will crank forever the first time, then starts up most of the time, if its real cold out it might take 3-4 times

new fuel pump @ 58# pressure
new filter
regulator good
plugs good gapped at .060
new battery
cleaned throttle body & iac
did crank shaft variation relearn
on snap-on monitor:
coolant sensor ok 64' within 5' of temp
iac 86 @ idle
maf
map = 96 (running 30)
v=4.59 (running 1.06v)
st fuel trim 0 both B1 & B2
sprayed intake gasket & no leaked found

any ideals??

 

Security light on? Aftermarket alarm/remote start? Do you have spark during this no start on first crank event? Cranking RPM on scan tool?

 

truck is not here at this time.

 

Sprayed intake gaskets as in sprayed with carb cleaner and looked for a change in RPM? Best method in my opinion is to use water. Watch missfire counter on scan tool, use garden hose and run water on intake gasket area and watch for corresponding missfires on those cylinders. You'll have steam/white smoke from the tail pipe. If the gaskets are bad enough, you might stall the engine. Does this condition change when you have a hot engine versus a cold engine?

Does the truck start on a spray of starting fluid? Does the fuel pressure drop when the truck sets? If yes, isolate between leaking injector or leaking down into the return line, leaking to fuel pump check valve, leaking fuel pressure regulator?

 

I like the water ideal

if its real cold out it might take 3-4 times

Does the truck start on a spray of starting fluid? YES
Does the fuel pressure drop when the truck sets? NO
If yes, isolate between leaking injector or leaking down into the return line, leaking to fuel pump check valve, leaking fuel pressure regulator?

 

My money's on intake gaskets being deteriorated and causing a large vacuum leak under a cold start condition. It's best to test for intake gasket vacuum leaks when the engine is cold. I recommend leaving the truck outside over night, bring a bottle of water with you outside and start the truck, watch missfire counters on the first start up and pour water on the intake gaskets.

OEM gaskets have an orange rubber insert inside of a plastic frame. These style gaskets are notorious for cold start issues because the rubber becomes hard and shrinks. When the engine is warm, the cylinder heads expand and seal the gap created from bad gaskets and starts from there on out are usually okay until the engine becomes cold again.

The engine may start first try if you unplug the mass airflow sensor. This puts the PCM into speed density mode and it will ignore all vacuum leaks, and will instead use calculated fuel trim values and compare them to MAP, ECT and oxygen sensor readings. If the intake gaskets are actually bad, the only reason the truck isn't starting is because of unmetered air entering into the intake and skewing the MAF readings. This causes a lean fuel mixture and a hard start/long crank/no start.