2007 Yukon Denali Intermittent Crank No Start

[rdezs]

When it acts up again, you'll need to watch the live data while you try to start it and see what is lacking. Now that is a PIA.

 

[mattbta]

was the cam sensor you put in OEM? we are guessing not; these trucks need oem cam sensors.

 

[j91z28d1]

are we confusing cam with crank sensor? he replaced cam sensor but these will run without a cam sensor. they won't run without a crank sensor?

I'm a bit lost lol

 

[89Suburban]

Smack the bottom of the fuel tank to see if the pump is hanging up when this happens

 

[Doubeleive]

Smack the bottom of the fuel tank to see if the pump is hanging up when this happens

he said there is fuel pressure when it happens in his initial post

 

[Doubeleive]

HELP! I have a very nice 07 denali that left me stranded with a crank - no start issue. Did it twice now. It will crank and sputter sometimes but no codes snd good fuel pressure. I replaced yhe fuel pump after the first time it did this. Any ideas? All the posts I see are for no crank no start. Mine will crank, just not start. Fuel pressure tests good. It does it when its idling. Idle will drop, truck shuts off, and won't start. I tried holding the pedal to the floor for flood clear but no luck.

when this happens does it do it like "anytime" i.e. after just driving a minute or two or is it only after driving it a longer period of time? or completely random
basically is that part of it consistent or not?

 

[rdezs]

Interesting thing is he mentioned sometimes while idling the RPM will drop and then it will shut off. Would be good to see the fuel pressure when that happens....

 

[Fless]

Interesting thing is he mentioned sometimes while idling the RPM will drop and then it will shut off. Would be good to see the fuel pressure when that happens....

Agreed. Either monitor with a pressure gauge on the fuel rail and a long hose to the windshield, or monitor the PID with a scanner.

 

[Maxpower_454]

Agreed. Either monitor with a pressure gauge on the fuel rail and a long hose to the windshield, or monitor the PID with a scanner.

I tested fuel pressure when it would not start. 52psi. No CEL when it does this. Only happened twice and completely random. Both idling in gear tho. itll seem to start idling rough and then stall and not start. has less than perfect idle normally too. could it be the idle air control valve? Again - No CELs. frustrating....

Yes, oem cam sensor. I only use oem parts. Did a new oem oil oump at the same time and oem front cover gaskets znd oil pan gasket.

I didn't replace the crank sensor as there were no crank sensor issues at the time.

 

[Doubeleive]

I tested fuel pressure when it would not start. 52psi. No CEL when it does this. Only happened twice and completely random. Both idling in gear tho. itll seem to start idling rough and then stall and not start. has less than perfect idle normally too. could it be the idle air control valve? Again - No CELs. frustrating....

Yes, oem cam sensor. I only use oem parts. Did a new oem oil oump at the same time and oem front cover gaskets znd oil pan gasket.

I didn't replace the crank sensor as there were no crank sensor issues at the time.

What if any type of scanner are you using?