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power to fuel pump


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I swear its the curse of the 1988 Subarus!!!! :madder: Same type of bull happens on my 88 GL wagon. SOmething breaks, I fix what broke, go to start her up and something completly irrelivante broke JUST SITTING THERE!

 

I wish I had a better suggestion to this issue other then "ive been there and dont give up" :D

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Hah...that happened to me with my '88 GL Wagon too. I had just finished replacing the clutch, which was the biggest job I'd ever performed on a vehicle up to that point, and while driving it for the first time with the new clutch, I realized that I had a blown head gasket. It ran just fine before the clutch job, but right afterwards, it ran really rough--I'm not sure how it blew just sitting in the driveway. Just my luck, though. :D

 

BTW Steve, there is a relay under the dash somewhere, but I'm not sure where--I've never had to mess with mine. Wait, here it is in a thread from a few days ago.

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I checked the relay above the ECU. It clicks in when the ignition is turned on. I'm thinking its the ECU. I read about someone who changed out a transistor in the ECU and everything started working normally. I would like to know which transistor. I've got the ECU apart on my bench and have no idea where to look. HELP!

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Just a few thoughts. The fuel pump should be energized briefly when you first turn the ignition on but it doesn't actually run continuously till the car is at least cranking over or running. There are two seperate circuits that can power the pump Do you have fuel pressure? If so then the pre-start circuit is working and the wiring to the pump as well as the pump are OK. The ECU does control the continuous operation of the pump once you start cranking the motor. Silly question would be whether your disty is plugged in because thats where the signal comes from that tells the ECU the motors spinning.

 

So

1)Test for power and ground at the pump when you turn the key on(it only lasts a few seconds)

2)Test for power and ground with the motor crankin

3)Hotwire the pump to test function. If the pump won't spin try reversing polarity as they can get bound up with sediment and assorted crap. Reversing the power reverses the pump and back flushes it(takes a few cycles).

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Thanks for the info. I haven't had an assistant to try for power when the key is turned on or engine cranking but, I did hot wire the fuel pump. It works fine. Not sure which way its spinning the right way though. I spun it in both directions. Next, (if I don't find an assistant) I'll hot wire the pump and try starting the car. Can't wait to hear the SOB (I mean sooby) run.

 

Still would like to know which transistor to changeout in the ECU if necessary.

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Check for codes on the ECU. This is, like someone said above, heavily related to the distributor. I believe if you do the green, double bladed connector for the ECU you should hear the pump run. For that matter do you hear the pump when you initially turn the key? For 5-7 sec or so? BytheSea is close to the money shot.

 

 

 

Jay

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You can make a cheap test light out of any bulb holder and a few feet of wire. If you want to be super ghetto pin the wires from your tester to the fuel pump wires with sewing pins :eek:

This will let you see if the circuits working while sitting in the comfort of your drivers seat :D

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I've never been schooled on reading the codes. How do you do it and what will it tell me?

 

As far as listening for the fuel pump, I don't hear it. Had the wife turn the key on while I was down listening. Even tried my Sooby that runs and didn't hear the fuel pump. However, I didn't listen while cranking.

 

How can I tell which way to hot wire the pump so I know its pulling? I may have heard it making bubbles in one direction, I could pursue that again.

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I've been having this trouble with my 4wd Wagon. It actually left me stranded this evening. I eventually just hot wired it and ran a toggle switch for it also. Good anti-theft device :D. Next step: lighted blue (to match the interior) toggle switch mounted on a turned aluminum panel. :)

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