 Fuel Pump wont run off relay board... |
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| D1A3 |
  Jul 17 2010, 06:30 PM
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Gruppe Neun Vierzehn Südosten  Group: Members Posts: 362 Joined: 3-June 04 From: Atlanta, GA Member No.: 2,152 Region Association: South East States  |
Car died a few weeks ago while driving it and I think I know what is causing it...
Turns out, my fuel pump was not getting power. I temporarily rigged up the pump to run off my driving light relay and the car runs great. I traced the harness power wire (black/red stripe) back all the way to the relay board and could not find any break/melting or anything suspect. I found in the Haynes Manual that the fuel pump relay should have voltage at 86 and ground at 85. Guess what? I checked and have voltage at 86, but NO ground at 85. The manual says in this case to check the "main relay." What the heck is that? It references the "fuel pump relay" in other places uniquely, so wondering what a "main relay" is on our cars. Also, mentions that there could be an open circuit causing the ground to fail. What should I check? The relay being used is known to be good, so any ideas or am I looking at replacing the relay board? Thanks everyone! |
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| swl |
Jul 18 2010, 07:21 AM
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Senior Member Group: Members Posts: 1,409 Joined: 7-August 05 From: Kingston,On,Canada Member No.: 4,550 Region Association: Canada |
disconnect the 4 pin connector and jump Pin III to ground. (you are doing what the ECU normally does) Key on. Does the pump run?
If yes then you may want to disconnect the harness from the ECU and inspect the condition of the contacts. Clean as necessary. Reseat the connector and try in normal mode (4 pin connect plugged back in). Remember that the pump will only run for a second or two at key on. Then it shuts down until you start cranking. If no do you have power at pin 30 of the fuel pump relay? |
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Posts in this topic
D1A3 Fuel Pump wont run off relay board... Jul 17 2010, 06:30 PM
904svo Jason, that ground on pin85 comes from the ecu har... Jul 17 2010, 06:36 PM D1A3 Thanks Larry. Going to check that now.
BTW: I... Jul 17 2010, 07:53 PM D1A3 Larry,
Checked the grounds that are just on the p... Jul 17 2010, 09:26 PM Cap'n Krusty Two words of advice: "wiring diagram". ... Jul 17 2010, 10:53 PM SLITS Check the main gorund bundle, near relay board on ... Jul 18 2010, 08:18 AM ahdoman Also, don't forget the two fuses on the board ... Jul 18 2010, 04:25 PM blitZ Did you try swapping out the fuel pump relay on th... Jul 19 2010, 07:41 AM D1A3 OK, Just FINALLY completed a permanent fix for the... Feb 20 2011, 05:44 PM
markb Glad you figured it out. I had a relay board that ... Feb 20 2011, 06:11 PM |
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