1997 GMC Sonoma Fuel Pump Intermittant?

Tiny
RETICULOUS
  • MEMBER
  • 1997 GMC SONOMA
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 214,791 MILES
Hi, I have 97 Sonoma that I put a brand new fuel pump in about a year ago. Just today it seems to have started having problems again. When the vehicle is cold it fires right up. I can hear the pump engaging and everything runs tip top. After driving around for 20 minutes or so, I will have some acceleration issues like it's not getting fuel, and then after a couple of minutes of that it will die and not start again. At that point I can only hear the pump every few tries and it turns back off shortly afterward. When I let it sit for an hour or so, it will fire right back up and I hear the pump like nothing happened. This has happened twice. I am wondering if I need to replace the pump again or if there is something else causing this issue?
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Saturday, March 28th, 2009 AT 6:55 PM

7 Replies

Tiny
MERLIN2021
  • EXPERT
Check the connector back there, they sometimes melt, or corrode, pull it apart and inspect it.
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Saturday, March 28th, 2009 AT 7:05 PM
Tiny
BILLYMAC
  • EXPERT
Hi well unfortuneately it is hard to grt quality parts anywhere. But yes your pump will have to be replaced again. You can buy a oem pump and it will last longer. But much more expensive. Good luck billymac
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Saturday, March 28th, 2009 AT 7:06 PM
Tiny
MERLIN2021
  • EXPERT
I'd say do what I said, if ok, test pressure BEFORE replacing. Also check the relay, contact may not be closing all the time.
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Saturday, March 28th, 2009 AT 7:18 PM
Tiny
BILLYMAC
  • EXPERT
SORRY MERLIN DID NOT SEE YOUR POST BILLYMAC
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Saturday, March 28th, 2009 AT 7:25 PM
Tiny
RETICULOUS
  • MEMBER
What should my pressure be, and what power should my relay be running?
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Saturday, March 28th, 2009 AT 7:56 PM
Tiny
ROBBIET
  • MEMBER
I had a similar issue with my civic once. I changed the main relay and that was the cure. Not sure whether our sonomas have a main relay or just the fuel pump relay, but save yourself the dealer expense and Try changing the relay that controls the fuel pump with one from a junk yard first.
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Friday, April 3rd, 2009 AT 12:46 AM
Tiny
MERLIN2021
  • EXPERT
FUEL SYSTEM PRESSURE TEST 1. Perform On-Board Diagnostic (OBD) System Check. See ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK. After performing OBD system check, go to next step. 2. Relieve fuel pressure. See FUEL SYSTEM PRESSURE RELIEF. Connect Fuel Pressure Gauge (J-34730-1A) to fuel pressure test port. Turn ignition on with engine off. Fuel pressure should be 60-66 psi (4.2-4.6 kg/cm 2 ) on CSI fuel system and 56-62 psi (4.0-4.4 kg/cm 2 ) on SFI fuel system, and should hold steady. If fuel pressure is as specified, go to next step. If fuel pressure is not as specified, go to step 9). 3. Turn ignition off for 10 seconds, then turn ignition on. Fuel pump should run for 2 seconds. Observe fuel pressure. If pressure is within specification and holds, go to step 5). If pressure is not within specification, or is within specification but does not hold, go to next step. 4. Turn ignition off for 10 seconds. Turn ignition on. Pinch off fuel pressure feed line. If pressure is as specified and holds, go to step 6). If pressure is not as specified, or is as specified but does not hold, go to step 8). 5. Warm engine to normal operating temperature. From idle, open throttle quickly. Observe fuel pressure. If fuel pressure is within specification, see the TESTS W/O CODES article. If fuel pressure is not within specification, go to step 8). 6. Check for partially disconnected fuel pulse dampener/pulsator. If dampener/pulsator is partially disconnected, go to next step. If dampener/pulsator is okay, go to step 13). 7. Repair connection at fuel pulse dampener/pulsator. After repairs, go to step 28). 8. Check fuel feed line between pinch and CSI/SFI unit. If fuel feed line is restricted or leaking, go to step 27). 9. Turn ignition off for 10 seconds. Turn ignition on. Fuel pump should operate for about 2 seconds. Observe fuel pressure after fuel pump stops. If pressure is present, go to step 14). If pressure is not present or drops, go to next step. 10. Turn ignition off. Connect a fused jumper wire between battery voltage and fuel pump test terminal. If fuel pump operates, go to next step. If fuel pump does not operate, go to FUEL SYSTEM under NO-START DIAGNOSIS. 11. Check for plugged fuel filter, plugged fuel pump strainer, restricted fuel line or disconnected fuel pulse dampener/pulsator. If a problem is found, go to next step. If a problem is not found, go to step 13). 12. Repair or replace plugged fuel filter, plugged fuel pump strainer, restricted fuel line or disconnected fuel pulse dampener/pulsator. After repairs, go to step 28). 13. Replace fuel pump. After repairs, go to step 28). 14. Turn ignition off for 10 seconds, then turn ignition on. Fuel pump should operate for about 2 seconds. Observe fuel pressure. If fuel pressure is greater than 66 psi (4.6 kg/cm 2 ) on CSI fuel system or 62 psi (4.4 kg/cm 2 ) on SFI fuel system, go to next step. If fuel pressure is not greater than specified, go to step 16). 15. Relieve fuel pressure. Disconnect fuel return line. Attach a fuel hose to fuel regulator return line and place in a container. Turn ignition on. Observe fuel pressure within 2 seconds after turning on WARNING: Begin fuel system trouble shooting and diagnosis with fuel system pressure test. Relieve fuel system pressure before disconnecting any components or installing fuel pressure gauge. Ignition. If fuel pressure is greater than 60 psi (4.2 kg/cm 2 ) on CSI fuel system or 56 psi (4.0 kg/cm 2 ) on SFI fuel system, go to step 17). If fuel pressure is less than as specified, go to step 19). 16. Turn ignition off for 10 seconds. Turn ignition on. Fuel pump should operate for about 2 seconds. Observe fuel pressure. If fuel pressure is less than 60 psi (4.2 kg/cm 2 ) on CSI fuel system or 56 psi (4.0 kg/cm 2 ) on SFI fuel system, go to step 20). If fuel pressure is greater than as specified, go to step 28). 17. Check for restricted fuel line from fuel pressure regulator to point where fuel line was disconnected. If fuel line is restricted, go to next step. If fuel line is not restricted, go to step 23). 18. Repair restriction in fuel return line from pressure regulator to the point where fuel line was disconnected. After repairs, go to step 27). 19. Repair restriction in fuel return line to fuel tank. After repairs, go to step 27). 20. Check for restricted fuel line or fuel filter. If a problem is found, go to next step. If a problem is not found, go to step 22). 21. Repair or replace restricted fuel line or fuel filter. After repairs, go to step 27). 22. Turn ignition off. Connect a fused jumper wire between battery voltage and fuel pump test terminal. Slowly pinch fuel line return hose. Fuel pressure should increase to greater than 66 psi (4.6 kg/cm 2 ) on CSI fuel system or 62 psi (4.4 kg/cm 2 ) on SFI fuel system. If fuel pressure increases to greater than as specified, go to next step. If fuel pressure is less than as specified, go to step 24). 23. Replace fuel pressure regulator. After repairs, go to step 28). 24. If fuel pressure is less than 60 psi (4.2 kg/cm 2 ) on CSI fuel system or 56 psi (4.0 kg/cm 2 ) on SFI fuel system, go to next step. If fuel pressure is greater than specified, go to step 28). 25. Check for faulty fuel pump, partially disconnected fuel pulse dampener/pulsator, partially restricted fuel pump stainer or incorrect fuel pump. If a problem is found, go to next step. If a problem is not found, go to step 28). 26. Repair or replace fuel pump, partially disconnected fuel pulse dampener/pulsator, partially restricted fuel pump strainer or incorrect fuel pump. After repairs, go to next step. 27. Replace fuel feed/supply line. After repairs, go to next step. 28. Using scan tool, select DTC, CLEAR INFO function. Attempt to start engine. If engine starts and continues to run, go to next step. If engine does not start, or starts and stalls/dies, go to step 2). 29. Warm engine to normal operating temperature. Using DTC, select DTC, FAILED THIS IGN function. If any DTC(s) are displayed, diagnose and clear DTC(s). See the TESTS W/CODES article. If DTC(s) are not present, go to next step. 30. Using scan tool, select CAPTURE INFO, REVIEW INFO function. If additional DTC(s) are stored, diagnose and clear DTC(s). See the TESTS W/CODES article. If DTC(s) are not present, system is okay. CAUTION: DO NOT allow fuel pressure to exceed 75 psi (5.3 kg/cm 2 ).
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Friday, April 3rd, 2009 AT 2:16 AM

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