What is TPS voltage at idle? I do believe there is a minimum spec as well...

 

I'll have to check. I went and talked to a guy at a shop I do some part time stuff for. Only guy I have ever seen be able to do Factory programming outside of a dealer for so many different brands. Guy is like an electrical guru apparently. He's going to take a look Friday. Going to check some senor stuff as well as check the sine waves for the cam and crank signal. He is thinking my cam timing is off.

 

Ok so the TPS issue I believe is the TPS itself. It has 5.15 v supplied to it and if I take it off and move it with a screwdriver I can get 98% throttle. Ordered a Mopar TPS for it.

 

Will be interesting to see how much of a change that makes.

 

Well I had a very interesting day with the truck to say the least. Took it to the electrical guru and the cam and crank signals are good and synced. We noticed the timing advance was all over at idle and the right bank was pulling a lot of fuel. During this the PCM kept loosing connection with the scan tool which was some high end snap on one. Then all of a sudden the fuel trims straightened out and the timing advance settled down without warning. Started idling better too. Took it for a test drive an no more stalling/low idle when coming to a stop and the backfire when taking off was gone. PCM still was loosing connection anywhere from 30secs to 5min intervals though and it was giving as much as 40 degrees advance while braking at low rpm. I was sitting there just fuming like what the @!$% why is it running ok. Well I put some gas in it on the way to the shop. However the fuel that was in it was fresh right after the rebuild plus it ran decent even with the blown headgasket on the little bit of old fuel that was in it before it was tore down, so I am totally confused now. He was strongly suggesting to try a different PCM though. I took it for a drive later and it was still doing ok. I think the plan is going to be put a PCM in it and get the TPS issue resolved. If it still runs ok proceed to proper tuning.

 

The scan tool lowing comms with the PCM is interesting. May or may not be a PCM problem..... but, if the dash doesn't whine about "No Bus"...... it's probably just a bad connection somewhere. Let us know if the PCM solves the issue. (I would also wonder if simply flashing an aftermarket tune to the PCM would change anything.....)

 

Marty sent me a safe for testing tune until the issue gets resolved for good. That's the tune in the truck right now.

 

So it's been awhile since I updated this. Yes the truck is running "fine" but not great. It has no low end torque when it gets above 80 degrees out. Was pulling a 4000lb load a few weeks back and it was almost dangerous. Once moving its fine. Starting to think the cam is retarded. Ordred a degree wheel. Hopefully get that straightened out next week.

 

Alright I have an update. This is going to get technical with cam timing. So since this is a factory regrind they when the cam was ground the centerline changed. The factory centerline is unknown (mopar performance was 112 centerline, so factory likely 117ish). New cam is 110LSA with 4 degrees of advance ground in making it a 106 centerline. To correct this I ended up having to move the cam one tooth advanced, or ~15 degrees to get it close. Now there are no adjustable timing chain sets used anymore so I called crower since this put it on a 103 center line. They said that on that grind it will be fine. However in between checking the cam timing and changing it (getting someone on crowers tech support to handle my question was difficult for a few days). I put the truck back the truck back together without changing the timing to use it and it developed a mysterious misfire and noise that prevented me from using it. Now the timing is changed and the misfire and noise are still there. I tore back into it and checked the chain, rockers, pushrods, and couldn't find anything. Seems to be coming from the tensioner. I did misfire before as well but went away as it ran and the computer learned, I imagine it has to do with the 15 degrees the cam is off. For those of you unfamiliar with the v10 the cam sensor reads off the cam gear (which is why there are not any adjustable sets still being made, nothing else uses that cam gear), there fore the sensor is 15 degrees out of sync with the cam. Here is a clip, let me know what you think.

 

Ok, watched the video, and I hear a metallic clank every now and again, and the tensioner jumps with the noise. It appears that one of your accessories is 'hitching' or sticking, or a bad bearing somewhere, that puts more tension on the belt. It *almost* sounds like the a/c compressor clutch is 'bouncing', just engaging for a second, and immediately dropping out again?