PDA

View Full Version : What kills Fuel pump relay's??



v-tec
22nd September 2008, 10:45 PM
Ok for those that dont know my cars been down at a mates workshop for the last month or two whilst getting paint... So its been getting very little movement lately.
It killed a fuel pump relay a while back when it was there, i shrugged and just got another and didnt think much of it

But now we had another problem that it thought might be fuel pump, but its just blown another relay.

Does anyone know what does this?
Nothing has changed on the car that i can think of that would do this, it literally hasnt been touched apart from the occasional start and push for moving around for paint.
The only out of the ordinary thing that has happened is my battery support broke just before it went down there and the battery fell off its perch for a short time....

Any helpful info would be greatly appreciated

Cheers!

Grant

Sprinter86
22nd September 2008, 10:48 PM
I'd crack the relay open a find out exactly how its 'Blown'. I think this would help.

hilux05
23rd September 2008, 04:53 PM
what led you to believe its blown?? pumps not working? melted relay?

my pumps stopped working a while back after sitting around for a while not being driven an all it was was a bad ground..

are you using a proper COR or just 1 or 2 normal relays?

v-tec
24th September 2008, 05:47 PM
Well i blew up a relay a few weeks back, my mate Lee just ran a straigh positive connection (bypassed the relay) to the fuel pump and the car kicked over without hesitation.

So i got another toyota relay from a wreckers which worked as soon as i chucked that in, but then i got told a week or two after by lee (no idea if he had ran it in between then at all) that it wasnt running again.

was thinking fuel pump might have gone or something this time but soon as the positive went to the pump (Again, bypassing the relay) the car kicked over instantly.

Not sure what COR is, but all i can say is its a single toyota one

lowa
24th September 2008, 05:58 PM
i did one a few weeks back and i had a fuse in line that was melted!! get the multi metre out on the relay and where the fuse goes and figure out where the weak point is at......check if the parts are in higher heat areas too maybe if it's a conversion car.

v-tec
29th September 2008, 11:55 PM
After reading someones post in the gze thread, ive got a hunch that the relay is not earthing correctly.
From what i understand the relay actually needs an earth??

I had a play around with things tonight on the car (this is still with the second relay that has seemingly blown), and tryed starting the car.

It kicked over (surprisingly) and idoled for a second or two, and then rev's slowely started to drop and then eventually die. It would continue to do this even if i rev it or play with the throttle a bit... its quite obvious that the fuel supply is just dieing.
And then as soon as i bypass the relay again with a wire straight from the battery the car will kick over fine and idol perfect.

If this sounds familiar to anyone it would be great to know what your solution is.
Also if anyone can tell me the standard wire colour for an earth from a relay it would be extremely helpful so i can try locate the earth point... and earth out this mofo bigtime lol


Cheers guys

Grant

Clinton
29th September 2008, 11:58 PM
black is earth

seek
30th September 2008, 12:01 AM
on rollaclub there is a wiring schematic for ze circuit opening relay, under their FAQ/tech section last i saw.

Sprinter86
30th September 2008, 02:06 AM
It sounds like the relay is powering the fuel pump when it gets the 'crank' signal, but is not getting the earth from the ECU to keep the fuel pump running after the engine has started.


this may help...
http://www.ae86drivingclub.com.au/dcimages/4/8/4/3/177632.jpg


or scrap the toyota relay and run 2 standard relays like so....


http://www.ae86drivingclub.com.au/dcimages/4/8/4/3/177633.jpg


hope this helps!