My m8 has changed the fuel pump on his 4x4 cos as the old one was starting to get noisy the new pump wouldn't work so he called me round to check it out.
I found no power at the cut out switch and again non at the multi plug in the back panel.
I then linked across the the fuel pump relay and got 12v at the back
how does the fuel pump relay switch im sure it is ecu controlled?
I found no power on the switched side of the relay (blue green/blue black wires)

any one seen this before and got an idea what it might be?
I'm going on holiday on wednesday and need to help him get it going before I go or his nat day trip is up in smoke!!
steve

 

Can't believe that in 10 hours only 4 people actually read this!!

I constantly help out with advice on here, now it's my turn for help I get none!!

must change my deodorant!!!!


steve

 

think the relay is switched via the ecu ...

trying to find my wireing diagram now has he cheked the fuses ???


http://www.ford-cosworth.dk/manualer/cos_w_diag.jpg

a 3 door one but the idea is the same

pin 28 switches from ecu .. pin 30 on relay is power in .. pin 87 switched power out .. looks like there is a fuse on the supply in aswell

not much help i know .. but your deoderant smells better today

 

cheers m8,
he checked the fuses and said there ok another strange thing that might be related is the electric windows have stopped working my thought is that the ecu is not getting powered up.

steve

 

Did he remove any connections from the battery before changing the fuel pump?

 

electric windows are not on ecu side .. so i would be looking back towards the battery or fusebox's ... sounds like summit has gone pop

http://www.cannell.co.uk/Ford_Worksh...20Diagrams.pdf

larger sized one ...

 

He did remove both the + and - cables fro the battery before he started.
must admit tho that when I looked at the main power cables onto the battery (all the smaller thickeness ones in red sleeving) they do look a bit ropey as some of them have tight turns in them which may have snapped internally.
Am I right in thinking that all these power different systems Ie ABS,lights, ecu, windows etc??
so if I remove them check for breakeages I might be on the right track?

steve

 

Sounds like you know what you are doing Steve

 

Daft thing is I am a part time commercial auto elecrician!!!
but this one has stretching my knowledge as in 6 years of owning an identical car the fuel pump switching cuircuit is only thing I never had to work on!!

steve

 

Is the ecu getting power aswell?

 

Steve

Did you check that the relay came live when cranking the key ?

 

ere no

surely that relay goes live with the ignition to build the pressure up in the system it then switches off on overload as the system pressure is built up. or am i talkin bollox? lol

basicly it won't do the above!!

steve

 

any one know the pin number to check that out

the amal valve does click so that does seem to suggest the ecu is getting powered up tho

steve

 

It sounds like there is a + wire missing off the battery?????

Fast way to check if the ignition live circuit is working take the 5 pin fuel pump relay out and replace it with a yellow 4 pin relay turn the ignition on so you have the lights on the dash if the fuel pump runs up and it will stay running to as this bypasses the ecu control of the pump then there is nothing wrong with the power supply to the relay.

Obviously if the pump dont run then the problem lies in the ignition power supply to the pump as i can see you already have the perm power there as bridging the wires you can get the pump to run

 

cheers mark, I was bridging the yellow 4 pin relay to power the pump, is the green 5 pin relay the one that has the timer on?
if so whats the yellow one that I am bridging for??

steve

 

you got a pm m8

 

I am not the best at electrics by far Steve

But try it - I`m not with the car now to check but am sure the pumps dont come to life until its cranked

 

when he disconnected the battery

make sure that he didnt disturb the connections at the back of the battery as these are for your managament fuel pump, ecu etc

they can work themselves loose over time and always cause problems

just something easy to check first

fuel pump relay is yellow 4 pin main wire to pump is black with red trace

 

fuel pump relay fuse behind glovebox

 

steve, give me a call if you get stuck.

Cheers

Ryan

07919537128

 

quick update, last night we had power at the coil, we then lost all the dash warning lights (ignition, oil etc) heater fan works ok I then tried the indicators and hazards with no joy, i cleaned the ignition relay contacts and the dash lights worked again then tried them a second time and they failed again.
i'm pretty sure the fault is a ignition + supply issue but I don't know exactly what some curcuits work some don't , I tried continuity tests on the battery wires and they seemed ok.

god knows whats wrong but I have had to leave my m8 to call a sparky as im about to fly to spain on my hols, I do know of an internet pub so will check back later!!

steve