Symptoms of bad fuel pump?
Nurrenbern
06-26-2006, 09:18 PM
I have a 99 silverado with a 5.3 when I go to start it it takes alot of cranking to get it started like it isnt getting gas. I recently put a new fuel filter in but still does the same. I was wondering if anyone know the symptoms of a fuel pump going out or any suggestions of what it could be?
waitingforcolumbus
06-27-2006, 12:41 PM
My friends '99 had trouble starting and this forum recommended the fuel pressure regulator. He pulled the vacuum line and gas came out. He replaced the regulator and it's cured.
MT-2500
06-27-2006, 01:00 PM
I have a 99 silverado with a 5.3 when I go to start it it takes alot of cranking to get it started like it isnt getting gas. I recently put a new fuel filter in but still does the same. I was wondering if anyone know the symptoms of a fuel pump going out or any suggestions of what it could be?
Check that fuel pressure. Put a fuel pressure gauge on it . Tape it to mirrow or windshield and drive it and watch it.
Here is some guide lines.
But the 5.3 specs are 55/62 instead of 60/66
Also with a external fuel pressure fuel reg. pull vacume hose off and look for fuel in it.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.
Check that fuel pressure. Put a fuel pressure gauge on it . Tape it to mirrow or windshield and drive it and watch it.
Here is some guide lines.
But the 5.3 specs are 55/62 instead of 60/66
Also with a external fuel pressure fuel reg. pull vacume hose off and look for fuel in it.
Hard to start cold.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.
Nurrenbern
06-27-2006, 09:39 PM
I checked the regulator and gas came out of the vaccum line I will try a new regulator tomorrow thanks for the help.
GAT
06-29-2006, 12:45 PM
My truck took several cranks to start as well. It was indeed the fuel pump.
MT-2500
06-29-2006, 01:26 PM
My truck took several cranks to start as well. It was indeed the fuel pump.
It all goes down to proper testing. And what is a better test than the old fuel pressure gauge?
You have to have the proper fuel pressure. Do not leave home without it.
:grinyes: :rofl: :lol:
MT
It all goes down to proper testing. And what is a better test than the old fuel pressure gauge?
You have to have the proper fuel pressure. Do not leave home without it.
:grinyes: :rofl: :lol:
MT
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