New symptom today after it warmed up. ( it's always after it warms up thoroughly, btw). Today, instead of the PCM trying to time the spark properly ( that's what it sounds like....a really retarded timing)....it started running fine....except it wouldnt rev...and sounded like it was hitting on maybe 3 cyls.
Wow..that's a new one ! I was sitting in the bank parking lot when it happened. I kill it, hop out with my voltmeter, turn the key back on and get 5.1 volts on outer two pins of the tps connector...which I unplugged. Hmm. Now it starts back up and runs normally. I have another new TPS still in the box....going to try that tomorrow, just in case this one is out of spec.
It was HOT outside today ....and I know it's heat related. Bought another new PCM today, ( going to warranty the old one) but havent installed it. Tonight, I drive home at O300 and it's cool outside. Engine is at operating temp for about 12 miles. Stopped for a coke and let it heat soak for 10 min. Started right up and 1 mile later, it "bumps" once. Another mile ( both at about 1400 rpms) another miss. If I had kept driving, it would have eventually gone into "stupid mode"...seeking the correct timing or injector firing sequence ( whatever the heck it's doing) ....etc...but I was home.
Tomorrow ( today)...I'll check the cps. But I'm still not happy with that battery voltage and dont want to install the new PCM until I get that particular issue sorted out in my head. If I have to park this sucker and rewire the entire engine/tranny harness over the next month, I will do just that, in order to defeat it once and for all.
I still cant help but feel like I'm missing something. Battery temp sensor? Valve cover leak messing with the cps ? BTW, fuel pressure is a steady 46 and didnt leak down at all for 3 min...so I think it's fine.
Oldfrog, I'm sure you know more than I do and I sure don't have the wealth of info in my head like ZeeJay does. But I'll give my 2 cents worth on your problems which sound similar to the ones I was having.
After going through 2 PCM's ( on the 3rd), and 4-5 crank sensors (shouldn't even count the 2 aftermarket ones), I took cleaning my engine grounds a step further. I removed the coil bracket and couldn't believe how much oil/corrosion was on the backside and studs. As you know the PCM is grounded to one of these studs which in turn grounds all sensors. I cleaned everything up including removing the studs and cleaned out the holes in the block themselves with a worn battery terminal cleaner brush. Believe this did help some.
I also wondered about my charging system and removed the alternator and the bracket from the block. Again, could not believe how much corrosion/oxidization was on the bracket where it meets the block. And where it wasn't corroded the aluminum was glazed over. As you know aluminum does not like steel and cleaned all this off. While maybe not necessary I ran a new ground wire from one of the bottom/back bolts on the alternator to one of the clean coil studs.
Also since one of the small contacts on middle of the alternator, believe it's the green wire, communicates with the PCM on when to kick the charging field on, I cleaned these contacts off real good too.
On my last bad Mopar crank sensor it would fail mainly due to heat. Once the engine became hot it would start sputtering, coughing and finally die. I've also wondered if oil coating the CKP would cause problems but have been told by several reliable sources the signal will go right through a coating of oil. Still believe I'd test your CKP using the procedure/link in my signature.
Good luck and hope you figure it out!