within 1 ohm and 10-16 replace the tps, only other likley possibility would be the pcm.

P0171 is bank 1 lean.
You may or may not have multiple issues. I suggest tps clear codes and see what happens

 

[1MoCast]

I went to the parts store right away this morning and purchased a TPS. Before leaving I verified the signal was in range on the old one. It was .7 volts at closed throttle and 3.9 @ WOT. New one installed gave me the same voltage and same crappy running... must be the PCM then?

 

[Merc225hp]

I would be checking the cam sensor in the dizzy, worth a try.

 

[rowdyram]

In some rare cases it is the wiring for the tps, or yes the PCM. I've dealt with this a lot on magnums and 4.7 v8s and has always but once been the tps the other time was the wiring... Not saying those are the only possibilities but by far the most common.. The code indicates on open in the injector circuit so the possibilities are,
Injector
Injector wiring
Injector driver
PCM low side monitor
Or something causing the low side monitor to misinterpret the voltage value.

 

[1MoCast]

Well it was worth a try...thanks for the advice I was hoping it was the fix.
I feel I eliminated the injector as a possibility by swapping to another hole and the code didn't follow plus it ohmed out good. The wire had continuity from the PCM to the injector plus I stuck a light bulb in the plug and the light bulb flashed when turning over. I found a PCM at a local Auto Parts Recycling Yard for $75, I will go get it tomorrow and hope that's it. I really need to get the truck back on the road!

 

[BlackMagnum2000]

+1 on the cam sensor. It has caused me very weird issues. It's just under the distributor cap. Pretty easy to reply so long as you can reach back there.
Also at any time has this truck had the distributor out of the engine?

Edit: just saw you're going to get a PCM. That may also be the cause of it. This seems like a pretty weird problem to me. Hopefully it will solve it. If not, I can't quite think of anything else that hasn't been mentioned. But I'm sure Merc and rowdyram have you covered.

 

[rowdyram]

The PCM will likely not work. The CCD bus will not communicate with a module that has a different vin. Only 2 ways to change it. Cardaq m or DRB3.
But I believe the testing you have done is sufficient to verify the integrity of the injectors the circuit and the injector driver. Do you have a scan tool.
I also agree the can sensor could cause some of your symptoms
But I don't see any way it could cause the injector codes and I would start with diagnosing the codes first and see where it leads you.

Edit
This just hit me... Your oxygen sensor heaters are on the same circuit as the injectors from the ASD relay(you'll have to double check this but this is the common Chrysler design). You could try running with your o2s unplugged. If its better plug in 1 at a time while running and check for problem to return.

 

[BlackMagnum2000]

The PCM will likely not work. The CCD bus will not communicate with a module that has a different vin. Only 2 ways to change it. Cardaq m or DRB3.
But I believe the testing you have done is sufficient to verify the integrity of the injectors the circuit and the injector driver. Do you have a scan tool.
I also agree the can sensor could cause some of your symptoms
But I don't see any way it could cause the injector codes and I would start with diagnosing the codes first and see where it leads you.

Edit
This just hit me... Your oxygen sensor heaters are on the same circuit as the injectors from the ASD relay(you'll have to double check this but this is the common Chrysler design). You could try running with your o2s unplugged. If its better plug in 1 at a time while running and check for problem to return.

I've had my computer on a buddies 01. I think it would work. But Idk you probably know better than I do.

+1 on scan tool. They can help a lot if you can get your hands on one.

 

[dodge dude94]

As long as the PCM is from the same year, it'll run the engine, just flip a ***** with the cluster/VIN.

 

[rowdyram]

I've found it to be hit and miss on the Vin. Fixed a few no starts by changing the Vin. How does a PCM loose its Vin? I'm not even sure Chrysler knows but its common. On the other hand I put a used IPC in a jeep grand last week, no problems

 

[BlackMagnum2000]

Idk. We all know these trucks are extremely moody. Or maybe that's just mine. Idk...

 

[dodge dude94]

No, most of them are that way.
Like I've said in the past, You're working on a Dodge, anything is possible.
If you think it *SHOULDN'T* happen, it probably already has, which is why you can figure out what's happened.

 

[BlackMagnum2000]

No, most of them are that way.
Like I've said in the past, You're working on a Dodge, anything is possible.
If you think it *SHOULDN'T* happen, it probably already has, which is why you can figure out what's happened.

Like with my cam sensor. Replaced it so I ruled it out. A month later.. it turned out to be the problem.

Okay time to stop thread jacking. We always end up doing this. back to the coffee house

 

[dodge dude94]

Like with my cam sensor. Replaced it so I ruled it out. A month later.. it turned out to be the problem.

Okay time to stop thread jacking. We always end up doing this. back to the coffee house

It's not EXACTLY threadjacking....it IS bouncing ideas around a lil.

 

[Merc225hp]

I asked Mr. Alec to have a look at this thread, he knows these pcm's like the back of his hand. Me for what the cam sensor costs that would be my next part to replace.

 

[aofarrell2]

Check your camshaft sensor. It can do some funny things.

I wouldn't be so fast to assume your PCM is bad. Most of the times someone thinks a PCM is bad it isn't. They are tough.

Have you tried the wiggle test? I don't always recommend it but in this case I would highly recommend it. You will grab your wiring harness and wiggle it some. It doesn't need to be much but enough to move the wires around inside it some. Do it in several different places.

If your engine runs differently when wiggling the harness, you have a faulty harness.

I've had the exact same problem, turned out to be a bad harness.

Also check the ground wires underneath the battery and on the radiator support. If any of those are missing, corroded, or otherwise damaged, they can cause the PCM a lot of grief. There should also be at least one ground strap going from the cylinder head to the firewall. I should also remind, do NOT lubricate the grounds!!! Simply clean them, do NOT grease them or lubricate them or use any terminal protection other than silicon dielectric.

As well you should also test the resistance of the injectors. They should read around 12-14 ohms, give or take depending on the outside temperature. Any injectors with a significantly different reading than the rest are bad. While you're at it, check the pins on the injector connectors on the harness. Sometimes the pins can get loose or corroded and cause problems, even if you get continuity through the wire.

The 1998.5 up PCMs should be VIN programmed even if the truck runs with it. When a dealership programs the VIN it's not simply setting the VIN through a scantool, they also ensure that you have the correct flash for your truck. Just because your PCM has the right part number does NOT mean it has the correct flash (things like gear ratio so your speedometer reads properly, etc.). Also other components on the CCD bus may not like a PCM with a different VIN.

As far as the truck running with a PCM that has not been VIN flashed, it'***** and miss because there are enough different flashes, and also it depends on the setup of the truck (CTM and body controller, etc.). You can get away with it sometimes but I strongly recommend having it VIN flashed regardless.

 

[BlackMagnum2000]

Also if you buy a cam sensor be careful as to what brand you get. The one I got was complete ****. Didn't work at all. If in doubt, buy one from a dealer that's what I ended up doing.

 

[dodge dude94]

#TechJockeyInTheHouse

 

[rowdyram]

So I looked on identifix to see what common repairs are for your code, here they are in order of likely hood.
1 TPS
2 PCM
3 Exhaust valve or spring.

Before replacing PCM perform compression test