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New brat owner needs help!


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Hey guys nice to meet you all. First of all thanks for all the info you have shared....it has helped a lot already. So I just got a great deal on 2 brats, a 85 and 86. Both are decent shape but have sat for awhile and each have their issues. I wanna get them both going instead of a Frankenstein scenario if possible.. So right now I'm dealing with a fuel issues on the 85. I have read several threads out the fpcu and whatnot but I'm kind of stuck..... Car whens fine when fuel is poured in carb, test light shows power while cranking at fuel pump wiring harness, no sign of power or suction at either end of the fuel pump when trying to start. Fuel pump is brand new. So it seems like it is getting power to the pump but no function from the pump. So like I said I'm kinda stuck....grounding issue? Please help. If any pictures or more description would help please let me know. 

P.S. I have been looking into these things for a while so I'm super excited to get them going and have some fun with them. I'm sure I will have a ton more questions, so thanks in advance for you advice and patiance, I'm sure I will owe some of you guys more than a few beers by the time its said and done. 

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The fuel safety cut relay is under the dashboard above the driver’s feet. In my brumby/brat it’s a black unit. 

This could be disconnected or have a kill switch incorporated into it. I don’t know that it’s negative switching or not. If it was positive switching you wouldn’t see any voltage at the pump. 

The other thing it could be is a blocked fuel pipe. Used compressed air to blow any crud from the front to the back of the car - disconnect the flexible fuel lines so you’re not blowing crap into your new pump. 

If the car won’t start after this, you could manually apply 12v and earth to make the pump run, then try starting. If it starts then you know for sure you have a wiring issue to sort out. 

Have fun, these little utes are real gems! 

Cheers 

Bennie

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My Brumby is positive switched when ignition first on for few seconds, then once engine is running

Old fuel ....do not even try to use it or its tank until you know tank is clean inside

Fuel is a complex makeup that when stale, chemicals have evaporated out if it into the air space in tank. Leaving a full fuel tank for years seems to be better than less

This changed fuel rots plastics and rubbers, causes gumming of intake valve stems....

I have cleaned each section of fuel pipes with compressed air and had some good crap  rust coloured stuff low out resolving all similar issues

Once you wire up pump, run some new temporary hose to each end and see if it pumps it through from one safety approved container to another in a safe environment with an assistant and observer standing by...bench test the pump

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8 hours ago, el_freddo said:

The fuel safety cut relay is under the dashboard above the driver’s feet. In my brumby/brat it’s a black unit. 

This could be disconnected or have a kill switch incorporated into it. I don’t know that it’s negative switching or not. If it was positive switching you wouldn’t see any voltage at the pump. 

The other thing it could be is a blocked fuel pipe. Used compressed air to blow any crud from the front to the back of the car - disconnect the flexible fuel lines so you’re not blowing crap into your new pump. 

If the car won’t start after this, you could manually apply 12v and earth to make the pump run, then try starting. If it starts then you know for sure you have a wiring issue to sort out. 

Have fun, these little utes are real gems! 

Cheers 

Bennie

Hey I thought this might be the problem as well so I already did disconnect the line from the tank that runs to the pump and blow air through it and air came out with no problem at all going to the pump so I know it's not obstructed from tank to pump. I read up on that relay and assumed if I was getting voltage at the fuel pump connector that wouldn't be a problem is that incorrect?

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8 hours ago, el_freddo said:

Further thought: check for spark. If you’re not getting any spark, the fuel cutout relay does not power up the fuel pump after an initial prime of 3-5 seconds. 

Cheers 

Bennie

If I pour gas directly in the carb it will start and run fine so I'm assuming it's not a spark problem. As long as I keep feeding your gas it keeps running.

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3 hours ago, Steptoe said:

My Brumby is positive switched when ignition first on for few seconds, then once engine is running

Old fuel ....do not even try to use it or its tank until you know tank is clean inside

Fuel is a complex makeup that when stale, chemicals have evaporated out if it into the air space in tank. Leaving a full fuel tank for years seems to be better than less

This changed fuel rots plastics and rubbers, causes gumming of intake valve stems....

I have cleaned each section of fuel pipes with compressed air and had some good crap  rust coloured stuff low out resolving all similar issues

Once you wire up pump, run some new temporary hose to each end and see if it pumps it through from one safety approved container to another in a safe environment with an assistant and observer standing by...bench test the pump

I thought that may be a problem as well so before I did anything I drained all of the old fuel out of the tank and put in some new ethanol free gas. I also replaced all the rubber hoses that hook up right at the fuel pump just to be safe. The pump is brand new so I have not bench tested it but I assume I just hook up a hot lead and ground from a battery and the pump should run correct?

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45 minutes ago, naru2 said:

Bad ground,if you have 12V while the harness is connected to the pump.

Run a jumper to battery negative for a test

so this is what I was thinking probably some small stupid electrical thing I can't figure out. I haven't been able to discern does this thing ground on the bracket the fuel pump is mounted on? On my bracket there is a small ground wire attached to the bracket screw. This looks like it may have been added after the fact but I'm not sure. I read somewhere you can ground from the frame like this and attach the other end of the wire to the fuel pump body. I did try to ground on the bracket and with the wire attached to the bracket and it didn't seem to make a difference. I will try to run a wire directly from the battery negative terminal and see if that works. Do you know how these fuel pump are supposed to be correctly grounded?

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47 minutes ago, naru2 said:

Bad ground,if you have 12V while the harness is connected to the pump.

Run a jumper to battery negative for a test

Also just FYI when I was testing the fuel pump connector I used a test light connected to the ground bolt on the bracket and it grounded good enough to light up test light when I touch the terminal while cranking. Is there supposed to be exactly 12 volts to the hot terminal? I just used a test light not a voltmeter. I was assuming in that connector one is the hot and one is the ground? I only had voltage on one lead.

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1 hour ago, Wannabebrat said:

Also just FYI when I was testing the fuel pump connector I used a test light connected to the ground bolt on the bracket and it grounded good enough to light up test light when I touch the terminal while cranking. Is there supposed to be exactly 12 volts to the hot terminal? I just used a test light not a voltmeter. I was assuming in that connector one is the hot and one is the ground? I only had voltage on one lead.

 

Yes,Should be very close to battery voltage.

My test light lights up at less than 5 volts.You need a meter.

If less than 12V,then bad connections or FPCU.Pump should run w/9-10 volts though.

If the jumper wire to negative does not work,put a fuse on the battery end and jump power to the pump for a test.

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2 hours ago, naru2 said:

 

Yes,Should be very close to battery voltage.

My test light lights up at less than 5 volts.You need a meter.

If less than 12V,then bad connections or FPCU.Pump should run w/9-10 volts though.

If the jumper wire to negative does not work,put a fuse on the battery end and jump power to the pump for a test.

Okay I'll check the voltage here shortly. I know those relays are hard to find for replacement is there any aftermarket ones that would work?

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4 hours ago, Wannabebrat said:

Also just FYI when I was testing the fuel pump connector I used a test light connected to the ground bolt on the bracket and it grounded good enough to light up test light when I touch the terminal while cranking.

Was the fuel pump connected when you did this test? Using a test light, there must be a load on the circuit.

If not, hook up a headlight bulb or a fan motor to the connector and ground. If it works, then you know you have good voltage and current at the connector and that leaves the pump questionable. If the light is dim or the motor runs slow or not at all, then there is a problem upstream like relay contacts or another connector or even dirty fuse contacts.

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21 hours ago, Wannabebrat said:

Okay I'll check the voltage here shortly. I know those relays are hard to find for replacement is there any aftermarket ones that would work?

Here is one  https://www.opgi.com/air-fuel-delivery/fuel-pumps-regulators/electric-fuel-pump-controller2/fuel-pump-controller-all-12-volt-ch30173.html

Or,if you do not mind eliminating the engine stops/pump stops safety function(I did),just use a normal relay.

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On 3/19/2020 at 4:24 PM, Rampage said:

Was the fuel pump connected when you did this test? Using a test light, there must be a load on the circuit.

If not, hook up a headlight bulb or a fan motor to the connector and ground. If it works, then you know you have good voltage and current at the connector and that leaves the pump questionable. If the light is dim or the motor runs slow or not at all, then there is a problem upstream like relay contacts or another connector or even dirty fuse contacts.

Ok so update....I hooked the fuel pump up to directly to the battery with a 15amp fuse in the hot line and BINGO!! pump ran fine...car started and ran fine for awhile. SO thanks again for the help so far. I checked and I have 8-9 volts coming into 2 or 3 different leads on the wiring harness that connects to the fpcu. So now that the pump and all work I'm assuming it has to be the fpcu since there is voltage coming into the harness with the switch on ..would that be correct? I don't mind paying 70 bucks for the relay listed above so everything works correctly....but is there anything else I need to check first just to make sure its the relay? If I do get that relay (and figure out how to hook it up) what would I be losing if I use a cheaper 6 pin relay like this one? https://www.amazon.com/Standard-Motor-Products-RY56-Relay/dp/B000C7ZVH8  Would something like this even work? I hear "just add a relay and bypass" it a lot but I don't really know where to add it and what it needs to hooked to and how.I have no problems following directions when it comes to electrical but figuring it out on my on is not my strong suit so forgive my ignorance. Any direction would be much appreciated. 

 

Thanks!

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Ok so update....I hooked the fuel pump up to directly to the battery with a 15amp fuse in the hot line and BINGO!! pump ran fine...car started and ran fine for awhile. SO thanks again for the help so far. I checked and I have 8-9 volts coming into 2 or 3 different leads on the wiring harness that connects to the fpcu. So now that the pump and all work I'm assuming it has to be the fpcu since there is voltage coming into the harness with the switch on ..would that be correct? I don't mind paying 70 bucks for the relay listed above so everything works correctly....but is there anything else I need to check first just to make sure its the relay? If I do get that relay (and figure out how to hook it up) what would I be losing if I use a cheaper 6 pin relay like this one? https://www.amazon.com/Standard-Motor-Products-RY56-Relay/dp/B000C7ZVH8  Would something like this even work? I hear "just add a relay and bypass" it a lot but I don't really know where to add it and what it needs to hooked to and how.I have no problems following directions when it comes to electrical but figuring it out on my on is not my strong suit so forgive my ignorance. Any direction would be much appreciated. 

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Progress!

Do you have 12 volts on any of the FPCU wires?

If not,the FPCU is not the problem.

There are 2 seperate 12 volt feeds to the FPCU.One is live w/the key in ACC position and RUN position.The other only in RUN,

One of the blacks is hot in RUN,the other is ground.

Might be a bad ignition switch or corroded connector.

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10 hours ago, naru2 said:

Progress!

Do you have 12 volts on any of the FPCU wires?

If not,the FPCU is not the problem.

There are 2 seperate 12 volt feeds to the FPCU.One is live w/the key in ACC position and RUN position.The other only in RUN,

One of the blacks is hot in RUN,the other is ground.

Might be a bad ignition switch or corroded connector.

Ok so now that you mention it there is something going on with the switch. When you turn it over hard it won't engage the starter. Kind of like there is a bad or faulty spot. When you hold it just right and turn gently it will turn over fine. But I defiantly wasn't getting a full 12v at fpcu harness with key on. So I assume now I make sure there are 12v coming into the switch and if so replace it? 

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If the switch is wonky,you need a new one regardless of anything else.I had to replace mine recently.

Should be 12 volts on the thick white power feed wire all of the time.IG terminal (black) should be 12 volts in RUN.Blue will be hot in RUN or ACC.

If there is less than 12 volts on the white,check voltages on both sides of the fusible links near the battery..

 

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Ok so I think I have it figured out...wanna see what you guys think. Complete newb brain fart....keep in mind this is my first brat and I'm no expert mechanic by any means. So while checking the switch for voltage I noticed the damn switch wasn't even in the right place. A hole had been cut in the kick panel and some "other" switch added in.... looked over on the column, and sure enough empty switch housing. :banghead: So it all started to come together. So the quick run though: on tinkering with the fuel pump I noticed a red and black wire ran from pump location all the way up to the  batt area...both ends were hanging connected to nothing...there was no fuel pump when I got it. Then when I noticed the switch, I uncovered some Electrical tape around the white and black wires above the pink harness, once I removed the tape there were two smaller wires spliced in that were clearly connected to something that was missing. A few other things made it click....I think. The original switch went out, previous owner replaced it with a different switch with no tach wire setup so no power was supplied to the fpcu. So then they put a toggle type thing off the switch wires to turn on the pump manually and hooked up the pump straight to the battery. I found a blue and yellow wire running from the original switch housing to a green connector with yellow and black/white stripe wire on the other end.....just like the ones that come off the coil. So I thinking I get a new OEM style switch and it will be all grits and gravy....fingers crossed anyway. I will attach pics.  Any idea where I can get one of these switches? I haven't been able to find one yet. 

Also Naru2 I did check the switch and got the voltages you described but I'm assuming this switch is not serving the tach/coil function thing that sends power to the pump?? 

On a side note I couldn't help my self from hot wiring the pump up again and letting her run a little...I'm super pumped! other than a few small things everything seems to be in pretty good shape and road worthy. I'm sure some small stuff will come up, but I got all new rotors and brakes except for the calipers and drums (which seem hard to find). Also picked up some new stock size tires for now until I can get it lifted. :rolleyes: 

As always thanks again for all the help...couldn't have made it to this point with out all you guys tips and suggestions.:headbang:

Pics:

https://photos.app.goo.gl/bH53Nrk4wk1uJvKj9

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Something I find with Subaru wiring is likely due to its earth switching

If I am going to tap into an existing power for say air horn compressor off coil horns I use the POS and neg sides of circuit to switch new devices relay

Being LPG only I don't use the fuel pump but recently used fuel pump connector pos and neg to supply engine running only power up circuit to drive my trailer LED lights as the rear indicators only have 8.6V not enough to drive 12V trailer lights.

 

Using pumps yep 12V supply gave no troubles

Edited by Steptoe
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The ignition switch does not switch the tach signal to the FPCU.

Your test light should pulse while cranking w/it is on the yellow FPCU wire.

You need 12V at the FPCU.

The switch in your link is an ea82 switch.They only have one mounting hole and may be otherwise different.

Rockauto has ea81 switches.Tilt wheel switches w/a short harness are NLA.You need to cut the tabs off a normal one and solder wires on like I did.

Edited by naru2
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