Mazda Rotary Club

General => General Technical => Topic started by: barry798 on September 30, 2009, 09:03:20 PM

Title: fuel pump wiring mod
Post by: barry798 on September 30, 2009, 09:03:20 PM
is the a diagram for doing the wiring mod to the fuel pump to make sure it gets the right voltage
thanks
Title: fuel pump wiring mod
Post by: m1tch on October 01, 2009, 09:50:45 AM
Is this for an FD or FC?
Title: fuel pump wiring mod
Post by: SiH on October 01, 2009, 12:33:54 PM
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 :)
Title: fuel pump wiring mod
Post by: barry798 on October 01, 2009, 07:03:41 PM
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
Title: fuel pump wiring mod
Post by: jon103a on October 01, 2009, 08:19:03 PM
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.
Title: fuel pump wiring mod
Post by: barry798 on October 02, 2009, 01:32:42 PM
would this mod be ok using a 044 pump + whot amp fuse sould i use from the battery
Title: fuel pump wiring mod
Post by: jon103a on October 02, 2009, 03:58:25 PM
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