daz-cos

hi all just looking for a bit of advice with a problem im having with my 2wd sapph,
right i rewired the pump a few years ago using the drawings on here and alls been well untill about a month ago my car refused to start, i traced the problem to a knackerd relay on the old wiring (now being used to triggar the new relay)new relay all sorted. about a week later it cuts out while driving same problem so i got another relay from a different place thinking i might of been of poor quality, nope week later same again. this time i linked out the old relay as not really needed now, now the cut out in the boot keeps tripping so im wondering if the pumps on its way out, so thort id ask on here first before buying a new pump only for the problem to still be there.

thanks in advance
daz

daz-cos

Anyone

English

You poor fucker, and no one wants to help cos it's electrical and everyone hates electrical cos it's usually an arse!!!

If you are savvy with electrical, possibly check your fuel pump's resistance across the terminals. This will tell you if there's any breakdown in the motor windings. I don't know what resistance you should expect to see. Nerds? Help please? Sure you could google it.

Tell us what pump you have too as that may affect the resistance.

If the relay is tripping, usually it's because there is too much current somewhere in the system. Alternatively, it could be a faulty, relay.

What size wires do you have, and what size fuses do you have protecting the control circuit, and the feed to the pump? These need to be right OR YOUR CAR COULD CATCH FIRE!!!

Another thing you could do is test the resistance of the circuit that goes through the boot relay. Or test the resistance between a good earth on the body of the car, and the terminals of the boot relay BUT!!! Before you do this, set your multimeter to DC Volts and test ALL the terminals to make sure you don't test between a live terminal and the car body, which will short your multimeter.

If you don't know what you're doing, get an auto sparky. They are cheap when you consider the time they save, the inconvenience of your car cutting out, and for peace of mind. They have diagnostics and experience.

Tell us the spec of your car too. Might be the pump is maxxing out or something...HATE these bloody problems haha, but you will get it fixed, so try to keep smiling

daz-cos

Spec is basically stage 1 but with a t34 was set up at Nms late last year so think the standard pump should b ok for that. As for wiring I used 6mm with a 20a fuse think the old wiring is also on 20a, but it's blowing 40a relays thing that's confusing me is if it is the pump then surely it should blow the fuse on my new loom as ther is no load on the old loom as its just a triggar now. Anyway I'll try your suggestions and report back, I'm on hols next week so if I do t sort it by then I'll take it to Nms as its due a service anyway.

Cheers for ya help
Daz

rinus_2005

iTrader: (1)

Have you checked the wiring on damage/shortage and resistance? If all seems oke, than the fuelpump is deffo suspect.

martysmartie

iTrader: (1)

I would say excess current is the problem, this could be due to bad wiring or a partially seized pump.

Where abouts is your fuse located, it should be as close to the battery as possible, hopefully you haven't got it after the relay?

The switch should be cutting out though, as only inertia would cause this.

Martin

daz-cos

Iv checked all my wiring and all is ok iv mounted my fuse on the scuttle above the batt so should b ok an it is befor the relay. I also think its exces current causing the problem but it's the old wiring that's got the problem not my new stuff, do you think could be a faulty cut out if u say should only cut out due to inertia? I just think if it was the pump then wouldent it blow the fuse on my new loom?

Cheers for the input guys

cossie330

iTrader: (1)

so your cars existing relay which used to switch the pump now switches another relay which switches the pump, but its the cars existing relay thats blowing. if so i doubt that theres anything wrong with the pump as the load for that doesn't go through the first relay

martysmartie

iTrader: (1)

Actually yes, good point, when you think about it!

Ignore that, it's only minimal current passes from the 'trigger' relay used to power, the now new fuel pump relay.

So perhaps it's a wiring problem on the old wiring which powers the relay you are having trouble with?

Yes the cut out switch does one job only and that is to open in the event of an accident, it can and never will do anything else, so it seems strange yours is opening, so perhaps that is faulty as well?

Martin

daz-cos

exactly that.
took it for a drive last night, was out about an hour with no problems would normaly have cut out atleast twice in that time maybe iv inadvertantly cured it by pulling it all to bits an putting it back, still confuses me why the fuse has never blown, will be of out in it friday so ill see what happens. still be of to nms for service so il get him to check it while its in

cheers daz