Furunner

All of the grounds you mentioned were checked and double checked weeks ago. I will take a close look at the ECU. Other than the ECU, is there anything else that could affect both fuel delivery and transmission shifting? Faulty O2 sensor somehow? This is getting bizarre to me

Gevo

An electrical problem can connect all of this. A bad ground definitely.

I agree with post above that a bad CSI will not cause any of your issues described.

Glad it's running again.. but I suspect you gonna end up in square one soon.

RJR

I would carefully check out the VAFM and the TPS. Both of those inform the ECU about input conditions for the engine (air flow and throttle position). It uses that information to set fuel flow and transmission shift points, among other things.

A bad VAFM can cause the ECU to cut off fuel flow, preventing starting. This can happen even if the circuit-opening relay is working and the fuel pump is running.

Check out this recent thread. A lot of similar issues here...
https://www.yotatech.com/forums/f116...s-mean-281830/

Furunner

Thanks! I read that entire thread and I'll double heck the VAFM tomorrow. I took the manifold off today to get to the injectors and I'm glad I did as I made a few discoveries. There is a ground behind the manifold against the firewall and the bolt securing it was OFF so I reconnected it. Not sure what it is grounding but the injector wires are all in the same bundle that it leads to. I pulled all of the injectors and test fired them and also ran some Sea-Foam through them and they all fire and have a nice stream. I'm not sure if they are supposed to have more of a "spray" vs a "stream" but I wasn't putting high pressure through, just enough to test it and get sea foam through with a homemade syringe and tubing. I will DEFINITELY check the VAFM again once I get it back together if problems persist because much like the thread that you posted, I have spark, compression, fuel pressure at the rail, a new TPS installed correctly, and much more! If anyone knows more about the ground that was disconnected behind the manifold on the EGR side please tell me what that is supposed to be grounding! Thanks again everyone, I feel like I'm getting closer.

Gevo

I'm impressed that you were able to test your injectors in such a way.

THe grounds on this car as EXTREMELY important, everywhere you read on this site people say so.. for good reason. I found out through months (literally) of testing, adding test grounds, thinking, reading, thinking, testing etc... Test your E1 wire(s) against a known and confirmed good ground (my suggestion is the bat neg terminal). The E1 ground runs to multiple components with a BROWN wire. It goes to your VAFM, and no ground there would cause issues. I don't know exactly which ground wire you are referring to, I don't have one on the EGR side going to the firewall. Picture?

Check your wiring diagram here -> http://snjschmidt.com/wiring/ (click on the three engine control diagrams) and use it to check the grounds to the components. Make sure that not only you have continuity but also resistance of no more than 1 ohm.

I may seem a bit enthusiastic about the grounding situation... I'm coming from spending 2 hours re-doing all my grounding wires today

Furunner

UPDATE

I put everything back together Monday night and so far the truck starts, idles, drives, and shifts perfectly. Two days prior I barely made it to my friends garage and had to drive in second gear just to keep the RPM's high enough to keep it from dying. Sorry no pictures but there is a ground wire behind the manifold that is very difficult to see and reach without taking the manifold off. This wire was loose and the bolt that secures it was sitting right below it. With the manifold off I was able to trace the wires and one of them was the ground to the TPS. This I believe was the root cause of my issues. Thanks to everyone who posted suggestions, especially those of you like Vasinvictor and Gevo who emphasized the importance of the ground wiring. I took a hard look at all of the wiring because of the comments so thanks again. Along the way I replaced the EGR with a newer looking one from the junkyard and repaired the wire to the EGR temp sensor which someone had cut at one point. It's been a few days and about one hundred miles and the code 71 EGR check light hasn't come back either. It's funny what you find digging around an older vehicle, I'm still scratching my head at some of the stuff somebody once did to this truck. Hopefully this is finally the end to this Saga.

jbtvt

Late to the party, but thanks for posting the detailed wrap up. I hate cliffhangers