RXtacy's slooow build up

[RXtacy]

Originally Posted by TitaniumTT

Must label. Saves looking things up two or three times. I saw the blue tape. I either use that or a different color zip tie.

Exaclty.

Don't forget there's going to be a bunch of wires, power and or grnd that are going to be spliced together. Like one grnd goes out to 5 different connectors.

Yes, fortunately the branches are easy to identify as they used but crimps and wrapped them in blue tape. For the few circuits I've removed so far I've just gone one circuit at a time and cut it at the crimp. If that whole branch ends up getting removed so be it, but I'd rather not mistakenly remove an entire branch that needed to stay.

Mike, I had a thought this morning..... how is the fuel pump wired exactly. If memory serves, it's going to take a signal from the ECU, run through the firewall side, up to the relay box, back through the resistor, back into the front harness and then connect to the rear harness and go off to the fuel pump. That wire that once powered the fuel pump, trace that back to the jump between the front are rear harness and take the front harness section of wire and run it over towards the ECU.

That can be the new trigger for the relays that will be in the trunk area.

Ign switch sends power through the FP relay coil and to the ECU (which I assume latches to ground). Ign switch also sends power through the circuit opening relay, then through the FP relay contacts and FP resistor in parallel. From there it goes to the FP. See diagram below.



So if I'm understanding correctly you are suggesting removing the W/R wire from connector B1-04 (connector on the relay block) and sending it over to the ECU? I have already eliminated the FP resistor circuit in the diagram. It would appear I could also eliminate the L/R wire coming off the circuit opening relay through B1-03?

*Note X-10 is the connector between front and rear harness.

[TitaniumTT]

Originally Posted by RXtacy

Yes, fortunately the branches are easy to identify as they used but crimps and wrapped them in blue tape. For the few circuits I've removed so far I've just gone one circuit at a time and cut it at the crimp. If that whole branch ends up getting removed so be it, but I'd rather not mistakenly remove an entire branch that needed to stay.

Exactly

Originally Posted by RXtacy

Ign switch sends power through the FP relay coil and to the ECU (which I assume latches to ground).

You assume correctly. It's incredibly rare for an ECU output to NOT latch to grnd. Can be confirmed in the diagram by following the ign switch back to positive.

Originally Posted by RXtacy

Ign switch also sends power through the circuit opening relay, then through the FP relay contacts and FP resistor in parallel. From there it goes to the FP. See diagram below.

Be careful with the circuit opening relay. I would be surprised if it didn't power more than the FP relay and resistor.

Originally Posted by RXtacy

So if I'm understanding correctly you are suggesting removing the W/R wire from connector B1-04 (connector on the relay block) and sending it over to the ECU? I have already eliminated the FP resistor circuit in the diagram. It would appear I could also eliminate the L/R wire coming off the circuit opening relay through B1-03?

*Note X-10 is the connector between front and rear harness.

Yes, take the W/R from X-10 and move it to the ECU. In stock form the would've been positive, now it will be the relay trigger signal. When you go dual pump we can get overly fancy like I did and modify two aircraft safety switch's and a pair of SPDT toggle switch's to control the pumps independantly.

I would start at the relay block and work backwards regarding the L/R. It might be used for more than just the FP. If it's not, than what we can do is, because of the physical location of the Circuit opening relay, we can plan to use that for the lift pump, because that will be a stock pump with zero pressure and little draw, use the circuit opening relay and factory fuse in that module for the lift pump.

In that case I would use the B/LG wire that jumps between the EGI and the Circuit opening and cut the jump, find something similar in your tefzel stock and run that over to the ECU. Use the L/R as the power for the lift pump, and split the B/LG before the module to go to the dual SPDT switchs.

*Note - the switch's aren't necessary at all, although I've found them very useful. The way to wire them is the common terminal (middle) goes to the gnd side of the coil for the relay. The position that would be closed when the safety cover is closed hooks to the ECU. The other terminal (cover up, switch up) connects to gnd. **Note - this is an on (mom)-off-on switch** So you can close the cover and the ECU controls it. Flip the cover up and center the switch breaking contact. This allows pressure to be bleed off. Of flip the switch up to the mom position and prime the system. It allows you to fill the surge tank manually to avoid damage to the main pressure pump.

Logical? Sensical?

[RXtacy]

Originally Posted by TitaniumTT

You assume correctly. It's incredibly rare for an ECU output to NOT latch to grnd. Can be confirmed in the diagram by following the ign switch back to positive.

Figured.

Be careful with the circuit opening relay. I would be surprised if it didn't power more than the FP relay and resistor.

I'll trace the wire.

Yes, take the W/R from X-10 and move it to the ECU. In stock form the would've been positive, now it will be the relay trigger signal. When you go dual pump we can get overly fancy like I did and modify two aircraft safety switch's and a pair of SPDT toggle switch's to control the pumps independantly.

I would start at the relay block and work backwards regarding the L/R. It might be used for more than just the FP. If it's not, than what we can do is, because of the physical location of the Circuit opening relay, we can plan to use that for the lift pump, because that will be a stock pump with zero pressure and little draw, use the circuit opening relay and factory fuse in that module for the lift pump.

In that case I would use the B/LG wire that jumps between the EGI and the Circuit opening and cut the jump, find something similar in your tefzel stock and run that over to the ECU. Use the L/R as the power for the lift pump, and split the B/LG before the module to go to the dual SPDT switchs.

*Note - the switch's aren't necessary at all, although I've found them very useful. The way to wire them is the common terminal (middle) goes to the gnd side of the coil for the relay. The position that would be closed when the safety cover is closed hooks to the ECU. The other terminal (cover up, switch up) connects to gnd. **Note - this is an on (mom)-off-on switch** So you can close the cover and the ECU controls it. Flip the cover up and center the switch breaking contact. This allows pressure to be bleed off. Of flip the switch up to the mom position and prime the system. It allows you to fill the surge tank manually to avoid damage to the main pressure pump.

Logical? Sensical?

Mostly. Not 100% following the SPDT switches, but I get the gist of what your saying.