Possible fuel pump problem.
Possible fuel pump problem. Guys just did a head, cam, intake, and injector swap. I tried turning the car over just to get fuel up too the fuel rails. No luck. All fuses and relays are all checked out and no problems. No problems with the car before the swap. Is there a way to check the pump out to see if that is the problem before I replace it. When I turn the key on, I do not here the prime. What can I check???
Jay
Guys today lower the gas tank. and on top I checked the fuel sensor and had power. Then I checked the fuel pump connection on top at the other sensor and had no indication of power. I cycle the key several times and no luck with the power. I'm sure there should be power on both of the sensors? So I'm asking is there power to that sensor? and if so where does the power source come from? I'm guessing the PCM.
Also question about the junction box in the rear of the car where your electrical connectors are connected for your all of the sensors on top of the fuel tank. What pins should be hot? I currently only have 1 pin going to the fuel tank sensor element hot and all others are cold.
Problem fixed: Had a friend come over and fix it right up. Fuel pump was bad replaced it and working within an hour. Thanks to all for the help and advice. If I see you out sometime the beers on me....
Jay
Guys today lower the gas tank. and on top I checked the fuel sensor and had power. Then I checked the fuel pump connection on top at the other sensor and had no indication of power. I cycle the key several times and no luck with the power. I'm sure there should be power on both of the sensors? So I'm asking is there power to that sensor? and if so where does the power source come from? I'm guessing the PCM.
Also question about the junction box in the rear of the car where your electrical connectors are connected for your all of the sensors on top of the fuel tank. What pins should be hot? I currently only have 1 pin going to the fuel tank sensor element hot and all others are cold.
Problem fixed: Had a friend come over and fix it right up. Fuel pump was bad replaced it and working within an hour. Thanks to all for the help and advice. If I see you out sometime the beers on me....
Last edited by Jay2002ss; Jul 3, 2010 at 10:40 AM.
Yes,
I tried starting the car, all componets turn eveything seems to be working and I disconnected fuel line at fuel rail and had no fuel. Checked all relays fuses. Everything seemed to be good. Could a pvc vaccum connection make any differents?
Jay
I tried starting the car, all componets turn eveything seems to be working and I disconnected fuel line at fuel rail and had no fuel. Checked all relays fuses. Everything seemed to be good. Could a pvc vaccum connection make any differents?
Jay
You should be able to hear the fuel pump prime every time when you turn the key to "run". I'd start checking wiring and such to see if its getting power. Perhaps in the process of your H/C install a harness got disconnected somewhere.
As the golden rule says, if it worked before you touched it, its probably something you did, so start there
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Verdad Gallardo Fixed the ground and put the intake and back on. Try to start and still no fuel to the injectors. What would be my next tasking. Replaced PCM or Fuel Pump? Have you guys ever been so madd you wanted to bet the windows out? Well i'am almost there.
No priming at all. When I disconnect the electrical connector from the pump sending unit and check for power it has no power. When I disconnect the fuel quanity sensor it has power to the connector.
12 Second Club
Joined: Nov 2005
Posts: 407
Likes: 1
From: Rockwall, TX
The power only stays on at the pump for 2-3 seconds, unless you have a scan tool to command the power to stay on.
Alldata has a 30 step process for diagnosing the fuel pump circuit.
This will take a while:
When the ignition switch is ON, the powertrain control module (PCM) activates the in-tank fuel pump. The fuel pump remains ON as long as the PCM receives the reference pulses from the ignition system. If there are no reference pulses, the PCM turns the fuel pump OFF after 2-3 seconds . The pump delivers fuel to the fuel rail and injectors. The fuel pressure regulator, located in the fuel tank, maintains the system pressure at 380-410 kPa (55-60 psi ). Excess fuel returns to the fuel tank. When the engine is stopped, a scan tool in the output controls function can turn ON the fuel pump.
Incorrect fuel system pressure results in one or many of the following symptoms:
Cranks but will not run
Cuts out, may feel like an ignition problem
Poor fuel economy
Loss of power
Hesitation
DTCs set
More to follow:
Alldata has a 30 step process for diagnosing the fuel pump circuit.
This will take a while:
When the ignition switch is ON, the powertrain control module (PCM) activates the in-tank fuel pump. The fuel pump remains ON as long as the PCM receives the reference pulses from the ignition system. If there are no reference pulses, the PCM turns the fuel pump OFF after 2-3 seconds . The pump delivers fuel to the fuel rail and injectors. The fuel pressure regulator, located in the fuel tank, maintains the system pressure at 380-410 kPa (55-60 psi ). Excess fuel returns to the fuel tank. When the engine is stopped, a scan tool in the output controls function can turn ON the fuel pump.
Incorrect fuel system pressure results in one or many of the following symptoms:
Cranks but will not run
Cuts out, may feel like an ignition problem
Poor fuel economy
Loss of power
Hesitation
DTCs set
More to follow:
12 Second Club
Joined: Nov 2005
Posts: 407
Likes: 1
From: Rockwall, TX
1. Perform Diagnostic systems check-computers and controll systems.
2. with the scan tool command the fuel pump on. Does it come on? (Y) intermittent condition (N) go to step 3
3. Command the fuel pump on and off. Do you hear a click? (Y) go to step 9. (N) go to step 4
4. Remove fuel pump relay. Hook a test light to the control circuit of the fuel pump relay and a solid vehicle ground. While comanding the fuel pump on and off, does the lamp turn on and off? (Y) go to step 5, (N) go to step 6.
5. Connect test lamp to control circuit and ground circuit of fuel pump relay. Command fuel pump on and off. Does the light turn on and off? (Y) go to step 21, (N) go to step 24.
2. with the scan tool command the fuel pump on. Does it come on? (Y) intermittent condition (N) go to step 3
3. Command the fuel pump on and off. Do you hear a click? (Y) go to step 9. (N) go to step 4
4. Remove fuel pump relay. Hook a test light to the control circuit of the fuel pump relay and a solid vehicle ground. While comanding the fuel pump on and off, does the lamp turn on and off? (Y) go to step 5, (N) go to step 6.
5. Connect test lamp to control circuit and ground circuit of fuel pump relay. Command fuel pump on and off. Does the light turn on and off? (Y) go to step 21, (N) go to step 24.
12 Second Club
Joined: Nov 2005
Posts: 407
Likes: 1
From: Rockwall, TX
6. Does the test lamp remain illuminated with each command? (Y) go to step 7, (N) go to step 8.
7. Test control circuit for short to voltage. Did you find and correct condition? (Y) go to step 29 (N) go to step 28
8. Test the control circuit for a short to ground. Did you find and correct condition? (Y) go to 29, (N) go to 22
9. Turn ignition on, engine off. Does the pump run continuously? (Y) go to 10, (N) go to 11.
10. Turn ignition off, remove fuel pump relay. Turn ignition on, engine off. Does the pump run continuously? (y) go to 23, (N) go to 27.
11. Is the fuel pump fuse open? (Y) go to 12, (N) go to 14.
12. Disconnect fuel pump jumper harness from body pass-through connector. Test supply voltage circuit of the fuel pump for a grounded circuit between the fuel pump relay and the body-pass through connector. Replace the fuel pump fuse if necessary. Did you correct the condition? (Y) go to 29, (N) go to 13.
7. Test control circuit for short to voltage. Did you find and correct condition? (Y) go to step 29 (N) go to step 28
8. Test the control circuit for a short to ground. Did you find and correct condition? (Y) go to 29, (N) go to 22
9. Turn ignition on, engine off. Does the pump run continuously? (Y) go to 10, (N) go to 11.
10. Turn ignition off, remove fuel pump relay. Turn ignition on, engine off. Does the pump run continuously? (y) go to 23, (N) go to 27.
11. Is the fuel pump fuse open? (Y) go to 12, (N) go to 14.
12. Disconnect fuel pump jumper harness from body pass-through connector. Test supply voltage circuit of the fuel pump for a grounded circuit between the fuel pump relay and the body-pass through connector. Replace the fuel pump fuse if necessary. Did you correct the condition? (Y) go to 29, (N) go to 13.
12 Second Club
Joined: Nov 2005
Posts: 407
Likes: 1
From: Rockwall, TX
13. Lower the fuel tank. Inspect fuel pump jumper harness for the following conditions, damage to harness, grounded circuit. Replace fuse if necessary. Did you find and correct the condition? (Y) go to 29, (N) go to 20.
14. Turn off ignition. Dissconnect fuel pump relay. Turn on ignition, engine off. Probe the battery voltage circuit of the fuel pump relay switch. Does the test lamp illuminate? (Y) go to 15, (N) go to 25.
15. Connect a 20A fuse jumper wire between battery voltage circuit of the relay and the supply voltage circuit of the fuel pump. Does the pump opperate? (Y) go to 21, (N) go to 16.
16. Disconnect fuel pump jumper harness from the body pass-through connector. Test the supply voltage circuit of the fuel pump for an open or for high resistance between the fuel pump relay and the body pass-through connector. Did you find and correct the condition? (Y) go to 29, (N) go to 17.
17. IMPORTANT: inspect the ground circuit for being tight, for corrosion on terminals, or for damage to the wiring harness. Test the ground circuit of the fuel pump for an open or high resistance between the body pass-through connector and ground. Did you find and correct the condition? (Y) go to 29, (N) go to 18.
14. Turn off ignition. Dissconnect fuel pump relay. Turn on ignition, engine off. Probe the battery voltage circuit of the fuel pump relay switch. Does the test lamp illuminate? (Y) go to 15, (N) go to 25.
15. Connect a 20A fuse jumper wire between battery voltage circuit of the relay and the supply voltage circuit of the fuel pump. Does the pump opperate? (Y) go to 21, (N) go to 16.
16. Disconnect fuel pump jumper harness from the body pass-through connector. Test the supply voltage circuit of the fuel pump for an open or for high resistance between the fuel pump relay and the body pass-through connector. Did you find and correct the condition? (Y) go to 29, (N) go to 17.
17. IMPORTANT: inspect the ground circuit for being tight, for corrosion on terminals, or for damage to the wiring harness. Test the ground circuit of the fuel pump for an open or high resistance between the body pass-through connector and ground. Did you find and correct the condition? (Y) go to 29, (N) go to 18.
Last edited by 91RS383; May 12, 2010 at 05:12 PM.
12 Second Club
Joined: Nov 2005
Posts: 407
Likes: 1
From: Rockwall, TX
18. Inspect for poor connections at the fuel pump jumper harness to the body pass-through connector. Did you find and correct the condition? (Y) go to 29, (N) go to 19.
19. Lower the fuel tank. Inspect the fuel pump harness for the following: dammaged harness, open circuit, a poor connection at the fuel pump connector. Did you find and correct the condition? (Y) go to 29, (N) go to 26.
20. Install all disconnected components. Install new fuel pump fuse. With scan tool turn ON the fuel pump. Is the fuel pump fuse open? (Y) go to 26, (N) go to intermitint conditions.
21. ( inspect for poor conections at fuel pump relay. Did you find and correct condition? (Y) go to 29, (N) go to 27.
22. Inspect for poor connections at the harness connector of PCM. Did you find and correct condition? (Y) go to 29, (N) go to 28.
23. Repair supply voltage circuit of the fuel pump for a short to voltage. Go to 29.
24. Repair the open fuel pump relay ground circuit. Go to 29.
25. Repair battery voltage circuit of the fuel pump relay. Go to 29.
26. IMPORTANT: before you replace the fuel pump, inspect for poor connections at the fuel pump and within the fuel tank. Replace the fuel pump. Replace the fuel pump fuse if necessary. Go to 29.
27. Replace fuel pump relay. Go to 29.
28. Replace PCM. Go to 29.
29. Operate the system in order to verify the repair.
19. Lower the fuel tank. Inspect the fuel pump harness for the following: dammaged harness, open circuit, a poor connection at the fuel pump connector. Did you find and correct the condition? (Y) go to 29, (N) go to 26.
20. Install all disconnected components. Install new fuel pump fuse. With scan tool turn ON the fuel pump. Is the fuel pump fuse open? (Y) go to 26, (N) go to intermitint conditions.
21. ( inspect for poor conections at fuel pump relay. Did you find and correct condition? (Y) go to 29, (N) go to 27.
22. Inspect for poor connections at the harness connector of PCM. Did you find and correct condition? (Y) go to 29, (N) go to 28.
23. Repair supply voltage circuit of the fuel pump for a short to voltage. Go to 29.
24. Repair the open fuel pump relay ground circuit. Go to 29.
25. Repair battery voltage circuit of the fuel pump relay. Go to 29.
26. IMPORTANT: before you replace the fuel pump, inspect for poor connections at the fuel pump and within the fuel tank. Replace the fuel pump. Replace the fuel pump fuse if necessary. Go to 29.
27. Replace fuel pump relay. Go to 29.
28. Replace PCM. Go to 29.
29. Operate the system in order to verify the repair.
