I am wondering if anyone knows what rpm the crank sensor has to see before the ECU calls for fuel? I'm hoping its not cranking RPMs but actually running RPMs

 

I wanna say injectors pulse off of the cam sensor

 

Could be wrong but i thought the engine will run with a bad cam sensor?

 

Well, I am just having a hard time finding at what exact point the computer decides to call for fuel after the initial 2 second prime.

I can't seem to find the answer anywhere.

 

I am going to try this tinker toy. I can set the minimum voltage to 9v and the high to 12.6 for a starter safety switch. I was trying to do it with the fuel circuit but I think this might be a better option.

 

I ls swapped a 74 caprice not to long ago. It had a vvt/dod 5.3. We removed everything and swapped a performance cam, 4x gear etc in its place. Well not knowing any better we reused the original vvt cam cover.

Well with a vvt/dod delete u cant use that cover. It positiones the cam sensor farther from the cam gear. We couldnt get an injector pulse. Even Verified cam pulse with hptuners. Zero.

Ended up Pulling the vvt cover and replaced with a ls2 cover and car fired right up. No issues since.

 

As soon as the crank starts to turn . You can test this. Just remove the crank sensor
from the engine, turn on the ign , flick a wrench across the face of the sensor, and the pump will come on. Steve

 

yeah, there's no specific rpm, as long as the engine is seen to be turning the fuel pump stays on.

What exactly are you trying to do?

 

I have a 47 Chevy Pickup that has an old floor start switch. The factory style ignition does not have a crank position built in. I am trying to keep the factory feel of the truck, but I don't want to be able to accidentally hit the start switch while its running.