MPi fuel pump problem

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RS - 19 Mar 2006 19:31 GMT

Also a friend is having trouble with 1998 Mpi non-cooper

normally with key on position number 2 the fuel pump buzzes for a few
seconds b4 you crank (to build fuel pressure). His is not doing this. I
have unboxed the 4 mems relays near the bulkhead in the black box, and
manually moved the fuel pump relay, and we hear a buzz!. So, it is the
"control" side of the relay circuit that is the problem we have deduced. It
is getting the activating 12V from the key switch, but it is not earthing to
activate the relay. The problem is, the earth (black and pruple wire i
think - if anyone is bothered) goes into the ECU with hundreds of wires.
So - i suspect the ECU, an expensive problem i would have thought...

The ECU has anti tamper torx screws, which i have undone, but the case seems
to be stuck together. this is as far as i got - as my friend is worried of
me braking what is already suspectedly broken....

I have heard of people having problems with Mpi fuel mixture -not LAMBDA
sensor - ECU earthing problems, which have been solved by opening up and
attaching another earth wire inside.

was wondering whether there were any wiring techies out there with any
similar experiences. I know mini electircs are dodgy at the best of times,
but i KNOW i have eliminated stupid problems, i have some experience and
plently of diagnostic kit.

sorry for the long one,
RS

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Fitzy - 19 Mar 2006 21:00 GMT

Before you go opening the ECU, check the fuse box,
there is a fuse in there that also controls the main beam (courtesy) flash
from the indicator stalk, this also controls the pump ,
jiggle them about and see what happens,
Fitzy

> Also a friend is having trouble with 1998 Mpi non-cooper
>
[quoted text clipped - 24 lines]
> sorry for the long one,
> RS

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RS - 19 Mar 2006 22:40 GMT

thanks for the info but i did say i manually closed the relay and heard the
fuel pump buzz (ie the fuse is ok). i also said i had norrowed it down to
the earth of the control circuit of the fuel pump relay. I have an
electrical multimeter and a Snap-On power probe, so i am pretty good with
electrics - just not electronics (there is a difference). One thing i did
think of is finding someone with either a Rover or Snap-On fault code reader
and plugging into the ECU

i repeat - this is no silly problem eg fuse/broken wire, tis the ECU
somewhere, was just asking if anyone else has any experience.

RS

> Before you go opening the ECU, check the fuse box,
> there is a fuse in there that also controls the main beam (courtesy) flash
[quoted text clipped - 30 lines]
>> sorry for the long one,
>> RS

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Fitzy - 19 Mar 2006 23:39 GMT

Hi "RS"
what about replacing the missing earth, to the nearest earth point, failing
that,,,,, where are you located,, I have access to a fault code reader,
Fitzy

> thanks for the info but i did say i manually closed the relay and heard
> the fuel pump buzz (ie the fuse is ok). i also said i had norrowed it
[quoted text clipped - 43 lines]
>>> sorry for the long one,
>>> RS

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jsmall@tss.com.au - 19 Mar 2006 22:37 GMT

Not sure about the MPi's, but the SPi's have a inertia cutout switch
that diables the fuel pump in the case of an accident. I've set mine
off a couple of times (BIG pot hole once, and once while working on the
car)

This is a small square box (a little like a relay) with a rubber cover
over the top with a round raised "button" on the top. On the SPi's it
is bolted to the firwall near the wiper motor.

Press the button on the top and see if it "clicks" to reset the switch
and try starting the engine again.

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Fitzy - 19 Mar 2006 23:35 GMT

> Not sure about the MPi's, but the SPi's have a inertia cutout switch
> that diables the fuel pump in the case of an accident. I've set mine
[quoted text clipped - 7 lines]
> Press the button on the top and see if it "clicks" to reset the switch
> and try starting the engine again.

Hi "J" always worth a press on the switch before anything else,
I have a S.P sidewalk , and it has developed a few refusal to start faults
over the years, the most regular being the fuse I mentioned earlier, another
time it refused to start turned out to be the ECU harness plug had partially
disconnected its self,
as a "get you home" repair I connected a wire from the live side of the
numberplate light, up to the pump connection, turn on the lights and off we
go,
the only thing with this repair is that it by-passes the inertia switch,
Fitzy

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RS - 20 Mar 2006 09:45 GMT

hi guys,
it is not the inertia switch, as ive said earlier - i manually closed the
relay (with a bit of plastc), this then put s the 12V through the inertia
switch and to the pump which i have heard working.

Fitzy, i am in Boston, East coast, near nothing so doubt you are willing to
travel (You are from liverpool if i remember correctly?)

cheers anyway,
i rekon my friend will be towing it to a (good) garage later this week, will
post what the porblem was and the fix then.

RS

>> Not sure about the MPi's, but the SPi's have a inertia cutout switch
>> that diables the fuel pump in the case of an accident. I've set mine
[quoted text clipped - 18 lines]
> the only thing with this repair is that it by-passes the inertia switch,
> Fitzy

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Fitzy - 20 Mar 2006 23:11 GMT

> hi guys,
> it is not the inertia switch, as ive said earlier - i manually closed the
[quoted text clipped - 9 lines]
>
> RS

BOSTON.......!!!!????
and you sounded so close ;-)
Regards and good luck
Fitzy

>>> Not sure about the MPi's, but the SPi's have a inertia cutout switch
>>> that diables the fuel pump in the case of an accident. I've set mine
[quoted text clipped - 18 lines]
>> the only thing with this repair is that it by-passes the inertia switch,
>> Fitzy

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