Burbon

Hey guys it is my first time on here which means I am at my breaking point with my 69 C10 project. I have integrated an LS3 Blueprint LS427 with the GMPP harness and operating system which has been dyno tuned(so Blueprint says). The problem started gradually at stop signs as well as under a hard full throttle run and turned into a no run situation. A few runs on the street and one code popped for idle lower than expected, cleared it and it never returned. Then few runs in the garage (because at this point it was starting to die at the stop signs) and some extended periods of inspecting connections, fuel pressure, harness, grounds, engine parameters (with a code reader so no in depth details) and integrating a VSS (did some reading about this setup dyeing under similar conditions without a VSS), etc. I found I could start and keep it running by manually feathering the throttle but would immediately die when I let off the throttle. Then finally a couple of codes popped up, I don’t remember the # of the first code but it had to do with ignition circuit 2 detected a voltage drop as well as a P0606 code. Ok, checked voltages rerouted and changed a few things wiring wise and the ignition relay and switch to eliminate the potential fault. Had Blueprint send a new ECM with the same tune. Installed it. Ran good until it warmed up, shut it down and it will not start back up unless I feather it (so we know it will initially run in an open loop). Ok at this point I call a friend that has some better diagnostic equipment and ASE cert. A few runs in the garage again and found we had a bad MAF sensor but no code for it and the plugs were fowled due to the rich condition that the bad MAF help create, changed out the plugs. Now she started back up ran good until warmed up and went into closed loop and we ran it for about another 20 min then shut it down. We tried to start it back up and again a no run situation and the P0606 code popped back up. We cleared it and she fired right back up but once we shut it down again the code popped back up. I did notice a little pop in the throttle blade at 30% in both opening and closing of the throttle (this was done without the engine running and with his SNAPON diag tool), other than that we think we are just fixing symptoms and not the problem and we believe the problem may be in the tune. Kind of looking for a second opinion here and sorry for the length of the thread.

Project GatTagO

iTrader: (7)

Have you checked fuel pressure?

Burbon

I have checked fuel pressure and flow.

Pop N Wood

iTrader: (1)

Don't forget vacuum leaks

Burbon

Checked for vacuum leaks.

Outlaw 911

My gmpp kit on a 09 ls2 went so lean ( by it self best me and my tuner could figure) it would not start at all. Get a tuner to go in and see if anything is way out of range........

Burbon

I am going to start calling around on Wednesday for a tuner locally. Blueprint is not being helpful at all. If anyone has any suggestions for someone in the central valley area of Cali or a tuner that specializes in "remote tuning" it would be appreciated?

pdsq98gt

My money is either on a tune issue or that throttle body. Is it a stock throttle body or aftermarket? There are also airflow sanity checks the ECM uses for that p0060 code. There are tables that can be modified. Since it’s a 427 you’ll be flowing more air than a stock 6.2 sees. This could be tune issue. But since you said the throttle body catches at 30%, I would lean towards that.