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Fuel pump relay location


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8 replies to this topic

#1 Turbone

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Posted 13 November 2010 - 04:47 PM

Trying to find out why my fp isnt working and I'm having difficulty locating the fp relay on my 85 Brat (no power to fp with key all the way on, no ecu).
Is it under the dash, or under the passenger seat?

#2 Yo'J

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Posted 13 November 2010 - 06:00 PM

Should be just above the hood latch...I've got two types, same shape, different color(blue, black) different pins- one is missing one or its scooted over one notch. I don't remember. My 87 brat's is light blue, 82 wagon is black.

#3 TomRhere

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Posted 13 November 2010 - 06:01 PM

No actual fuel pump relay, there's a Fuel Pump Control Unit, FPCU. Mounted on the kickpanel, above the hood release. Should be Black with a 6 place connector.

Works off disty signals saying that the engine is running, also feeds the choke power feed.

I'm not 100% convinced that it actually powers the fuel pump during cranking of the starter. Mainly 'cause the floatbowl should have sufficient gas in it to start the engine, therefore not really needing the pump to run, unlike a FI system.

GD has commented on many posts concerning this. So a search of FPCU and GD should get you some good info.

#4 Gloyale

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Posted 13 November 2010 - 06:03 PM

You should test for power ot the pump when cranking.

The FPCU (relay) won't send power though to the pump unless there is an ignition pulse (tach pulse)

The unit itself is attached to the drivers side kick panel, just above the hood release. 6 pin connector, has 3 diamond logo on it.

ONe of the wires(solid blue?) should get power with key "on"

The yellow wire should give a tach pulse.

The Blue/red wire is the Fuel pump wire and should get power whenever the Tach wire get's a pulse

Black is a ground.

#5 TomRhere

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Posted 13 November 2010 - 06:13 PM

Think all 3 of use summitted our replies at the same time, (even if the time stamp says otherwise). Had a major slow-down going when I hit the send button.

#6 Turbone

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Posted 13 November 2010 - 06:25 PM

Thanks guys, I did a search and found the info on the fpcu right after my post.
I hot wired the pump to make sure it works, it does. I started the car and it ran for a min, then died. The carb (Weber) is getting fuel, I can see it squirting into the intake. I might have to go back to my original assumption, that I have bad gas.
Who knows where the pickup is in the tank?
Front or back?
Heres my symptoms, they are quite strange...
Runs ok, until you stop or turn right. Then it dies :confused:
I already took the top off the carb to see if theres junk in it, its clean.
And I installed a new filter up front (no filter in the back).

#7 naru

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Posted 13 November 2010 - 07:08 PM

Heres my symptoms, they are quite strange...
Runs ok, until you stop or turn right. Then it dies :confused:.


Probably flooding.
Float too high?

Tank pick-up problem wouldn`t show up for a moment or two.
Bad gas would be bad on left turns too.

#8 Turbone

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Posted 13 November 2010 - 07:17 PM

Thats why I said its weird.
The problem showed up all of a sudden, out of the blue.
It acts like its running out of gas, not flooding.
Hmmm, just had a thought.
Wonder if my choke is closing?

#9 GeneralDisorder

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Posted 13 November 2010 - 09:07 PM

Might be distributor related - is the tach signal clean? Put a test light on the negative side of the coil. You might not be getting a clean tach signal to the FPCU and that might be part of the running problem and the fuel delivery - being electronic it could happen for no good reason and at any time. I've seen similar bad behavior from the carbed EA distributor modules.

GD




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