Howdy all,
I got the personality keys and primary cartridges loaded, and now everything works like a charm on the scanner. I reset the PCM and correctly set the fuel sync; previously it was at +17 and now it is running generally a lot smoother at 0, per the factory settings. One thing to note is that while the left bank is running dead center, the right bank is consistently running rich, and the scan tool showed 0% trim short or long term. While test driving the truck it has noticeably more power and acceleration, however, I still have the issue of no more acceleration at full throttle, in fourth gear, at around 2200 RPM and 70 MPH. This scanner also has functionality for all the sensors and solenoids in the tranny, and it appears that something is awry with pressure in the governor. I didn't get a good view of the screen while at this exact speed, but on the streets at about 50 MPH I had 74 PSI in the governor while the expected value from the PCM is supposedly 127 PSI. I'm not sure why this wouldn't throw a code but from my little bit of research it sounds like an issue with the governor would cause some of the issues I'm experiencing.

I called the transmission shop I got mine rebuilt at and I'm going to bring it on Monday for them to give it a look.

 

While I'm waiting for the part the transmission shop ordered to come in I've been doing some more digging. I found a couple of old posts from 2009 and 2011 that mention some of the smaller issues I'm still having, namely the rougher idle on a cold start and RPMs varying by 50 or so randomly. A couple of individuals on those posts mentioned the connectors on the harness for the fuel injectors, and that if they break there's a potential for poor connections between the harness and the injectors. I looked under the hood last night and it appears that 6/8 of mine are either completely busted or hanging on by a thread. I'm wondering if this might be a part of my issue as the injectors and their harnesses are the only things other than the brake booster that hasn't been completely replaced and verified. The injectors are from the prior engine that was in the truck when I bought it and had no codes for injectors so I just re-used them. I ordered the new harnesses since, current issue or not, they will most certainly need to be repaired in the future.

I'm gonna verify the fuel/air ratio and LT fuel trim when I get back home with my MT2500 and see if anything looks off. I've been driving the truck around town the last couple of days so I should have some decent data to look at. I shall report back!

 

Update: Got the truck back from the tranny shop, they replaced the governor pressure solenoid, and I also just went ahead and purchased new injectors and harnesses and got everything wired up. Just my luck, there was no change. However this prompted me to dig a bit deeper and just sit at idle and go through all the different live data on the new scanner and noticed something peculiar. It appears that the right bank of fuel injectors aren't going into closed loop, and whenever my engine starts to idle rough and eventually self correct after revving up to ~1100 RPM, is when the left bank switches from open to closed loop. Both of the O2 sensors on the right bank are reading consistently above 1.4 V on idle and I have a constant rich condition (-33% fuel trim at speed) whereas on the left bank I am right on center with fuel trim at +-1% and O2s reading normally.

I do not have any codes whatsoever, pending or stored, and the O2 sensors I replaced are OEM and once installed, corrected the O2 sensor related code I had at the time. Every part and sensor on this truck is a Mopar/OEM part except for the MAP sensor, but that isn't throwing any codes. I also used a smoke machine to confirm if there were any leaks; the only area smoke was coming out of was where the air cleaner seals to the throttle body but that would just mean unclean, metered air going in, and not a leak anywhere past the intake or in the vacuum system. I'm really quite stumped, anyone have any ideas?

 

Beg/borrow/steal/rent some noid lights. Test all the injectors are the right bank. See if one of the lights stays solid. (have to test one at a time..... as I don't think it will run on four cylinders. You are interested in the blink rate of each injector, they should all be the same.)

 

10-4, I'll snag a set of lights at Autozone tomorrow and test the right bank.

As a note I did verify that the harnesses had continuity to the PCM, that the harnesses and injectors were matched up (#2 harness to #2 injector etc), as well as verifying that the new fuel injectors were within tolerance (IIRC most were at 12.3 OHMs and the manual says something about 12 +/- 1.5).

 

From what I saw they all looked rather consistent and none of them were solid.
Back to the drawing board?

 

Yeah, I tend to agree. You changed the injectors at some point right? Did it change anything at all?

 

I changed all of the injectors and associated wiring harness last weekend. The injectors were the same exact OEM Bosch ones and I tested them for resistance before popping them in, they all were 12.3/12.4 OHMs. The wiring on the harnesses was the same gauge wire as the stock ones as well so I’m pretty baffled.

I also just ensured that the correct plugs were plugged into each injector which they were. Oy vey 😵‍💫

 

My gut told me to double check that all of my sensors were in fact purchased OEM and low and behold my MAP sensor was STP. I ordered the Mopar one and slapped it in and voila, my weird stumble issue when I first start up is gone, however, in this constant game of whack a mole, replacing the MAP sensor somehow now generated three codes: P0138, P0141, and P0135, all related to lefthand (bank 1) O2 sensors. I just purchased these O2 sensors back in November, and they are to my knowledge the OEM replacements. All four of my O2 sensors (yay California!) were replaced at this time and I haven't had any issues since, until now. I'm gonna be getting a warranty return on the two sensors and hopefully get a couple of fresh ones installed before the end of the weekend. What a wild ride.

 

Two are for heater failures on bank one. You may want to check that you have power and a ground on both of them.