rabmc

As above just fitted my new pump and filter there tot he cossie 044 bosch pump , redone connections etc , and i took the voltage at pump accross terminals with car running and got 8.98volts , is this ok ? thought it should maybe be 12ish anyway my last cossie pump was rewired from battery i think and through big fuse , and my 3 door just has old wires down there st pump , i know people rewire there pumps , where do wires run from??? and whats the main reason , thanks

Just out of intrest dont want anyhting going wrong when the boost gets upped and getting set up

cossie2be

Relayed with a fused wire from battery with good decent cable, using existing cable to switch relay

IANS2RST

iTrader: (1)

definately rewre it ,
use the original fuel pump feed as a trigger wire for a separate relay with suitable cabling & fuse straight from the battery.
fuel pump voltage should be the same as battery/alternator voltage ie around 14.2 volts when running.

PGT

tried the same test on mine a while ago and got 10 volts at the pump whilst car idling. then wired a 100 watt headlight bulb across the pump to simulate the additional current draw when on boost and got 8.5 . traced the voltage drops acoss the various components and found that the big fuse next to the pump relay was too hot to touch which was mostly due to old and poorly fitting crimp connectors. the relay had pitted contacts as well. after new connectors and relay the fuel pump voltage is now about 1.5 volts less than battery voltage.

Eagle

iTrader: (2)

the reason....


run a nice fat piece of cable from the positive from the battery with a fuse next to the battery down to the fuel pump.
then do the same with the negative....
use the old wireing to trigger a relay that switches the new positive feed to the pump.
mine is sat in the boot next to the fuel pump trip.

rabmc

Cool eagle totally undrstand that ! will do thought that voltage was a bit suspect would it be best to run it through car etc or down underneath ? what way does existing run

Eagle

iTrader: (2)

i went to halfrauds and got some 2 guage totally overkill i know but thought why not, dont really want to take the chance.
ran mine down under the side of the car alongside the fuel lines, but made sure it was well covered with a rubber pipe just incase like
up through a grommet into the boot where it is now switched via a nice monster relay then back down to the pump.
took about 3 hours all in and works well i get no voltage drop atall even with all the electrics going lights heated screens rad fans etc etc etc

Stu @ M Developments

iTrader: (12)

Rewire it.
The current draw at 5.5bar line pressure (I.E: On Boost) Is very high and ive seen them drop immensely at this level. Bear in mind, on boost the whole electrical system gets grief so even your supply will be down, before even takling into account your crappy old wiring!!

Graceland

There is a thread in the Tech section with a how-to guild that I wrote some time ago on how any why you need do it

Eagle

iTrader: (2)

https://passionford.com/forum/viewtopic.php?t=174562

rabmc

Thankx

Eagle

iTrader: (2)

just out of curiosity what is the current draw at full boost on a 044 pump ??

Fiecos Dan

The flows are rated @ 13.5volts @ full load, usually 5-6 bar on a cossie.

i used 25 amp wiring, and fitted 2 earths as well.


@ 72 psi load, i see 13.8 @ battery, and 13.4 @ pump terminals.

Fiecos Dan

18 amps @ lockout (11.2 bar, 162psi)
13 amps @ 5 bar, 73 psi.

rapidcossie

rab...maybe this prob has someting to do with the bat light etc being on at nite?

Fiecos Dan

Also before i rewired it,


i had
at battery = 14.0 volts, @ pump at 74psi = 11.8 volts = 3.8 ltr/min

Then with all electrics on, (lights, heater, engine fan,steario etc etc)
at battery = 13.4 volts, @ pump at 74psi = 11.0 volts = 3.5 ltr/min


With new Relay, relay feed and pump wiring,

No electrics on, at Batt=13.9, pump @ 74psi = 13.5 and 4.7 ltr/min
all electrics on, at Batt = 13.6, at pump @ 74psi = 13.2 volts and 4.45 ltr/min

Ryan

if doing it just use good quality cable, dont use dirty great 1 gauge sterio wire.

Some people completely overrate the fuel pump wiring, not that it has an adverse affect.

Also it may be worth checking round the engine loom if it isnt new, often overlooked and often the cause of meltdowns.

Also look over charging circuit and battery health

Rod-Tarry

To make sure of max voltage to the pump , I use a 16v addjustable supply
so I can adjust the volts at the Pump, I adjust to 14.8v & this will be constant whatever the load. If the Alternator fails it will still supply this voltage until Battery volts drop below 9.6V. Would be my first mod on a Cossie but few spend the money on this engine saving device.
Rod

Fiecos Dan

How much Rod?

RobCarden

hi rod - have you got a name or a link for this part? thanks - rob

Eagle

iTrader: (2)

i also made sure i had a second charging feed from the alternator

costina

iTrader: (1)

I've done this recently on my saff and have gained 1.2 volts at the ECU according to the secs monitor

Which then gives u a better voltage for lambda sensor as its on that curcuit

Ryan, PM me a price for a loom,lambda controlled,MSD coilpack.L8 Ta

rabmc

Hmmm my battery light comes on faintly at night people , my alternator is new and brand new battery , some times when out especially at night my car lights etc interior and headlight goes dull all of a sudden like a surge or something , maybe my low voltage at pumps related as euan said earlier

Fiecos Dan

Renew the connectors/wiring of the alternator, this is a common cause with poor charging.

vroooom ptssssh

Would this be worth while doing on an Escort turbo? specially 21yr old s1 wiring? what voltage should I see at the pump at idle?

Fiecos Dan

Oh yes. You want to be seeing 13.8-14.2 @ battery, with and with out all electrics on.

And 13.3-13.6 @ the pump @ full pressure, but also just as important to check the fuel flow as well.

vroooom ptssssh

cheers Dan, how would I check it at full pressure? just get someone to sit with a voltmeter connected and take it out for a spin?

Fiecos Dan

i personally, Have tha car runnig @ 1500 rpm (charging fully)
and i then fit a 2nd fuel reg, and gauge then adjust the pressure after the pump to set PSI, and then take the voltages, and measure the fuel flow from the tank return.

vroooom ptssssh

Cheers, I think it'll be a job for someone else that knows what theyre doin jus gettin the car ready to use on the road and want to improve on things like this.