Ok I need some help, my car is hesitating up top wont make full boost and detonating, I pulled my trouble codes and got:0232 - Fuel Pump Secondary Circuit High,P0231 - Fuel Pump Secondary Circuit Low, Now my car is set up using a full return system with a Barry Grant pump, Does my car even need a FPDM? if you look at the pic I have my pump wired to the brown and pink wire off the FPDM to come on when keyed, thats running to a aftermarket relay, the pump changes speed so is my pump running off the FPDM being tapped off those wires and causing me trouble??This is just a diagram i foung when upgrading the wires to the fpdm so the relay inbetween the inertia switch is not where mine actually is, I just tapped the pink/brown wire to power my relay that runs my pump

#ad

 

I don't think so.
If you have Stand Alone Return Style Fuel System ,you will not be able to pull codes out of the PCM on the fuel pump.
The chip or the tune in you pcm shoud have stock fuel system turn off.
The pick & brown wire is just sending a signal to turn on the relay when the key is on.

 

you dont not need the fpdm, my car runs with it unpluged. The purpose of the fpdm is to vary the voltage to the pump, you do NOT want this on a return setup. This is how I wired mine

I found the keyed 12v to the fpdm - this wire was the signal for the relay (unplug the fpdm to find it or get a wiring diagram) I cut this wire and extended to my new realy, so now the fpdm does not get power.

Then you have a direct 12v from battery, ground and output on the other terminals of the relay.

The pump voltage on your setup should stay constant!!!

 

to make this clearer here is the actual wiring. FROM RELAY red-12v battery,Gray-Ground-Purple-PumpYellow is tapping into the brown/pink wire I cut from the stock harness its not plugged in because I have a fuel cell and everything else is aftermaket, So is the wire that I tapped running out of the fpdm and messing with my pump?? and setting codes??

#ad

 

Also I very much appreciate the feedback no one else seemed to be able to help me out...So i should not be getting circuit codes because they should be turned off in my tune??

 

ok thats the connector at the pump on the underside of the car right? That is not the right wire if so. Your fpdm is still varying the voltage there! Now that I think about it, im pretty sure you want the pink/black wire.

Heres what to do, unplug the fpdm turn the key on. you should have 12v at the pink with black. If so, reroute the yellow wire to the pink/black. I cut the pink/black so the fpdm will NOT turn on and connected the powerside of the pink/black to my relay.

 

Yes that is the stock connecter that went to the pump, it worked fine its been that way for a while but then i noticed my pump would slow down and speed up while idleing parked, So unplug the fpdm and run off the pink/black wire instead? Also is this whats tripping my trouble codes and making me run bad, I never noticed the codes then checked when it was running ruff trying to boost it, my car is still a work in progress

 

Correct! The codes are probable related to how you have your pump wired.

 

Thanks I appreciate the help, im gonna give it a try and ill post back up if it fixes my probs...

 

well fixed my codes but my car still wont make boost itll go to 5lbs then break up bad, i checked all my injectors,coils,and plugs all working....im stumped

 

need more info here!! what plugs and gap?? what fuel pressure?? did this problem just start occuring? did you change anything to possible cause any issue?? is it tuned properly??

 

Ive been working on setting up a tune I only have the boost set at 10lbs my motor only has about 100miles on it, im using ngk plugs and gapped them all around 28-30 It was making boost and pulling good making test runs then it back fired and all went down hill breaks up by 5lbs of boost, My airfuel was around 11.5 and im working with a good tuner that know his stuff so i dont think its really the tune, I did have an injector that was failed for a while but i dont think it would cause engine damage...

 

do u have a wideband?? sound like a lack of fuel to me

 

I know that this will not solve the problem you are having. I like to leave the returnless portion of the tune working so that the computer can correct for low pressure (clogged filter, ect). There are a few things that need to be changed in the tune to be able to do this though. If you want to do this let me know.