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Old 03-15-2016   #1
aafc
 
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Join Date: Feb 2010
Location: Ochlocknee, GA
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Default Fuel pump relay #1

Any tips on replacing fuel pump relay #1 on relay rack RH side of car?
Had someone help me test fuel pressure, (have to get longer fuel pressure
hose). He noted that fuel pressure dropped low just before motor quit
running. fuel pressure relay #1 failing after motor goes into closed loop,
causing pressure to drop? Still looking for answers.

Thanks
John
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Old 03-16-2016   #2
QB93Z
 
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Location: Westminster, Maryland
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Default Re: Fuel pump relay #1

The fuel pump relays are behind (above) the passenger side hush panel. There are five or six relays there and it was hard for me to ID which was the FP1 relay.

In my recent experience, there have been many more fuel pump failures and not many relay failures. My fuel problem last summer at Mt McKinley was a failed wiring connector in the fuel tank.

Good luck

Jim
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Old 03-16-2016   #3
aafc
 
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Default Re: Fuel pump relay #1

I think you are right. That relay is the 3rd from right of relay rack and is not
easy to get to. I'am going to replace the pri pump first , then go from there.
Thanks
John
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Old 03-16-2016   #4
RussMcB
 
Join Date: Jan 2015
Location: Marietta, GA USA
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Default Re: Fuel pump relay #1

A thought: Temporarily bypass the relay, provide switched 12v to the pump, then test monitor fuel pressure. That will tell you if the problem is the pump, or the electronics to it.

The PO of my car was struggling with pump issues and he did that. It was handy for testing each pump. Also handy is a fuel pressure gauge mounted on the a-pillar.
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Old 03-17-2016   #5
aafc
 
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Default Re: Fuel pump relay #1

Went back to fuel pump testing. Had a 4 ft fuel pressure hose made up so
i could see if fuel pressure drops from inside car. The fuel pump in car (PRI)
was replaced when this tbl started. Start car open loop ok when it went to closed loop after about 5-8 min fuel pressure drops to 20 lbs and car stalls.
OK replaced PRI fuel pump and restarted car, open ok - closed loop ok.
Ran car for 20 min. no fuel drop steady at 43 lbs. Now did i fix the tbl?
Ok so to prove the first PRI pump is bad i reinstalled the org. pump
restarted car and car ran the same open loop ok- closed loop 4-8 min fuel pressure drops and car stalls. I then removed the PRI pump that failed and
rpl it with the new one.
Reran the test again no trouble. over kill on the testing don't care did it
to prove that the first pump was defected from the start. Its going back
and i'll get a new one.
If i had no help the first time i would not have seen the fuel pressure drop.
So the right tools or someone to help i would not have fixed this tbl.
thanks for your support and helpful hints.
John
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Old 03-17-2016   #6
QB93Z
 
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Default Re: Fuel pump relay #1

Good Job! Glad you got it sorted out.

Jim
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