Yes I have rpm on scan tool while cranking. I can clear the code when I do get it to run and when it starts acting up and shuts off that's the code it throws before it dies. So you're telling me that doesn't mean squat? Honest question
if you have rpm on the scan tool (
allll the time, every time while cranking; starting or not starting), then there's nothing wrong with the CPS, or the wiring to PCM from the CPS, in my opinion.
if you have a 'scope..what are you seeing 'fall out' when the truck dies?
FDCS, CID, CPS signal(s)?
I'm more interested in what you mean when you said "when it starts acting up and shuts off"...
like it 'acts up' in what manner before it dies?
CEL/SES comes on prior to shutting off?
or runs rough (how so) before it dies?
what is the actual code being stored in the PCM? is a CEL/SES light being illuminated prior to the engine turning off??
it
sounds like the cam signal may be dropping out...possibly from cam/gear walk...but maybe not if you abso-***king-lutely have rpm on scan tool under all cranking conditions.
have you checked your vRef voltage(s) on all 3-wire sensors?
one bad sensor can draw down the vRef enough to cause the (only important one) CPS signal to drop out.