Cranks but No Start

joshyboy

New member
Mar 22, 2014
1
0
0
Hi I have a idiot brother, but he has a 07.5 Chevy crew cab and was having startup issues so I replaced the fuel filter primed it and it took off but had a little tick to it then it drove like that for a few days now no start. I changed the filter and housing and I get fuel up to there but still no fire, shot a little sniff of starting fluid and took rite off. He had the H&S XRT PRO race programmer with the dpf delete. So I'm lost
 

Josh2002cc

That Uncle
Apr 2, 2007
1,832
0
0
39
Do you have a scan tool that can monitor rail pressures? If so check command vs actual while cranking.
 

Chad W

New member
Apr 20, 2013
25
0
0
Ft worth, TX
Unplug the pressure regulator on the top of the pump to make it run wide open. I think cranking pressure on LMM was 4500-5000? If nothing else unplugging it with same results will that part out.
 

onebaddmaxxx

Active member
Feb 22, 2009
1,212
1
38
Cecil County Md
Just going by GM si but ive seen the maxs crank on a lower psi


They will crank at any psi, whether it's 0 or max. SI says they won't fire until 10mpa which converts to 1450psi. My truck had an injector dumpin off not letting it build over 6mpa. Little sniff would get it going and ran great. Replaced the injectors and voila, starts like a dream