Will not start, cranks, fuel pumps not shutting off....

[2quik6]

I think I have the problem solved! I have replaced the crank sensor, and so far so good, has started flawlessly for about 30 times now... Would not start twice yesterday before I replaced it.
Suspect it was reporting rpms when the motor was not running...hence not starting. I also contacted Paxton to determine what signals the Paxton FMU needed to command the external fuel pumps on..it needs a boost signal which is 0 psi, atmosphere, and rpms...so it had 0 psi since motor was not running, and rpms most likely from faulty crank sensor.
Will post back if anything changes...but solved for now.

[2quik6]

NOPE..spoke too soon, did it again today after starting fine 30+ times....took me about 10 minutes and 20+ tries today to get it to start....so on to changing the cam sensor hopefully this weekend....

[2quik6]

Changed cam sensor, still has same issue...has also started dying driving down the road...has done that twice now. Currently removing the intake and inspecting all the wires and swapping out the coils and spark plug wires while its off....then on to removing the paxton FMU next.

[rbabody]

Do you have access to a scan tool?

[2quik6]

Originally Posted by rbabody

Do you have access to a scan tool?

Not at the moment, a friend of mine has the Snap On but he is 2 hrs away. Will get it the next time we see each other, which may be in Bowling Green next week.

[2quik6]

I found the problem...after redoing all of the wiring connections for the Paxton SC FMU as they were all crimped, I took them apart and soldered them all...still had the problem... So I removed the Paxton FMU altogether and re-soldered the original wiring for the cam and crank sensors back together to the factory ECM..problem resolved. Have driven over 1000 miles over the past 2 months without a single issue.
Just had to be careful not to get into boost, now I will be buying a new fuel pump, bigger injectors, and reprogramming the factory PCM, and remove the 2 extra external pumps from the Paxton kit.

[VENOMOUS1 RACING]

Originally Posted by 2quik6

I found the problem...after redoing all of the wiring connections for the Paxton SC FMU as they were all crimped, I took them apart and soldered them all...still had the problem... So I removed the Paxton FMU altogether and re-soldered the original wiring for the cam and crank sensors back together to the factory ECM..problem resolved. Have driven over 1000 miles over the past 2 months without a single issue.
Just had to be careful not to get into boost, now I will be buying a new fuel pump, bigger injectors, and reprogramming the factory PCM, and remove the 2 extra external pumps from the Paxton kit.

Paxton fmu is a POS for sure! Glad you figured it out