no start CEL Code 12 and constant flashing (misfire?), tried everything kind of stumped Options

[easternpiro1]

Hi all, een having a problem starting my car ever since I got the transmission replaced.

First, the car was giving me a
CEL 12 wiring and connector g2 + signal, STA signal crank position sensor and ECU
14 and 15 wiring connector, ignition coil, ecu

There is also another 14 code listed in the diagostic -wiring and connector, ignition and ecu
Things I've tried:

I've checked all plugs first to make sure there was no significant damage. (Found some on the main harness connector under the fuse box in the engine bay) checked for continuity, seemed fine.

Checked wire going from ECU to crank sensor for continuity, replaced crank sensor to no avail.
I also changed the cam sensor. Car still won't turn over.

We checked for spark and fuel (I'm getting spark and I'm getting fuel as my FPR is reading pressure and in took out injector plug #1 and used a NOID Light.

We also checked for spark and fuel using an old school method by bypassing injectors and putting fuel directly in. The car DID start but ran horribly and cut off shortly after.

Now I have a constant blinking when I pulled codes.

There was NO signal coming from ecu to injector according to Noid light. So it MUST BE ECU? Nope. Replaced ecu same no start but now I'm only getting code 12 and still getting a misfire code (constant blinking)


Does anyone have any helpful suggestions? A bud of mine and I will be tracing wires today but any assistance would be greatly appreciated.


Placham Thanks for the ECU and help so far. I'm sure we can figure this misery out!

[presure2]

So....since matt brought this back from the dead...(pun intended..lol) i figure might as well add my part of the info, and what i found...

Dustin, Steff, and myself all checked the wiring on this car, over and over, trying to find some fault, and to our surprize, we couldnt find any.
We got to the point where I was ready to pull the harness out and send it to be looked over and rebuilt!!
fortunately, before I did, I decided that I should at least check the crank sensor, even though Matt had told me that he had replaced it already...
Heres what I found.

Where the Crank Sensor mounts to the Oil Pump housing, there are 2 small "guide pins" that hold the crank sensor in the proper orientation relative to the trigger wheel on the oil pump pully.
without them, the sensor can shift and become misaligned with the trigger wheel, or even worse, contact the trigger wheel.

on Matts car, one of the guide pins was missing, causing the sensor to shift and contact the trigger wheel.

heres a pic showing the damage to the trigger wheel, and the missing guide pin.



the sensor out of the car, showing the damage to the sensor



a closeup of the trigger wheel damage



So, I contacted Martin Vernier on facebook, hes a great source for used gen3 or 4 3sgte parts, and he hooked me up with an oil pump pully and sensor for a good deal, and once i got everything reinstalled, i snapped a pic of the clearance between the sensor and the trigger wheel to give matt an idea of how small the clearance actually is...(its around .030 or so, just FYI)



all that time and effort, all caused by one small peice of the puzzle...




your welcome matt!!!!