360 fuel pump issue

Hey guys ive got abit of an issue thats doing my head in , im thinking relay but thought i would get some opinions and ideas first , plus i need to find a relay if it is ...

i bought the car non running with a dead fuel pump but it came with a new one , i installed that and got the car running perfect no issues at all turned it off went in for the night came back out in the morning tried to start it and nothing it just cranks , the fuel pump isn't pumping at all there's no sounds etc
it was quite loud and you could feel it running before ...

now first thing i checked for was 12v ... it has 12v when the car is being kicked but it doesnt start the pump, when we had the car running previously it would quickly prime on reds then pump while being started now we are getting nothing
all wires are tight etc and its reading 12v ,i connected the pump straight to a battery to see if it would work and it started pumping fine .
so, why is the pumps 12v supply not engaging the pump?
could the relay be stopping it ?
im not completely sure how that crap works haha

its killing me i have checked every wire and replaced every fuse and have come up with nothing the last thing i have is its a bad relay, i cant hear it click at all but i also dont want to rush out and buy one incase its not that , 360 stuff has been a pain to get .

any help at all would be great ive run out of ideas i had another old volvo bloke here stumped too hes thinking the relay but he thought if it was dead it wouldn't be reading 12v at the pump when cranking it would just have no 12v and there's our problem ...

Comments

  • If you're getting +12V to the pump, how's your ground connection at the pump?
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  • pigdogdave (@pigdog) Wollongong NSW
    If you're getting +12V to the pump, how's your ground connection at the pump?

    Ok was just under the car with the mutimeter to double check everything i sent my mate under last time its not reading 12v , its showing power with the test light so he assumed its got 12v its something real low like 0.3 on reds and 0.1 on firing .
    im guessing relay ?, 240 wouldnt have the same one in there would it i could use to test ? i dont have spare money to be buying relays in hope its that this time of year is brutal
  • pigdogdave (@pigdog) Wollongong NSW
    ok more stuffing around and i gave up looking everything seems fine so i removed the pumps wires and ran my own straight to 12v and good earth annnnnnnnnnd nothing ..
    the pump no longer works, the car came with this pump partially installed and they had it wired the wrong way around it was sucking not blowing i put it around the right way and it fired right up, could all their attempts have burned out the pump? could something else be killing the pumps ?
    i don't want to rush out and buy a new pump if something else is causing the issue and is just going to kill this pump.
    im trying to contact the original owner to get some ideas of the problems they had and things they tried cause everywhere i look someone else has been, fuel pump relay is all scratched up and cleaned same as its fuses and wires someone has been here chasing the same thing i am .

    fuel pump fuse was meant to be an 8 amp it was a 25 i removed it and put a new 8amp in could it have overloaded the pump?

    this is killing me i just want this nugget on the road already
  • Hi Dave, I have owned five 360 Volvo's over 33 years and they all have pulled the no fuel stunt on various occasions mainly due to corroded connections. Firstly I suggest you check the fuel pump fuse situated between the battrey and the inner mudguard. There are two fuses, one for the fuel pump and the other for fog lights. This fuse is usually the problem. Clean all the contacts and provided that all the wiring is ok the car should start. I have had only one fuel relay which had to be replaced. It had become damp somehow and the contacts inside were grotty, cleaned them up and the relay has been in use for ten or so years. How do the fuses behind the battrey get wet? Look where the mudguard is bolted to the inner guard with the bonnet up. Some 360's have drain holes next to the bolts right above the fuse box. Seal the holes with filler, sand and paint etc. Also check under the battrey for rust. Water leaks from around the mudguard screw area which collects under the battrey. Have fun! Laurie
    egads
  • they had it wired the wrong way around it was sucking not blowing i put it around the right way and it fired right up, could all their attempts have burned out the pump?

    Yes. Very possible. They're designed to cool themselves by the flow of fuel through them. If the pump had run backwards for some time, so it blew into the tank instead of sucking fuel from it, then it has probably run hot and cooked itself. And that sucks. You shouldn't have any problems with a new pump if the polarity is correct, the fuel is clean and the lines are clear.
  • pigdogdave (@pigdog) Wollongong NSW
    Hi Dave, I have owned five 360 Volvo's over 33 years and they all have pulled the no fuel stunt on various occasions mainly due to corroded connections. Firstly I suggest you check the fuel pump fuse situated between the battrey and the inner mudguard. There are two fuses, one for the fuel pump and the other for fog lights. This fuse is usually the problem. Clean all the contacts and provided that all the wiring is ok the car should start. I have had only one fuel relay which had to be replaced. It had become damp somehow and the contacts inside were grotty, cleaned them up and the relay has been in use for ten or so years. How do the fuses behind the battrey get wet? Look where the mudguard is bolted to the inner guard with the bonnet up. Some 360's have drain holes next to the bolts right above the fuse box. Seal the holes with filler, sand and paint etc. Also check under the battrey for rust. Water leaks from around the mudguard screw area which collects under the battrey. Have fun! Laurie

    the fuse behind the battery is fine and been replaced anyway all the connections are good and power is flowing thru the relay did look pretty nasty but i got another relay yesterday and ive still got no start .
    im lost on whats going on , i pulled the pump back out and bench tested it and it started pumping again theres no 12v getting down to the pump.
    they had it wired the wrong way around it was sucking not blowing i put it around the right way and it fired right up, could all their attempts have burned out the pump?

    Yes. Very possible. They're designed to cool themselves by the flow of fuel through them. If the pump had run backwards for some time, so it blew into the tank instead of sucking fuel from it, then it has probably run hot and cooked itself. And that sucks. You shouldn't have any problems with a new pump if the polarity is correct, the fuel is clean and the lines are clear.

    that was my original thinking but i pulled the pump out and bench tested it , it started pumping fine ...



    its going to be something small and stupid but its unfortunately still smarter then me cause im stumped , ive gone over everything 100 times and it all looks fine im at the point where i really need someone who knows what the hell they are doing and looking for im winging all this shit and learning as i go and can usually work it out but this one has beat me
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