Fuel pump rewiring

[Belle427]

Has anyone rewired the pump and if so where did you run the cables?
I cant see a route down the existing door sill area unless it goes under the carpet which i want to try and avoid.
On top of the tranny tunnel is an option.

[Penelope Stopit]

Where is the battery situated?

[Belle427]

Still in the original position in the footwell.

[SwanJack]

The original route is through the sill isn't it? I went under the carpet as a ''temporary'' measure!

[Belle427]

Somebody mentioned it may be full of expanding foam.

[Penelope Stopit]

If the battery was behind the seat or in the boot I was going to suggest you may like the idea of fitting the fuel pump relay in the boot, bridge out the original fuel pump cable at the fusebox and use that same cable to switch the newly fitted relay in the boot

If you are running a cable to the rear you could still do the above modification by running a battery positive to the boot area

Thinking about this.....I am guessing that you are rewiring the pump for reliability, you will only get the reliability you seek by modifying the fuel pump circuit so that it doesn't use the original TVR (VW) fusebox................If rewiring the fuel pump circuit it is best to fit the fuel pump relay in the boot, there will never be volt-drop problems from front to back after this modification

I hope I've explained this ok

[Belle427]

Penelope Stopit said:

If the battery was behind the seat or in the boot I was going to suggest you may like the idea of fitting the fuel pump relay in the boot, bridge out the original fuel pump cable at the fusebox and use that same cable to switch the newly fitted relay in the boot

If you are running a cable to the rear you could still do the above modification by running a battery positive to the boot area

Thinking about this.....I am guessing that you are rewiring the pump for reliability, you will only get the reliability you seek by modifying the fuel pump circuit so that it doesn't use the original TVR (VW) fusebox................If rewiring the fuel pump circuit it is best to fit the fuel pump relay in the boot, there will never be volt-drop problems from front to back after this modification

I hope I've explained this ok

Im going megasquirt so most of the wiring will not be using the Tvr fusebox.

[Penelope Stopit]

Belle427 said:

Penelope Stopit said:

If the battery was behind the seat or in the boot I was going to suggest you may like the idea of fitting the fuel pump relay in the boot, bridge out the original fuel pump cable at the fusebox and use that same cable to switch the newly fitted relay in the boot

If you are running a cable to the rear you could still do the above modification by running a battery positive to the boot area

Thinking about this.....I am guessing that you are rewiring the pump for reliability, you will only get the reliability you seek by modifying the fuel pump circuit so that it doesn't use the original TVR (VW) fusebox................If rewiring the fuel pump circuit it is best to fit the fuel pump relay in the boot, there will never be volt-drop problems from front to back after this modification

I hope I've explained this ok

Im going megasquirt so most of the wiring will not be using the Tvr fusebox.

I now remember you mentioning Megasquirt in another topic, you didn't have all the information at that time of posting
I'm guessing that you're running an uprated fuel pump cable from a Megasquirt supplied relay to the rear for the fuel pump and that cable has no breaks/connections in it from front to back

Ooops if this is the case .......Ignore me and I'll gladly go away

Enjoy the wiring job

[Sardonicus]

Go transmission tunnel top its uncluttered and can cable drop nicely to the pump , also real easy to run new wiring from pass foot-well to rear of car this way

[Belle427]

Penelope Stopit said:

Belle427 said:

Penelope Stopit said:

If the battery was behind the seat or in the boot I was going to suggest you may like the idea of fitting the fuel pump relay in the boot, bridge out the original fuel pump cable at the fusebox and use that same cable to switch the newly fitted relay in the boot

If you are running a cable to the rear you could still do the above modification by running a battery positive to the boot area

Thinking about this.....I am guessing that you are rewiring the pump for reliability, you will only get the reliability you seek by modifying the fuel pump circuit so that it doesn't use the original TVR (VW) fusebox................If rewiring the fuel pump circuit it is best to fit the fuel pump relay in the boot, there will never be volt-drop problems from front to back after this modification

I hope I've explained this ok

Im going megasquirt so most of the wiring will not be using the Tvr fusebox.

I now remember you mentioning Megasquirt in another topic, you didn't have all the information at that time of posting
I'm guessing that you're running an uprated fuel pump cable from a Megasquirt supplied relay to the rear for the fuel pump and that cable has no breaks/connections in it from front to back

Ooops if this is the case .......Ignore me and I'll gladly go away

Enjoy the wiring job

Yes thats correct, from new relay to pump with no joints.

[Belle427]

[quote=Sardonicus]Go transmission tunnel top its uncluttered and can cable drop nicely to the pump , also real easy to run new wiring from pass foot-well to rear of car this way [/quote

Certainly the easiest route.

[Belle427]

Just to close this out and help anyone thats thinking of doing the same.
I ran a pair of 2.5mm cables through some small flexible conduit, over the transmission tunnel and drilled a hole in the corner of the passenger side compartment behind the seat.
This exits nicely just above the fuel pump.
With radio out its fairly easy to route the cables, i plan on earthing direct to battery and connecting the power straight to the inertia switch.(as per the old cable)
This eliminates the multiple joints in the circuit.

[Sardonicus]

The stock pump run at a non standard 3 BAR draws 11 amps out of interest I would imagine around 8-9A at 2.5 BAR and with clean multi connectors and good terminations but stock wiring I still had a big drop on the stock wiring circuit this was tested a long time back whilst playing around