Hi there, I have a question about the wiring to the fuel pump on an 85 Brat with an EA81, carburated.

 

It just didn't start one day and I THINK I've traced it to lack of power to the fuel pump.

 

The Pump should be good. I tried putting another pump in and still wasn't getting fuel to the secondary filter under the hood. So I'm thinking it just isn't getting power. With a tester light, I'm not getting anything at the wiring connection at the pump, so I assume the only issue is it's just not getting power.

 

I have no idea where the wiring goes for the fuel pump. No other electrical issues that I've noticed, so I assume it is isolated to the fuel pump wiring only, but I don't know that for sure. 

 

What and where can I check wiring, fuses, anything? 

 

Thanks a bunch.

Howdy, the fuel pump only receives power when the engine is cranking. There is a little black box (sometimes blue) that controls the fuel pump power under the driver side kick panel. That's, more than likely, what needs replacing.

Awesome, thanks. That is exactly the info that I need. Yeah, I had someone cranking the engine when I was checking everything. 

 

Is that something that goes out often? Is it kind of its own fuse or something? Roughy how big is it (to know exactly what I'm looking for).

 

Thanks again. I really appreciate it. 

2-1/4" x 2"

 

It should have a little metal tab on it. Both of my brats (85/84) have the black, 6 six wire connector, box. As opposed to the blue 4 wire one.

Perfect thanks. I have the 6 wire black box as well it looks like. 

 

So, how to tell if it's bad or not?

 

numbering the posts 1 through 6, left to right, top to bottom:

 

With the key in the on position I get (with a test light) light on 2,4,and 5. When I crank it, 3 flickers a couple times. that's it. nothing out of 1 or 6.

 

Sorry for the lousy explanation. If you follow that at all, let me know what you think. I'm guessing its bad.

 

Thanks again. Sorry for all the questions on such a basic operation.  

If no one gets you that info; I'll get back to you tomorrow with it.

Does anybody know how to tell if this fuel pump control unit is bad or not?

 

Thanks

OK, I tried a different FPCU form a junkyard and still the same thing. I'm (sorta) ruling that out now, as well as the fuel pump itself. 

 

Any other ideas of what could be going on?

 

It hasn't had any fuel or starting problems at all. Just didn't start one day. No fuel at the inline filter/vapor separator under the hood. No power with a light tester at the connection by the fuel pump back by the tank. (all tested while cranking engine.)

 

Any ideas?

 

Thanks a bunch

Did one of the relays go out under the dash? Did it blow the fuse for the fuel pump? Is it getting power through the fuse for the fuel pump? Does it have a ECM? If you don't fill like doing a lot of trouble shooting I would recommend hooking the fuel pump to a toggle switch direct to the battery with a inline fuse.

Yeah I've checked most of that stuff. Is there another relay that would effect the fuel pump OTHER than the FPCU? and is there a fuse specific for the fuel pump other than in the fuse box?

 

This is what I've checked: No blown fuses, FPCU is good, and fuel pump is good. 

 

Thanks for the reply's 

 If you don't fill like doing a lot of trouble shooting I would recommend hooking the fuel pump to a toggle switch direct to the battery with a inline fuse.

 

This is very unsafe.  You don't want the fuel pump to run when engine is not  (like a crash or rollover)

 

 

Yeah I've checked most of that stuff. Is there another relay that would effect the fuel pump OTHER than the FPCU? and is there a fuse specific for the fuel pump other than in the fuse box?

 

This is what I've checked: No blown fuses, FPCU is good, and fuel pump is good. 

 

Thanks for the reply's 

 

Does the Tach needle jump while cranking?  If not then the FPCU won't see a pulse won't power pump.

 

Also did you get your replacement FPCU from another late (83+) EA81 car?  The early ones, and the EA82 ones are different

The tach just has a little bump right as i first begin to crank it, but then as I keep cranking it it just lays flat. I'm not sure what is normal though. Maybe you can help me out with that.  If that's the issue. what is next? coil? 

 

Also, I should mention that at this point the battery is barely cranking it. It's been cold and hasn't started in a week now but I keep cranking it to check other things. I don't know how much that would effect how much the tach moves at this point. It's time to have it jumped for any more testing I think. 

 

Thanks again, let me know what you think.

Forgot to add that the FPCU I got looked exactly like mine. I think it was an 86 with an EA81. I actually just took the circuit board out and put it in my plastic housing. the circuit board looked the same as mine anyway so I'm pretty sure it's the right one.

Hey Bratlife did you ever figure out your issue? I just had the same thing happen to me yesterday with my 86 hatchback. Was driving around the block & all of a sudden it dies. No more power going to the pump ... checked all my connections etc.