fuel pump wiring mod

[barry798]

is the a diagram for doing the wiring mod to the fuel pump to make sure it gets the right voltage
thanks

[m1tch]

Is this for an FD or FC?

[SiH]

FD? The easy way to do it is to run a relay from the feed to the pump in the boot

There are some other more complex ways that involve removing the resistor system completely. It depends how far you want to go

[barry798]

ya for a fd ,so remove wire to the pump (have a external 044) then connnet this to the realy
whot amp relay and dont suppose you have the numbers for whot wire to which terminal on relay
many thanks

[jon103a]

hi, a standard 30 amp 4 pin relay will be
85 switch feed in (wire that ran old fuel pump)
86 to earth(body/good metal contact)
87 fused feed from a good ignition or battery feed
30 output to feed new pump
a 5 pin relay will have 87a in the middle, just ignore that one.
i seem to remember that pip told me the o.e fuel pump uses variable voltage to regulate the fuel supply, in which case a voltage drop below 9volt could cause the relay to drop out completley. jon.

[barry798]

would this mod be ok using a 044 pump + whot amp fuse sould i use from the battery

[jon103a]

i would use a 15 amp fuse from the battery, its a bit bigger than the running amps for the pump but will allow for initial start up power surge the pump, it should only run at 6-8 amps and wont blow the fuse unless there is a real problem. with the original pump running on a variable voltage (resistor) system when i do mine i also intend to try it running the switch feed(the wire that ran the old pump on terminal 85) directly from the ignition so it gives a stable voltage to the relay as i have fitted an uprated adjustable mechanical fuel regulator under the bonnet. jon