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5.7 gxi fuel pressure issues

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mww4040

New member
gotta 2002 5.7 gxi, low pressure fuel pump reads zero. high pressure test at rail reads between 85-90. Engine starts fine runs fine on the water . Sputters and wants to die at higher RPMs.
 
the engine needs to be under load and at different RPM (idle, 2000, 3000, and WOT) to check the fuel pressure...

The rail pressure seems high to me (assuming the reading was using the PSI scale)...
 
mww4040 said:
gotta 2002 5.7 gxi, low pressure fuel pump reads zero. high pressure test at rail reads between 85-90. Engine starts fine runs fine on the water . Sputters and wants to die at higher RPMs.
Click to expand...
Being a 2002 I'll assume your GXi is above the B series, so at least C to G, serial number will verify
If correct your fuel pressure should read, Low side 8 +/- 4 psi, High 50-60 psi from idle to WOT

Seeing your at 85-90 psi, your Fuel pressure Regulator took a dump, or the return line back to the filter is clogged solid
 
makomark said:
the engine needs to be under load and at different RPM (idle, 2000, 3000, and WOT) to check the fuel pressure...

The rail pressure seems high to me (assuming the reading was using the PSI scale)...
Click to expand...
makomark said:
the engine needs to be under load and at different RPM (idle, 2000, 3000, and WOT) to check the fuel pressure...

The rail pressure seems high to me (assuming the reading was using the PSI scale)...
Click to expand...
makomark said:
the engine needs to be under load and at different RPM (idle, 2000, 3000, and WOT) to check the fuel pressure...

The rail pressure seems high to me (assuming the reading was using the PSI scale)...
Click to expand...
AllDodge said:
Being a 2002 I'll assume your GXi is above the B series, so at least C to G, serial number will verify
If correct your fuel pressure should read, Low side 8 +/- 4 psi, High 50-60 psi from idle to WOT

Seeing your at 85-90 psi, your Fuel pressure Regulator took a dump, or the return line back to the filter is clogged solid
Click to expand...
 
Yes my guage is PSI , but its a cheap gauge . Not sure if that would be an issue ? Engine model is 5.7 gxi c. I removed the pressure regulator and inspected, found it to very lightly dirty, didn't see any of the paint chips everyone mentioned. Cleaned and reinstalled, not sure how to go about finding and inspecting the return fuel line ? Should I just replace the fuel regulator at the rail ?
 
AllDodge said:
Pressure side, you need to know when the Reg opens
Click to expand...
Ok, finally installed a new oem fuel pressure regulator. Now the pressure at the rail is 49 psi, still reading zero at the low side. Boat fires right up as it did before. my tachometer has not worked for years so i did raise the Rpms up a little still zero reading on low side. would this thing still run and start smoothly if the low side pump is dead ? I unplugged the high side and turned key on and can hear the low pump making some kinda noise.
 
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