Look for dirty connections.

 

I didn't quite follow how you went from the observation of high resistance of a wire to your post about replacing the PCM. If it's just a high resistance wire or connector, can you try bypassing the bad wire with another wire? If one wire melted into another it will be more work but still a lot less costly than replacing everything.

 

the power distribution center is the fuse and relay box located under the hood. It has a built in wire harness that runs to headlamps as well as through the firewall into the underside of the dash. the engine computer (PCM) and its associated harness is totally separate from the power distribution center's associated wire harness. I'll be digging in deeper still, yet worse case scenario is what I was referring to from the factory for like 2 grand. I'll be running to the junkyards and parted out trucks before I go that route. At this point, I'm just keeping this thread current.

note; that information from that post regarding replacing the power distribution center was a quote from the 2001 Dodge Ram service manual.

 

Not that it's any help to you whatsoever, but I endured about two years of random misfiring, O2 sensor codes, and intermittent rough idling. After replacing every single sensor (and the PCM) short of the camshaft position sensor I got new iron Magnum cylinder heads and haven't had any problems since.

I had horrible results with Bosch sensors, the NTK's were a little better, but I found some Delphis that I was happy with. I still have a box full of oxygen sensors to remind me of that experience.

Were it that I had replaced the heads during the first year I would have probably broke even on what I spent in time and money trying to track down the problem through components.

 

Finished tracing all my wires today and found nothing melted, nothing shorted, nothing open circuit...

I'll be taking your advice on the Cylinder Heads and starting to look into that next; now it's time for research.

 

I didn't want to consider replacing the cylinder heads at the time, but after burning out O2 sensors, and collecting IACs and spark plugs for a year or so a mechanic and I surmised that there was possibly an internal crack in the driver's side cooling passage as I kept getting a cylinder 7 misfire code.

Nothing evident when we pulled the heads, but one of the hydraulic lifters was completely shot.

(No problems since, and while I found this forum when trying to diagnose problems I stay for the modification discussions...)

 

Cam shaft lobe lift has occurred.

Lift is off by as much as 0.060 inches and as little as 0.030 inches lower then the camshaft's normal lift of 0.432 inches.

Valves have not been allowing gases to enter or exit properly from cylinders and thus as I would apply throttle pressure, the truck would backfire through the intake from explosive gases not being properly vented into the exhaust stream and instead past the intake valves as they began their open cycle thanks to high pressure exhaust gases being able to overcome the average atmospheric pressure found in the intake at around 14.5 psi.

This, at this point, is my theory until my new cam arrives along with new lifters and I get this engine all together again.

Cylinder heads came off and they looked good. I'll take pictures later on tonight and post. Piston in cylinder number 1 was by far the most carbon fouled, yet considering how poorly the truck had been running and how hard I beat this truck of mine, I must say, the pistons appear to be in great shape in regards to carbon deposits...

 

Do a compression or leakdown test. That will validate your theory, or debunk it.

 

Ccombustion gas leakdown test completed. The result was blue fluid went to yellow upon siphoning almost instantaneously...

Compression test revealed high compression. This was strange to see considering how the combustion gases were found in the coolant system.

After tearing apart the motor and inspecting the heads I couldn't find any cracks or valves that didn't appear to hold a good seal. The truck did overheat on a couple of occasions when my electric fan setup was having issues before I got all the bugs worked out of the system. It seems as though the overheated engine may have developed warped heads and therefore a leaky head gasket which isn't visible to my naked eye inspection.

I dropped the heads off at the machine shop earlier today to be inspected for cracks, pressure tested, and milled 0.006 inches if found to be in good shape. By tomorrow I should have them back and I'll begin their prep along with the rest of the motor in advance of my new cam coming in the mail.

Camshaft is a Sealed Power standard replacement unit with standard hydraulic roller lifters for 316.99 from Summit Racing. Had there not already been about a grand mixed up in this round of repairs to the good old money pit in my backyard I would splurge a bit for a more aggressive cam however I can't afford it at this time. I should have my cam in a week or so, therefore only then will I be able to see if there is any truth to these theories of mine. Time will tell.

 

I really wouldn't bother with the stock heads. The castings are thin to begin with, and shaving them only makes the problem worse. Don't spend money on them, replace them with something better.