fuel system help

[meats50]

I wasnt sure on where to post this so if its in the wrong forum I apologize.

So I am doing an 03 swap into my 1992 notch. I used everything from the cobra as far as wiring goes. I already had an aeromotive a1000 fuel system on the car from my previous setup, so I decided to keep that. So basically consider these questions to be about an 03 cobra with an aeromotive a1000 fuel system. Although I used division x fuel rails from lethal instead of the aeromotive pieces.

I wired the fuel system as per the instructions on the aeromotive website. I primed the pump till I seen fuel pressure. I set base fuel pressure to 38lbs. Then attached my vacuum line. I will be getting the car professionally tuned once everything is back together.

The car cranked and started just like a stock cobra would. Throttle response seems good etc.

My concerns are that it sounds like the computer is decreasing/increasing pump voltage. Is it supposed to do this? Ill have to go back through my wiring diagram, but I thought the signal wires that actually controlled this were seperate from the 12v constant key on power I used. Ive read a few places that this will burn these style pumps up. Then ive read guys wire them thru the fpdm and run a controller. Im just wanting to know the proper way of running this style system. As I dont want to keep buying pumps trying to figure it out on my own. I plan on calling aeromotive, but its friday which means monday would be the soonest and im impatient haha.

Ive done a few searches but couldnt find the specific answers I was looking for. So any help you could provide is greatly appreciated:beer:

 

[foxman92]

if you have the pump wired to a 12v power with key on, and it stays running the whole time key is on.. it will work fine, but you will need the speed controller from aeromotive, this will increase/decrease the pump during normal street driving, which means it will lower the voltage to pump when your in traffic and going slow etc.. and apply full power when you reach a certain rpm..

NOTE its over $300 for the aeromotive controller.. that is the reason i got rid of the aeromotive pump setup, that and running E85 i would have been border line on maxing it out..

 

[Brutal Metal]

I'd ditch that Aero setup! You running the stock tank sumped?

 

[meats50]

Ill call aero monday and check into the controller.

Yes im running a stock tank with a sump. I used the aeromotive kit because
1. it was already on the car
2. I have a kb 2.8 on the shelf i intend on putting on the car this winter. I felt why install the stock system then end up buying alll new pumps etc when I already have the aero set up.

So the everythings in and works. just wana make sure im not gona burn the pumps up.

 

[meats50]

So I figured out my issue. I wasnt real familiar with the fpdm. I thought I had bypassed it By running just the 12v keysource power from the pump harness. I didnt realize till today that this wire enters and exits the fpdm before going down to the pump. I had assumed (incorrectly) that the wire labeled (signal) was the wire that controlled voltage to the pumps.

So what i have to do is get my tuner to change the value in the computer to zero so that it reads it as a return style system and then wire around the fpdm. Then the pump will receive its constant 12v power and the fpdm wont be changing the voltage like it is now.

The wires I used to wire my relay were brown/pink (+) and black/red (-). Which are the correct wires. Once I do the rest as I stated above everything should work great :thumbsup:

 

[foxman92]

So I figured out my issue. I wasnt real familiar with the fpdm. I thought I had bypassed it By running just the 12v keysource power from the pump harness. I didnt realize till today that this wire enters and exits the fpdm before going down to the pump. I had assumed (incorrectly) that the wire labeled (signal) was the wire that controlled voltage to the pumps.

So what i have to do is get my tuner to change the value in the computer to zero so that it reads it as a return style system and then wire around the fpdm. Then the pump will receive its constant 12v power and the fpdm wont be changing the voltage like it is now.

The wires I used to wire my relay were brown/pink (+) and black/red (-). Which are the correct wires. Once I do the rest as I stated above everything should work great :thumbsup:

you will still need to get the controller from aeromotive if you plan on street driving the car.. if not, you will burn the pump out prematurely.. driving it in traffic and slow cruise speeds will cause the pump to get hot and over heat/burn up the pump.. the controller will solve this issue!

 

[Black306]

Are you trying to wire around/bypass the FPDM or are you trying to use the FPDM is activate the relay?

If you are trying to use the FPDM to activate a relay, then you have the right idea (using the BN/PK and RD/BK wires). That'll run the pump like in a stock configuration where the pumps will prime for a couple seconds when key on/engine off but then run the pumps all the time when running. As you said, you'll need the tuner to make sure the FPDM puts out a constant ~12v when the engine is running.

If you are trying to bypass/remove the FPDM, that is a matter of using the DG/YE wire on pin 85 (or 86) on the relay and then ground pin 86 (or 85). The down side is that the pumps will run when the key is in the on position irregardless if the engine is running or not.

 

[meats50]

I wired using the BN/PK and RD/BK wires as you described. And the fpdm is adjusting voltage. I do want to power the relay in the way I have it now, where the pump primes, shuts off, then runs constant 12 v once ignition is on. I planned on having the tuner change the value in the computer to where the computer sees a return style system and doesnt try to adjust the voltage to the pump. then disconnect the fpdm plug and wire the incoming power to the bn/pk wire and corresponding ground to the rd/bk.I hope What im trying to describe makes sense. Because thats what im asking is will this work? or does it have to be one of the 2 options you described- ie leaving the fpdm hooked up or constant power key on.

 

[Black306]

I wired using the BN/PK and RD/BK wires as you described. And the fpdm is adjusting voltage. I do want to power the relay in the way I have it now, where the pump primes, shuts off, then runs constant 12 v once ignition is on. I planned on having the tuner change the value in the computer to where the computer sees a return style system and doesnt try to adjust the voltage to the pump. then disconnect the fpdm plug and wire the incoming power to the bn/pk wire and corresponding ground to the rd/bk.I hope What im trying to describe makes sense. Because thats what im asking is will this work? or does it have to be one of the 2 options you described- ie leaving the fpdm hooked up or constant power key on.

What I understand is that you want to have the FPDM initially hooked up, the car tuned so that the ecu knows there is a return style fuel system, then remove the FPDM. If that's correct, it won't work. Your options are as I described them above.

Power to the FPDM, going in through the DG/YE wire, is constant as long as the key is in the on position regardless if the engine is running. It is the job of the FPDM to regulate voltage to the pumps based on the input provided by the ecu, which goes into the FPDM on the WH/RD wire. That input signal cannot be used to control a relay. It needs to be interpreted by the FPDM.

 

[meats50]

thanks for he heads up. saved me alot of headache unpinning the plug and soldering wires only to find out it wont work. Ill use the dg/ye wire you suggested. thanks for all the info.