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Fuel Pressure Test

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Old 07-01-2010 | 10:03 PM
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Default Fuel Pressure Test

2000 Blazer 4.3l

Rented a fuel pressure test, attempting to diagnose my idle stuttering.

Checking the fuel pressure at the schrader valve, the psi jumps to 65 and as soon as the pump is off, it drops to 56 and very slowly pushes back up until 60-62. Is this normal? Been researching all day and seen no mention of it. Other than that, I see little or no bleed from the gauge. If I let it sit an hour or so, it will eventually lose its pressure. Running the engine hovers between 56 and 58 psi. Maybe my gauge is just trippy.

Regards,
KK
 

Last edited by KingKtulu; 07-01-2010 at 10:36 PM.
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Old 07-02-2010 | 12:41 AM
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Have you followed through all the steps in this post?
96+ Fuel System Diagnosis
 
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Old 07-02-2010 | 12:39 PM
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Thanks rriddle,

I have indeed seen and read through the entire post. I have not done all those steps. I stopped short in my confusion of the pressure gauge reading, first jumping to 66 psi when the pump is on but dropping to 54 as soon as its off and slowing building up pressure again until about 60psi. All while the engine is off and ignition key ON. I would expect the pressure to remain constant.

Either that is normal, the pressure gauge is just funky or could that be indicative of another problem (check valve)? From what Ive read the pressure bleed would be much faster and usually drops to 0 instead of building back up slowly.
 
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