No Power To Fuel Pump.

[macaroni 17 1 Cars]

My 205 mi16 has not been able to start for a while, and I've tracked it down to the fuel pump not working.

The pump does work with a direct live AND earth feed and the car runs till the fuel in the rail runs out.

 

However, their is no power to the live feed when cranking and even when I put a direct live feed to the pump, I have to earth it to the battery the live feed comes from.

 

I even tried earthing it to an existing earth point, to no avail. This seems very odd to me.

 

I've replaced the fuel pump relays and there are no blown fuses in the glovebox.

 

Can anyone please suggest something else to try or a possible solution?

 

Thanks in advance.

 

Antony

[gaz832 7 1 Cars]

My 205 mi16 has not been able to start for a while, and I've tracked it down to the fuel pump not working.

The pump does work with a direct live AND earth feed and the car runs till the fuel in the rail runs out.

 

However, their is no power to the live feed when cranking and even when I put a direct live feed to the pump, I have to earth it to the battery the live feed comes from.

 

I even tried earthing it to an existing earth point, to no avail. This seems very odd to me.

 

I've replaced the fuel pump relays and there are no blown fuses in the glovebox.

 

Can anyone please suggest something else to try or a possible solution?

 

Thanks in advance.

 

Antony

im having the exact same problem , im also using a switch in the car for the pump to run, what fuse in the glovebox works the pump mate. mi16 car also

[Toddy 7]

My 205 mi16 has not been able to start for a while, and I've tracked it down to the fuel pump not working.

The pump does work with a direct live AND earth feed and the car runs till the fuel in the rail runs out.

 

However, their is no power to the live feed when cranking and even when I put a direct live feed to the pump, I have to earth it to the battery the live feed comes from.

 

I even tried earthing it to an existing earth point, to no avail. This seems very odd to me.

 

I've replaced the fuel pump relays and there are no blown fuses in the glovebox.

 

Can anyone please suggest something else to try or a possible solution?

 

Thanks in advance.

 

Antony

 

From memory the MI loom has a seperate fuel pump relay (brown I think) you can operate this manually to test your wiring.

 

As for the earth, I think the pump earth wire is near the NSR rear lamp unit, clean up the earth straps in the engine bay.

[gaz832 7 1 Cars]

From memory the MI loom has a seperate fuel pump relay (brown I think) you can operate this manually to test your wiring.

 

As for the earth, I think the pump earth wire is near the NSR rear lamp unit, clean up the earth straps in the engine bay.

that wouldnt be the yellow connector next to the passenger rear light. ?

[macaroni 17 1 Cars]

Not sure which fuse it is, but they're all OK. Cleaned as many earth connections I could the other day, including the one by the rear light. Strange that I could only earth it to a battery and not even an earth I know works ok. Unless I'm missing something fundamental!

[gaz832 7 1 Cars]

is this the rear light point as i took the rear lights off during the week to find this mess and the white block with yellow connector snapped of its mounting point.

is that the earth point ?

Edited October 8, 2011 by gaz832

[macaroni 17 1 Cars]

That's it and that does look grim! Mine is perfect-looking, unless there's a broken wire somewhere.

[gaz832 7 1 Cars]

some of the rear lights wiring i have to sort out. any ideas how i can bolt the connector back to the car as the place its meant to be is rusted to bits.

 

this is my switch to put the fuel pump on.

[dcc 855]

Your earth from battery to inner wing is s*it. make it better. no other reason why the earth to chassis next to the pump wouldnt work. prob why your pump isnt working too. are your lights dim'ish?

 

make sure you have a lovely contact with the chassis leg else you'll be pissing into the wind, again.

[Toddy 7]

that wouldnt be the yellow connector next to the passenger rear light. ?

 

Yes

[gaz832 7 1 Cars]

yeah the lights arent too great actually, any ideas how i can attatch the earth to the rear, wont go back in the same place as its knackered.

[macaroni 17 1 Cars]

Well just checked my nsr rear earth point again and its in excellent condition, as are the ones on the nsf inner wing.

 

Still no fuel comes out of the feed pipe when cranking.

 

Any more places to look for an electrical glitch to the fuel pump?

[gaz832 7 1 Cars]

Well just checked my nsr rear earth point again and its in excellent condition, as are the ones on the nsf inner wing.

 

Still no fuel comes out of the feed pipe when cranking.

 

Any more places to look for an electrical glitch to the fuel pump?

how have u got your nsf earth mounted, do you have it on the plate where the ignition module is. ?

u can just make out mine on a plate where the ignition module is attatched to .

Edited October 8, 2011 by gaz832

[Anthony 1,003]

Some Mi16 looms have a separate fuel pump fuse next to the relays in the engine bay - this is usually 10A and thus tends to blow before the 15A one in the fusebox.

 

Also, Mi16 looms are generally in pretty poor state these days, and I've seen several that have broken wires off from the underside of the relays due to corrosion and vibration.

 

Plus, there's always the usual favourite - a shoddy installed immobiliser that's playing silly sods. Fuel pump feed is usually one of the two circuits that is immobilised.

 

Failing that, it's time to dig out the multimeter and keep working backwards until you find where you do and don't have power - once you've done that, the problem is normally obvious enough.

[macaroni 17 1 Cars]

Gaz, my nsf earth is mounted on the same plate as the ignition module (which I just replaced). I removed it, cleaned the contact with the inner wing and the contacts with the earth straps.

 

Anthony, this motor was yours and you said the loom was put together by Sandy, so it should be OK. I will check the fuel relay contacts with a multimeter tomorrow, but they do click when the ignition is turned on.

[Anthony 1,003]

I know that, but the bits that tend to fail on the looms aren't bits that are typically touched when they're converted for 205 use - it was fine when I sold it, but clearly it's been in your car and fitted for a while now, so it's entirely feasible that vibration or exposure has taken its toll.

 

Worth checking as it's becoming an increasing problem as the looms get old - they're almost all 20+ years old now after all, and to give you an idea, I've got two Mi16 looms sat in the corner of my living room awaiting me finding the time to fix the exact issue I described above, and I did another for someone earlier this year that had failed in the same manner.

 

(if yours is alright still and not corroded, it might be worth smearing a little vaseline or similar around where the wire meets the pins to prevent corrosion taking hold)

[macaroni 17 1 Cars]

I've checked the wires to the relays and they seem fine. Question; should both click with the ignition? Only the outside one (nearest the wing) does.

I delved into the fuse box and found a black inline fuse, that when I unplugged and plugged it in again, caused the same relay to click. So I deduce that the fuse is OK. There is an inspection hole in the side and the wire looked intact anyway.

 

The red wire that goes into that fuse, from the fusebox, rather than the engine bay relay side, has a 12v feed with the ignition on. So there is power there.

All the fuses are OK, but I still have no power at the fuel pump with the ignition on. There is power to the fuel gauge sender connection.

 

The red wire that goes into the inline fuse seems to go to a yellow plug in connector in the fusebox lid, which seems fine. So is that connection protected by a relay or a fuse and if so, which one?

 

I feel I am getting closer, but I'm just hunting in the dark now.

 

Thanks for your continued help.

 

Cheers,

 

Antony

[Toddy 7]

Open up the relays and check that they are energizing with the ignition on, if they don't you can manually operate them with a screwdriver etc.

 

You really need to use a multimeter then its a 5 min job to diagnose the problem, otherwise you are pissing in the wind.

 

Let us know how you get on.

Edited October 9, 2011 by Toddy

[james_pug 26 1 Cars]

Do you no which wire it is off the relay to the fuel pump? If so check continuity from there to the pump could be a dodgy connection somewere along it's run.

[Anthony 1,003]

From memory, one relay comes on with ignition (which powers the ECU etc) and the other comes on when the engine turns over (the fuel pump relay)

[macaroni 17 1 Cars]

I am using a multimeter and I'm still pissing in the wind!

 

The relay is being energized with the ignition, but I didn't check the other one with cranking.

 

James, that is where I get lost. I thought I had the right wire, then chased it to the back of the stereo - D'oh!

 

If the relays are clicking, both in the fuse box and engine bay, but the pump has no power, I guess the problem must lie in between. (I'm dead clever me...) but the cabling through the car seems to go near the central tunnel and hard to get to.

 

Thing is, it worked fine one day, and wouldn't start the next. Can a wire break overnight?

 

I'm sure I'm missing something somewhere but I'm damned if I know what.

[gaz832 7 1 Cars]

i have my fuel pump going again , i fiddled with the relays fuses, put the rear lights back together and attatched the earth on the nsr light up. car still wont fire up tho, but i have a great spark from all the plugs .

[macaroni 17 1 Cars]

Argh, this is really getting me down now. I have power at all the relays and a seemingly good earth.

 

I get 0.8V across the leads to the fuel pump with ignition on, this isn't right surely?

 

I was wondering about a new pump, but given a direct power feed, and earth, from a battery it works fine. It just isn't getting any power from the cars power source.

 

Anything else I could try?

[Anthony 1,003]

If the pump works fine off a battery, then the pump isn't the problem.

 

If you definitely have power from the fuel pump relay when cranking, first check for power at the brown plugs under the dash (white wire 74 on the smaller of the two plugs) and for power at the fusebox on the 15a fuse nearest the driver. Put one end of the multimeter on the fuse or connector pin, and the other to an earth point or clean bolt that goes into the chassis/metalwork - you'll see something like 10-12v when cranking if there's power there.

 

(you won't see anything at ignition on, as the pump only gets power when the ECU senses that the engine is turning)

 

Also, check that you've got continuarity (sp?)between the earth pin on the fuel pump connector and the earth point / chassis just to rule that out.

[Toddy 7]

A non working CPS will not inform the management that the engine is trying to be started, this may be causing the problem , therefore have you got a spark at the plugs?

 

Ignore the above as I see you stated the car runs if you provide the pump with a direct feed.

 

You need to be cranking the car over when checking the fuel pump wiring, are you getting any voltage 1) before the relay? 2) directly after the relay? 3) check the wire directly after the relay to the pump for continuity?

Edited October 13, 2011 by Toddy