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Fuel pump fuse keeps blowing:( Bad fuel pump?

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Old 07-01-2014 | 05:18 PM
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Default Fuel pump fuse keeps blowing:( Bad fuel pump?

Hello All,

Need your expert help again!
Yesterday my 86na stalled out and couldn’t get her started again.
I think I heard a loud noise coming from the rear passenger side a few days ago, hmmm..

I put the 3 wire jumper into the relay location -#30 #87 #87b
And again this caused the fuel pump fuse to blow!

I connected the fuel pump directly to battery and the car did start, but it stalled out. The fuel pump was very a bit noisy, and whinny. I am thinking this is a sign it is dying?

I ordered a new:
fuel pump
DME relay
reference sensor

The connector head on the reference sensor crumbled into tiny pieces. Seems this may be part of the problem too!

Question: Does any one have a part number for the short 2 wire fuel pump harness?
I am looking for the small length section that plugs into the fuel pump while the other end plugs into the longer harness that travels to the front of car



T.I.A.
Toran

Last edited by Toran; 07-01-2014 at 05:26 PM. Reason: more info
Old 07-01-2014 | 09:05 PM
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Yeah, it sounds like the pump has gone south on you. Don't forget to change the fuel filter and pull the strainer to see that it's clean (it's in the tank where the fuel line is attached). If you pull the line off the tank and the fuel really pours out, your strainer should be ok. I'd recommend that your tank is as empty as possible or you're gonna have gasoline everywhere. Make sure your garage door is open or you're outside and have a fire extinguisher handy.
Old 07-01-2014 | 09:46 PM
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Unplug your O2 sensor before you pull the pump. It is on the same fuse. For some reason the sensor side of the sensor plug just falls apart over time, replace them both.
Old 07-01-2014 | 11:11 PM
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Thank you for the responses!

mytrplseven, good tip. I replaced the fuel filter and strainer about 8 months ago.
And yep I just filled the tank up too! Gonna need something to catch all that premium fluid!

Adker, another good tip, much appreciated!
Old 07-05-2014 | 05:48 PM
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Just had a holiday brain freeze!
The fuel pump has a green/black wire and a brown wire

The brown is negative?
Old 07-05-2014 | 06:08 PM
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Yes, it is.
Old 07-05-2014 | 06:21 PM
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Originally Posted by Toran
And yep I just filled the tank up too! Gonna need something to catch all that premium fluid!
You shouldn't be putting premium in an N/A, they are not tuned for it from the factory. 87 octane is what they call for.
Old 07-05-2014 | 07:51 PM
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I put 87 in many years ago and it ran rough, stalled and knocked terribly!
Old 07-06-2014 | 02:34 AM
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Originally Posted by Adker
Unplug your O2 sensor before you pull the pump. It is on the same fuse.
Toran, have you looked over your O2 sensor harness to make sure it hasn't come into contact with anything hot, chafe/melt, and create a short on that circuit?
Old 07-06-2014 | 04:50 AM
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Originally Posted by Toran
I put 87 in many years ago and it ran rough, stalled and knocked terribly!
Then something is wrong, even the 10.6:1 euro N/A's run fine on 87.
Old 07-08-2014 | 03:20 PM
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Hello again,

Could use some more of that good forum support again

I replaced:
fuel pump
DME relay
distributor cap and rotor
reference sensor


Reference sensor tach bounce when attempting to start the engine
And the car still will not start. It will not turn over
The fuel pump fuse still keeps blowing.

What I have tried:
Fuel pump connected directly to battery you can hear it working and the fuel rail has pressure.
3wire jumper to 30-87-87b DOES NOT CAUSE THE NEW PUMP TO START

And still it will not start.

I have noticed that when using the 3wire jumper it is number 87b that causes the fuse to blow.

What am I missing?

Last edited by Toran; 07-08-2014 at 06:59 PM. Reason: more info added
Old 07-08-2014 | 03:23 PM
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The ICV is on the fuel pump circuit in the early cars, not sure about the late ones. I had the same issue and disconnecting the ICV got me going again.
Old 07-08-2014 | 03:25 PM
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Originally Posted by konakat
The ICV is on the fuel pump circuit in the early cars, not sure about the late ones. I had the same issue and disconnecting the ICV got me going again.
Thanks konakat, I'll give it a try!
Old 07-09-2014 | 01:11 AM
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Originally Posted by Toran
And the car still will not start. It will not turn over.
If it won't turn over, you should look at the power/ground leads to the starter.

Have you checked the wiring to the O2 sensor for short circuits?
Old 07-11-2014 | 09:47 AM
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Hello Everyone,

AS ALWAYS, THANK YOU VERY MUCH FOR THE MUCH NEEDED TECH SUPPORT.

Looks like the issue was related to the wiring going from the full pump to the fuse box. I tried tracing the wires from the fuel pump toward the front of the car and lost them in the process.

Cause I needed to get back up and running(going to work). I was able to put the fuel pump on a LED toggle switch connected directly to battery. That got me up and running for sure without any problems.

This weekend will continue the hunt to replace the wiring.
At the same time that fuel pump toggle switch setup can be made to be a cool anti-theft setup too!

THANK YOU

Last edited by Toran; 07-11-2014 at 09:47 AM. Reason: more info added


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