JHFIII

Thats the conclusion that I'm reluctantly coming to as well. Im thinking the ECM the more likely culprit just because the vp is a DAP unit with new PSG. Obviously new parts can be bad though. Looks like I'll have to pop the reman ECM off and send it over to Auto Computer Specialist. As luck would have it, its just past warranty. No, I technically have not. When I did the ecm repair it was September last year. I was preparing to move across country, so I just installed it and idled and ran ok just riding around the neighborhood so I turned my attention away from the truck. For the reco

What I dont get is, obviously thats a problem, but is it THE problem since it was misbehaving with the Quad can unplugged? Wouldnt it just default to stock timing?

Well, no joy so far. I unplugged the CAN cable from the quadzilla and its still doing the same thing. Worse tonight actually. Always nice when it acts up right by your house instead of 2 miles down the road. Surging under even very little throttle and at idle tonight. The one thing I did notice is that the thing at idle seems very high. It was 16.5-17deg at idle. I dont know if this makes any difference but when I did my short test drive tonight, I did have the quad on, pl0, with the can unplugged. Hers a vid of it struggling for idle. This is after I plugged the CAN connector back in

Interesting...I havent noticed any funky behavior on the iquad, but that doesn't mean anything. Btw, I have the power and ground set up like you suggested. Actually, after the wt mod, I made a copper bus bar from the pdc b+ to the unused stud, so now I've got two. The ground is run to a blue seas common ground bar on the fender which is referenced to the body and b-.

Will do. I'll report back. I have no idea what firmware version the unit has right now. I bought it about a year and a half ago. Might have to give that a shot as well

Here is a video of how its behaving. This is just driving in my field in circles at 20mph, so in this instance it's at a lower speed than the original post, but it will for certain do this on the road, but rarely driving slowly. Sorry about the angle. https://youtu.be/Zc4xUhwguho

I just have the out of the box tune on it. I havent done any custom tuning at all yet. How can I tell what the stock v2 timing is set at? I couldn't find anywhere in the app with that info.

Hey guys, I've been fighting a heavy bucking and surging issue for some time now. My truck is essentially undriveable, and Id appreciate any insight on where to go from here. Symptoms: Ranging from light to heavy throttle input as long as the engine is under some load, it will develop a violent surge at about 35mph plus. It surges and bucks very badly and on my test drives within a couple miles of my house, its all I can do to nurse it home. It sounds like the footage youve seen of a WWII fighter getting shot down, when it starts to sputter before it catches fire. It idle

Thank you and Dieselfuture for the kinds words. It took a little bit of work. I can assure you there are plenty of rusty, oily and sharp things still there! Awesome pics Tractorman! Down here in Nampa we just have the bracing wind and light snow dustings. Sunsets are pretty sweet though. Alas, my misfire/bucking issue persists. Im going to start another topic on that.

Wow, Thank you guys. Never ceases to amaze me the amount of experience and effort people on this forum put out. I tested my new alternator full warmed up with no acc on and she holds solid at .03. That seems acceptable. Just to add some detail, I was having a bad misfire when I got up to about 45mph. Previously I had changed out a bad vp44 for a DAP unit, and I also had a totally blown up ecu just prior to that, most likely from either a bad ground or the bad alternator I just switched out. In any case, I had been chasing my tail because I had no codes whatsoever and was begi

Understood on the fully warmed up truck. Ive been dealing with some other issues, but it should be ready to test drive now. The alternator should be the last piece of that puzzle. The old alternator was causing some wicked tcc cycling issues and simultaneous apps issues. Ill test it on a warm truck no acc and update.

I did have them test it at the store. It "passed" with .36vac. For reference, there were no accessories on in the vehicle during the test in the video. Only the grids cycling. In the vid, I think it was down to 1 grid cycling at that point bc with 2 cycling it was at 1.65vac vs the 1.0 seen in the vid.

Just to be clear, the spike is only when the grid heater cycles on. Should there be no vac spike when that happens?

Hey guys, After a long saga of chasing my tail, I figured out that my alternator was shot. I had previously measured it with cheapy multimeter and it was holding a .02vac so I sort of put it at the back of my mind and kept on going. Anyway, I realized that my power probe had a true rms setting and remeasured and saw some pretty bad numbers. I picked up a 02 Durango 160 amp hairpin alternator from O'Reilly today. I had them test it before I took it and it tested at .36. They couldn't get another until next Tues so I took it. I installed it, and at idle its pretty much what it