why do my fuel pump relays keep blowing?

ok iv had 3 fuel pump relays blow on me now, if i hold the contacts shut it works and car starts, first couple of times i fitted a new one it worked, then just stopped??

what could be blowing them?

any help appreciated

could be the fuel pump is drawing too much power, or you keep buying cheap rubbish relays

what car is it exactly?

possibly! its a mk1 gti (1800 with a 1600 engine fitted at the mo)

2 gsf ones (worked for a few times now wont unless i hold contacts shut)
and the original one, which has worked but its as if the contacts were stuck shut as he pump would buzz constantly however that wont work now either unless i hold contacts shut.

ok nerxt step i would have a good look at the filler neck and inside the tank, plus check the inlet on fuel pump as per:
The Mk1 Golf Owners Club

ok thanks for the help will try that asap.

rubjonny said

ok nerxt step i would have a good look at the filler neck and inside the tank, plus check the inlet on fuel pump as per:
The Mk1 Golf Owners Club

Hey that's a great thread, very helpful. It's got to worth doing that anyway, maintenance wise.

Cheers for that and thanks to Chudd for posting the OP.

Andy.

In addition to that have you checked your fuel filter?
Mine was full of tiny rust particles too.
No wonder the pump was working hard and drawing too much current.

ok checked tank there are some bits in there but nothing out the ordinary. removed checked and cleaned filter not that it needed it. put sender back in. check fuel pump all good clean. replaced fuel filter engine end.

pit new fuel relay on worked first time second time gone again!!!!

and to top it all off i think the engine gone in my van!! not a good day!

any other ideas?

oh and just on a side note

if i were to put a 16v kr engine in on carbs
would i use a different fuel pump like a facet or something and would that mean id bypass my old pump and relay? or could i? as thats the route i want to go down so might be easier

What rating fuse do you have for the fuel pump?

ahh im not sure? what should it be, il check later

15A I'd guess.

Just wondering why it's not blowing fuses.

Have you disassembled a relay to see what the failure is?

yeh i have took all of them apart, and there seems to be nothing wrong with them? i didnt even think to check fuse? but i havnt replaced one fuse after blowing 4 relays now?

Well the fuse is 15a, I'd have figured the relay can take more than that on the load side, and so the fuse would blow.

I'd be inclined to test the supposed failed relays by probing the switch contacts, and seeing if it works on the bench.

check the contacts in the fusebox too, incase there's a poor connection there.

ok will do - cheers dude do you know which ones the switch contacts are?

according to the manual pins 4 to 6 is the coil, I don't have a relay #2 to hand, so reflect that to the pins on the relay, and probe with 12v to see if the relay closes, then check continuity between the load contacts to check the relay is functioning.

check the socket in the fuse box that the relay plugs into, sometimes the connections weaken and wont make proper contact.

As Racer points out moisture damage corrodes the terminals inside the fuse box.
Later cars had the five pin relay fitted.

if you go for a carb engine then you'll need an fpr, it should take care of the excess pressure from a gti pump but you could swap a facet into its place.

I doubt all these relays are blowing, its more likely the fusebox has poor contacts or there is a problem with the rev counter feed from the coil. do you definitly have spark when this problem occurs, because if not the relay wont do anything

30 - permanent live
15 - ignition live
31 - earth
31b - rev counter feed (pulsed earth)
87 - output to fuel pump

ok thanks for all the help! we have checked everything suggested so far, all points on fuesbox are getting the power they should etc from permanent live, coil feed, ignition live, earths good…

tested the relay outside the car and it does absolutley nothing.

the car definatley has a spark like i say if i hold contactas shut on relay the pump works and car runs until i let go of relay lol


no visable components blown on relay looks brand spanking still!

im worried about getting another relay just in case i blow this one too! could it just be the gsf relays are utter toss?! (should i try another vw relay or is there one from another car i can try ?