6.0L LQ4 Fuel injection

[bowtie_nut]

Okay fuel injection guys I have a question. I have a 99 silverado with a 6.0L factory engine. It has problems starting. The engine sounds like it is starting so I let off the ignition and it dies. Some times it will start and run fine, then I shut it off and try it again and it won't start. The check engine light never comes on at any time. I have checked the fuel regulator on the fuel rail and cleaned around the throttle body with carb cleaner. Does anyone have any ideas?

[youthpastor]

fuel pressure test? spray some carb cleaner in t-body to see if it starts- if i had to guess- fuel pump- pressure drop will cause hard - no start especially cold- if it is put an A/C Delco pump in it- not aftermarket- my 2 cents- Chris

[bowtie_nut]

when I take the intake ductwork off of the throttle body the engine dies, is this normal?

[youthpastor]

when I take the intake ductwork off of the throttle body the engine dies, is this normal?

cant do that- has to run through maf sensor to stay running- i thought it wouldnt start??

[bowtie_nut]

it will start every once and a while. Once it is running it runs fine. It is just a matter of getting it to start

[youthpastor]

how old is the fuel filter?? sounds like the pump is weak- hard to start cold??

[bowtie_nut]

filter has around 5 years on it and the pump was replaced last summer.

[youthpastor]

yep start with the filter (plugged) - it should be replaced more often- check the fuel pressure- there should be a shrader valve on the fuel lines- i can look tomorrow for specs at work or google it - maybe someone can chime in here- but i think it should be all of 50psi- good luck- Chris

[bowtie_nut]

thanks for the help

[WSSix]

fuel pressure on any LSx engine which includes the iron truck engines should be 58psi at all times. The engine should crank and run with 50 psi but there's a problem if you've only got 50 psi