I looked again at the diagram, and indeed what is happening is that once your rewire gets activated, it can be self perpetuating. Power from your rewire is running backwards up the low voltage wiring, up through the fuel pump resistor, and back around through the low voltage relay which is an N/C relay. I knew there was something about that rewire that bothered me. Nevermind that it took me three months to figure it out.

 

So its not particularly easy for that easy rewire relay to be held active after shutting off the motor. If the car is idling when the key is turned off, then relay #3 is in the open position, and there is no power going to the rewire. When the motor is turned off, relay #3 will close, but at the same time, relay #1 and #2 will open, so there should be no way for power to reach the easy rewire relay. However, there must be some small amount of residual energy storage in the circuit or the timing in the change in status of relays is sometimes sufficient to activate the easy rewire relay as the motor is turned off. Once that happens, the easy rewire is self perpetuating when the motor is off because relay #3 is N/C.

 

I see what you mean, I suppose either a diode or another ignition activated relay would cure the problem. Adding another relay would again start complicating the wiring tho.

 

Edit

 

So if I run my car for more then a few minutes it doesn't stay on... But if I start it and shut it back off it will stay on... Kinda goes with what Fred said... Good new for me since it doesn't stay on during normal use

 

That problem happens to me sometimes, i simply turn the key back to ign and then back off to solve it. Im thinking of getting some solid state relay's to replace these generic ones.

 

It looks as though you need to isolate that circuit with another relay..... That way you make sure there isn't any stray voltage getting introduced.
I ended up using a 100 amp fused distribution block with 12 outputs for my pumps relays and guages. Before the block I used a 100 amp breaker and also a relay so everything would work in association with the ignition. I haven't finished it all yet but that will shut off voltage to the pumps even if the relays are being backfed enough to keep the relay active.


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The alternate method doesnt truly work... I removed my pump resistor and it started and runs fine without it... It should have switched to low voltage and shut down but the hardwire over ran it...

Or am i missing something that makes that happen

 

Not sure why yours does that but I remember checking mine when I was done and I was getting 9v at the pump at idle and 14v once a higher load was hit.

 

Are you still running your easy rewire setup? If so, did you ever add a diode to prevent the fuel pump relay-stuck-on after driving problem; and if so, where in the wiring is the diode installed?

 

Yes I am still running it, I looked into it a bit but it seems most common diodes are for low amperage which wouldn't work with the circuit, the only other thing I could thing of would be to try a solid state relay in place of the standard automotive one but they are also wired differently which would complicate the wiring.

Basically I figured out that the problem only occurs if you turn the car off and back on quickly, IE sometimes it would happen when flashing the ecu. But as long as you take 2 seconds between key off to key on it doesn't seem to happen.
And even if it does just start the car up and let it run for a minute and i will fix itself.

 

Yea i guess itwas the back feed fred talked about or my relay is iffy... It shut down today... Guess i should have tested more...

 

Hi

I would like to know if either simple or the complex method of wiring is still functioning. My question is I'm still figuring if I should run the a large single pump with this wiring or run another controller like a aeromotive fuel controller (disable the factory controller). Or make it less complex run a Blaq op/buschur twin pump with there fuel switch/controller and be done with it.

Any suggestions will help.

 

I'll share what i did. I have a dp setup, I did the rewire kit. I have 12 vdc to the pumps with a relay. When the ecu triggers the pumps to turn on it grounds the the relay which in turn allows power to the pumps. Works just like factory

 

Im relocating acd pump to the trunk so my plan is to pull the entire relay bracket from the engine bay and source ACD and fuel pump DC+ from a fuse block in the trunk.

Here is a crappy mspaint I came up with. thoughts? Basically just feeding the stock relay and the stock resistor with voltage straight from the battery, but leaving the ecu control. Would the pump still get the higher voltage like this?

edit: DOH! Im an idiot. I'll still need an additional relay to kill the power from the battery. Just tie it into the same source as the stock relay #3. (revised schematic)