Troubleshooting Help
Thread Starter
Staging Lane
Joined: May 2007
Posts: 53
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Troubleshooting Help I purchased a 2001 Silverado Z71 with 5.3 (126K miles) last year from a buddy of mine. Truck had been parked since 2014 prior to him getting it. When he got it the fuel pump was bad so they replaced the fuel pump and it ran normal but when they tried to drive it one of the brake lines busted so they parked it again. This past weekend I went to do some work on it, drained whatever bad fuel was left in the tank, replaced the fuel filter and put in 5 gallons of fresh fuel. I tried starting it and quickly noticed the exhaust was crazy loud. Well turns out someone stole the damn catalytic converters from the truck, they cut them clean off. But also noticed that the truck was having a hard time getting started. I was finally able to get it started but it wouldn’t run on it’s own power, I had to continue pressing the gas pedal just to keep it on. I noticed that it wouldn’t really rev up even if I fully pressed the gas pedal all the way down. It would only rev up a little as if it was starving for fuel and would turn off. RPM's would only go up a little. I replaced the plugs, wires and air filter and no help.
Is it possible that the fuel pump they replaced has gone bad? I plan on checking the fuel pressure this week with a fuel pressure gauge and see what it shows, this will have to be done with just the key on since it won’t run on its own. From what I have gathered, static should be between 55-65 psi and with the vehicle running should be 50-60 psi. Is this correct? Any other things I can check to help troubleshoot this issue?
Is it possible that the fuel pump they replaced has gone bad? I plan on checking the fuel pressure this week with a fuel pressure gauge and see what it shows, this will have to be done with just the key on since it won’t run on its own. From what I have gathered, static should be between 55-65 psi and with the vehicle running should be 50-60 psi. Is this correct? Any other things I can check to help troubleshoot this issue?
TECH Fanatic
Joined: Jan 2009
Posts: 1,063
Likes: 475
From: Bostwick, GA.
A set of NEW stockers from the bag are cheap enough. Lots to choose from.
Make SURE they are gennie parts, and not some knockoffs.
Look at the injs. There should be part numbers on them.
FWIW, most of the junk yard guys that send me injs are having the exact same issue.
Make SURE they are gennie parts, and not some knockoffs.
Look at the injs. There should be part numbers on them.
FWIW, most of the junk yard guys that send me injs are having the exact same issue.
Thread Starter
Staging Lane
Joined: May 2007
Posts: 53
Likes: 0
My buddy has a set of injectors he removed for his low mileage running 4.8 when he went to some larger ones. Would they work on my 5.3? His truck is a 2002 and mine is a 2001 if that makes a difference.
The fuel pressure gauge arrived today so decided to give it a try. Did a static test with just the key on and the needle pegged out at 100. Gauge reads from 0-100 psi. Tried it a few different times with the same result. I removed the air inlet tube from the throttle body to take a look and got the truck running. Seems like it was idling low though. I cracked open the throttle a little and the truck died. Tried it again with the same results. I reconnected the air intake tube ack onto the TB and looked over everything to see if I could see anything out of place but no luck. I tried turning it on again and after some times I was able to, I let it run for about 1-2 mins and cracked the throttle a little and it died quickly. What would cause high fuel pressure? I have a video of it running but have no idea how to post it.
The fuel pressure gauge arrived today so decided to give it a try. Did a static test with just the key on and the needle pegged out at 100. Gauge reads from 0-100 psi. Tried it a few different times with the same result. I removed the air inlet tube from the throttle body to take a look and got the truck running. Seems like it was idling low though. I cracked open the throttle a little and the truck died. Tried it again with the same results. I reconnected the air intake tube ack onto the TB and looked over everything to see if I could see anything out of place but no luck. I tried turning it on again and after some times I was able to, I let it run for about 1-2 mins and cracked the throttle a little and it died quickly. What would cause high fuel pressure? I have a video of it running but have no idea how to post it.
