Hi anybody any ideas

Clasic 1994 wrx import

On a track day at Olton Park yesterday just exiting shell oils corner
when I had a total loss of power and car just stopped session was red flagged and I was recovered to the pits, unable to locate problem so had to get recovery to home after checking things out today I have found that their
Is no power getting to the fuel pump?
Tried to obvious no fuses blown and everything else seems to be getting power
Somebody suggested the car might have a fuel pump cut off inertia switch
But nobody has been able to confirm this.
Any help would be greatly appreciated

Many thanks

Tony.

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Hi Guys

PROBLEM SORTED.

Id likes to thank all the people who posted advice or help
But very special thanks go to DUNK, TICKY & NORMSKI
Who all provided access to wiring diagrams which provided
The information to locate the problem

As reported earlier in the post the problem was no power getting
To the fuel pump, the first and most obvious thing was checked
Which was all the fuses, but no fuses or relays in either of the
Fuse boxes were marked as being for the fuel pump and all appeared
To be intact but this turned out not to be the case.

After following the circuit back from the fuel pump though the
Fuel pump relay to the power supply routing table MB-2 SBF-2.

SBF-2 turned out to be a 30amp fuse in the under bonnet fuse
Box, this fuse doesn’t look like an ordinary fuse. it looks more
Like a miniature relay there are two in total side by side green
And have a clear plastic top.
On looking very closely though the clear plastic top I could just
See a ½ mm gap in the fuse link.

You can imagine the words that came out of my mouth at this time
after paying For a recovery truck from oulton park to Oldham
and spending Hours trying to find this fault.

WE LIVE AND LEARN

Hope this information might help somebody else out in the future.

Again many thanks to you all.

Tony.

 

Dude! Sounds really heavy . . .

Good luck with it though!

 

Check the connector under the rear seat, is a common problem!

 

Hi moley

Already tried that, traced the feed wire back too
under the dash drivers side, still no power

Thanks

Tony

 

if im not wrong most cars have a relay controling the fuel pump cind that and make sure it aint loose or died

 

Hi zoney

Yes that’s what I expected but I have checked both fuse boxes
And none of the relays seem to be for the fuel pump if anybody
Knows where the fuel pump control relay is it would be greatly
Appreciated if you could let me know.

Thanks

Tony

 

The fuel pump relay is above the interior fuse box behind the dash.Theres 3 relays up there and from memory the silver one is for the fuel pump.Probably easiest to remove the whole panel from below the steering wheel

 

Hi turbotits

Found the three relays you mentioned thanks but the feed wire from the pump seems to go to the brown relay does this sound right?
relays seem to clicking away ok with the ignition but still no power to
the fuel pump the plot thickens.

Thanks

Tony

 

Could well be the brown relay,My memories not what it was.It may be clicking but doesnt mean its sending any power down the wire. Check it has all the right feeds 1 perm live one switched live or earth If its switched live it should have 1 earth and the output wire

 

yep mine done the same thing some time ago now and that was the fuel pump relay

 

You can ofcourse bypass it as a temp measure.Switched live wire connect to output wire Preferabley with a fuse inbetween for safety.I didnt tell you that.lol Use an 8inc peice of wire,cut in half crimp a male spade to one end of wire and female to other end do this twice.Plug the male end into the relivant holes on the relay holder.You now should have to female spade ends hanging from the relay holder.Stick a 10amp spade fuse into the female ends. One homemade fuseable link.

 

quick way to confirm..


12v car battery, two wires.. connect straight to fuel pump, if it runs, thats out of the equation.

forgive me if i,m teaching you to suck eggs...

sequence for starting...

1) ignition on.
2) ecu energises fuel pump
3) ecu looks for signal from the following
4) cam sensor
5) crank sensor

if signals recieved, and valid ecu will initiate starting providing spark to plugs, power to fuel pump etc.

you may have a duff cam or crank sensor,,


as i said eliminate the fuel pump and then work back


mart

 

1 vote for fuel pump relay - when ignition gets turned on pump gets a 12v jag then relay cuts power to 5-6v , it was the 5-6v that blew on my relay.

as suggested try 12v straight to pump in boot

 

i know they suffer from a bad earth at pump
no inertia switch fitted
also check your alarm system if its an after market could have a bad/broken connection

 

Hi mart360

Many thanks for your input you seemed clued up so could I just run something by you
Definitely ruled out faulty fuel pump done a 12v bypass pump spins up just fine so moving onto crank sensor, and cam sensor the crank & cam sensors I believe confirms to the ecu that the crank & cam are rotating once the engine is running.
But when you are turning the ignition key on third position just before the engine turns over the ecu switches power to the pump and you here the pump spin up for a second or
So till it pressurizes the fuel lines but this doesn’t happen so I would expect the ecu to ignore these sensors at this stage of startup thus eliminating them from the equation as at no time does any power reach the fuel pump I have had a digital volt meter connected to the feed wires to the fuel pump and constantly watched them while turning the ignition though it’s sequence. And at no time have I seen any voltage reach the fuel pump I am beginning to suspect the fuel pump relay or the ecu by now. What do you think?
Again any input is greatly appreciated.

Many thanks to all who have responded

Tony

 

Hi Rexabusa

I am very interested in your reply could you please elaborate on what you mean by 12v jag and the part about the 5 to 6v

Many Thanks

Tony.

 

i had a multi meter and chopped the wires under seat , got my mate to turn ignition on - multi meter showed 12volts then relay clicked and multi meter showed zero. changed relay (green i think) then tried again and 12volts - relay clicked then 5.?volts showed on relay.
i think ecu must control relay to vary fuel supply when engine demands, ie maybe above 3000rpm , but only needs 5volts to start and idle. maybe thats why you dont touch accelarator when starting.

relay £22 from subaru

 

BTTT !

 

Did you get the manuals ?

D

 

sure its not an imobiliser off the alarm doing this

most alarms have a fuel cut on them



tell me to shut up if you like lol

 

It would be worth posting in technical aswell.

D

 

Hi.

I had the same problem on my 94 wrx. Firstly it was because the connector under the back seat had melted a little so bad connection.

Then I got the problem again. D`oh.

This time it was the immobiliser so I traced the wire back from the fuel pump and then took that wire out of the immobiliser box. Managed to see the same colour wire going into the immobiliser box and linked it up to the first... Basically taking the immobiliser out of the equation. Then the car started first time. I did ring the immobiliser company and they advised me under no circumstances that it would be the immobiliser as it had only been on a year... Conclusion is - try and resolve yourself as a company will only want your money or fob you off. Rant over lol.

Hope you get it sorted.

 

BTTT