fuel pressure question
#1
fuel pressure question
I have been having starting problems with my 2002 blazer.Did fuel pressure test today.Goes anywhere from 48 to 52 psi. Is that enough fuel pressure?
#2
nope,needs 60. time for a ac delco or delphi brand pump. gotta order it online or throught the dealership,locals stores dont have em.
#3
Chris is right, regulated pressure at 48 to 52 is far too low, it must be 60psi to 66psi. Anything below 60psi and you will have problems. Checking pressure and leakdown at the service port will tell you if a problem exists, it will NOT tell you what or where the problem is. Pressure at the service port tells you which ever is lower, regulated pressure or maximum fuel pump output pressure. In other words, if regulated pressure is set to 62psi and the pump can only build 50psi, the reading will be 50psi. If the regulator is set to 50psi, and the pump builds 50psi or more, your reading will be 50psi. With your reading of 48-52, a faulty fuel pump would be a likely guess. But if you want to know for sure what the problem is, you need to check pressure at the fuel filter outlet so all fuel pressure and flow ends at the tester. Must be 73psi to 108psi while the pump is running, and it must remain above 55psi for at least 10 minutes after the pump shuts off. If it fails one or both of those tests, the pump needs replacement. If it passes both, the problem is in the plenum. If the valve plate inside the regulator is stuck open, it will not allow the pump to build pressure. The regulator is waaay less expensive than a pump
Last edited by Captain Hook; 04-05-2013 at 08:27 PM.
#4
Take loose at the fuel filter and hook pressure gauge on output side?
#5
input,that way it bypasses the filter too.
#6
You can check it on either side of the filter, doesn't matter, just need to make sure the filter is not restricted. This coupler connects directly to the outlet of the filter very easily, Buy Dorman - OE Solutions Steel Body Fuel Line Connector 3/8 Inch 800-121 at Advance Auto Parts
then connect the tester to the coupler.
then connect the tester to the coupler.
#7
Replaced the fuel pump today.Starts and runs like a new one.Thanks for the help guy's.
#8
Glad we could help. Thanks for posting back.
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