My trucks getting hard to start!
09-06-2009, 06:21 PM
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My trucks getting hard to start!
Its a 4.8 in a scsb and it has 130 on the clock i replaced the filter and fuel filter. When i try and start it, it has to crank a while before it will start up then it doesn't hardly want to run. It has died once or twice while changing out of reverse when backing out of my driveway.
09-06-2009, 07:43 PM
#5
Checking the fuel pressure regulator is easy, just pull the vacuum hose off of it and check for the presence of fuel, if gas drips out or there is a strong gas odor, the fp reg is leaking and needs to be replaced. The fuel pressure regulator is located in the center of the driver's side fuel rail...it's a common failure that will cause a hard start. To check the fuel pump, you need a manual fuel pressure gauge hooked in to the test port, then observe fuel pressure while cranking and running. I believe that it should be around 60 psi at idle, but I'm not 100% sure...that spec is floating around here somewhere if you do a search. As for the throttle body, you just visually inspect it...if it's full of carbon, it needs to be cleaned. If the IAC and it's passages get gummed up, it will cause all sorts of starting and idling problems. I clean my throttle body every 12 months or 12k, whichever comes first. If all of those check out OK, I'd start checking that you have a good strong spark during cranking...but start with the things mentioned and take it from there...
(of course I'm assuming that battery voltage is good and it's cranking strong...)
(of course I'm assuming that battery voltage is good and it's cranking strong...)
09-06-2009, 08:04 PM
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Checking the fuel pressure regulator is easy, just pull the vacuum hose off of it and check for the presence of fuel, if gas drips out or there is a strong gas odor, the fp reg is leaking and needs to be replaced. The fuel pressure regulator is located in the center of the driver's side fuel rail...it's a common failure that will cause a hard start. To check the fuel pump, you need a manual fuel pressure gauge hooked in to the test port, then observe fuel pressure while cranking and running. I believe that it should be around 60 psi at idle, but I'm not 100% sure...that spec is floating around here somewhere if you do a search. As for the throttle body, you just visually inspect it...if it's full of carbon, it needs to be cleaned. If the IAC and it's passages get gummed up, it will cause all sorts of starting and idling problems. I clean my throttle body every 12 months or 12k, whichever comes first. If all of those check out OK, I'd start checking that you have a good strong spark during cranking...but start with the things mentioned and take it from there...
(of course I'm assuming that battery voltage is good and it's cranking strong...)
(of course I'm assuming that battery voltage is good and it's cranking strong...)
