Buffalo444
New member
Alright, so this issue has been going on since I got the truck, but has been getting slightly worse lately and after a little diagnosis I am somewhat stumped.
Truck details:
2006 6.0 Auto
251k miles
stock besides cat/muffler deletes
New HPOP within last 2k miles
New GPs/GPCM at the same time
Ok, so here is what it does... It cranks for 5-7 seconds after sitting over night before firing, then runs a little rough and smokes white until you drive it. I usually let it idle about 3 minutes, because if you don't let it idle it barely has enough power to pull onto the road from curb parking (it actually has stalled a couple times) but when it is running like that, it will barely move but then will suddenly have full power and run normally like flipping a switch. I saw a video about diagnosing it to see if it was a HPO leak or the HPOP, or the ICP sensor, but after cranking it it fired after it saw 500 psi like it should (just seemed to take a while to build pressure) stuck around 30% IPR duty cycle at idle, and only hit 78% duty cycle on a WOT run while hitting 4000psi ICP pressure. ICP desired/seen seemed to stay close enough while running, nothing more than a few PSI away from what it wanted. The only thing that seemed off is that the ICP when sitting was at 0 PSI, which seemed odd because supposedly should show at least atmospheric pressure? I don't know, I'm stumped and I don't want to throw parts at it.
Truck details:
2006 6.0 Auto
251k miles
stock besides cat/muffler deletes
New HPOP within last 2k miles
New GPs/GPCM at the same time
Ok, so here is what it does... It cranks for 5-7 seconds after sitting over night before firing, then runs a little rough and smokes white until you drive it. I usually let it idle about 3 minutes, because if you don't let it idle it barely has enough power to pull onto the road from curb parking (it actually has stalled a couple times) but when it is running like that, it will barely move but then will suddenly have full power and run normally like flipping a switch. I saw a video about diagnosing it to see if it was a HPO leak or the HPOP, or the ICP sensor, but after cranking it it fired after it saw 500 psi like it should (just seemed to take a while to build pressure) stuck around 30% IPR duty cycle at idle, and only hit 78% duty cycle on a WOT run while hitting 4000psi ICP pressure. ICP desired/seen seemed to stay close enough while running, nothing more than a few PSI away from what it wanted. The only thing that seemed off is that the ICP when sitting was at 0 PSI, which seemed odd because supposedly should show at least atmospheric pressure? I don't know, I'm stumped and I don't want to throw parts at it.