Fuel Tank obstruction

Post Fri Dec 20, 2013 4:43 pm

Topped up my fuel from a 5ltr Jerry can today, halfway
through a filter came off the metal pipe attached to the can and
slipped into the tank/filler.

Car started and idled perfectly while I nipped indoors, however
as I was returning to the car it stopped running and now refuses to
start. Any idea as to how I can retrieve the filter?

Prior to filling the tank, I carried out the Red/black wire mod
but car started fine after I had completed the mod. Just
thought I'd mention it as every bit of info could maybe relevant.

Car is a 318i M10 auto.

Post Fri Dec 20, 2013 4:45 pm

Is there not an access hatch to the fuel tank underneath the rear seat? I have memories of getting to the fuel tank internals in my old two door this way.

Post Fri Dec 20, 2013 4:54 pm

beemerbird wrote:Is there not an access hatch to the fuel tank underneath the rear seat? I have memories of getting to the fuel tank internals in my old two door this way.

Doh!!!!

I think you are right mate, forgot all about that.

Post Fri Dec 20, 2013 4:56 pm

yeah go in from above the back seat. had an issue like this years ago car just chucked it got it recoverd home and found an extra rubber bottom pad of the pump floating in the tank removed it and jobs a good un.

Post Fri Dec 20, 2013 7:05 pm

You can get into the RH half of the fuel tank by lifting the rear seat, removing the level sender, then the pump assembly, which will give you a hole nearly 3" across. Don't forget that the liquid in there catches fire easily, and that there will be petrol vapour flowing everywhere.
I don't see how anything slipping into the tank can stop the pump doing its job though.

Post Fri Dec 20, 2013 10:10 pm

Brianmoooore wrote:You can get into the RH half of the fuel tank by lifting the rear seat, removing the level sender, then the pump assembly, which will give you a hole nearly 3" across. Don't forget that the liquid in there catches fire easily, and that there will be petrol vapour flowing everywhere.
I don't see how anything slipping into the tank can stop the pump doing its job though.

That's if even if it's made it to the tank, Brian.

Which is why I mentioned the Red/Black wire mod, just in
case by any coincidence it could have any relevance.
Can't see how though as it was running perfectly for a good 3/4 minutes after the mod.

Post Fri Dec 20, 2013 11:02 pm

Rob - unscrew your petrol cap before delving into the tank. I 'think' it's pressurised, and removing the cap will take the pressure off

Can you describe more accurately the thing that fell in?

Post Fri Dec 20, 2013 11:09 pm

Can't you fish it out of the filler neck with a length of wire with a hook on the end?

Post Sat Dec 21, 2013 7:41 am

Wish I could describe the "thing that fell in" Fi.
Hadn't even noticed it when using the jerry can before.
Just happened to notice a small black plastic item,slip off
the end of the detachable filler neck and disappear into the car.
Just thinking, if the item is plastic, or similar, could it dissolve in the petrol
and then block the strainer on the transfer pump?

Only one way to find out I suppose, back seats out.

Maurice, it's a thought, but I could be fishing about for hours/days/weeks.

Post Sat Dec 21, 2013 10:54 am

Narrowest part of the filler is the stub pipe on the tank itself, but this is still big enough to let anything the size of a petrol can spout pass through.
It's highly unlikely that any part of a commercially produced petrol can would be made from a material that's affected by petrol, and the shape/size/position of the pre filter is such that nothing is going to block it.
Whatever is stopping your car from starting is nothing to do with anything that's fallen into the tank, or the red/black wire mod either, unless your car is LH drive.
An engine needs fuel, compression and spark to run. Which one is missing on your car?

Post Sat Dec 21, 2013 11:07 am

My Chinese friend is watching with interest !

Post Sat Dec 21, 2013 11:32 am

Seems to be spark, Brian.
Engine turns over ok.

Have checked fuse 11, can also hear pump priming.

Post Sat Dec 21, 2013 12:29 pm

pacerpete wrote:My Chinese friend is watching with interest !

Not now/yet, Kato.

Have put the battery on charge, just in case.

Post Sat Dec 21, 2013 12:39 pm

Just a thought, maybe it's the automatic gearbox starter inhibitor switch not working properly...

Post Sat Dec 21, 2013 12:44 pm

diable wrote:How old was the fuel in the Jerry can?

Fresh that day from a Shell pump.

Post Sat Dec 21, 2013 1:17 pm

Try spraying some carb/brake cleaner or 'Start Ya Bastard' down the throttle body intake, then cranking it over...

Post Sat Dec 21, 2013 1:30 pm

Car is on an incline and it wasn't a full 5ltr can.

Will wait until battery is fully charged, then take it from there

Post Sat Dec 21, 2013 1:40 pm

Link 30 and 87 of the pump relay, and confirm that it's pumping fuel and pressurising the rail. You'll hear noises from the pressure regulator if all is OK.

Post Sat Dec 21, 2013 2:12 pm

diable wrote:
gooner1 wrote:Car is on an incline and it wasn't a full 5ltr can.

Will wait until battery is fully charged, then take it from there
I drove a car and the fuel gauge was in the red was fine when I drove home. Tried starting it again later in the day and it wouldn't fire up as I where I had parked the camber in the road caused the fuel to move in the tank, 5 litres later all was fine, jack the car up and see what happens.

Quite possible with a 55 litre tank. There's nothing to stop all the fuel ending up in the LH side if parked leaning that way.

Post Sat Dec 21, 2013 2:50 pm

Incline on RH side, car also with tank end lower than engine end

No battery on car atm. Slow charge till morning.
Will then try and start it, if no joy will bridge the relay, then report back on
whatever happens.

Mean while thanks for all the help/advice.

Post Sun Dec 22, 2013 12:30 pm

Ok, reconnected fully charged battery, no joy.
Linked 30 and 37, just a click nothing else.
Also tried 30 and 37b as stated in Haynes, no disrespecct Brian.
Same result. So fault either in pump or wiring to, no?

Slight add on, when doing the Red /Black mod, I forgot to disconect the battery.
Thought I'd better mention it.

Post Sun Dec 22, 2013 12:37 pm

Have you checked all the fuses?

Also, try giving the fuel pump a clout with the ignition on...

Post Sun Dec 22, 2013 12:42 pm

Speedtouch wrote:Have you checked all the fuses?

Also, try giving the fuel pump a clout with the ignition on...

Apart from fuse 11, what other fuse would be relevant?

Oh, I'm all up for clouting it, any specific clout location?

Post Sun Dec 22, 2013 1:12 pm

AFAIK, it's only Fuse 11 that supplies the fuel pump.

Use either your hand, or a rubber mallet or similar, and just tap the top of the pump, start with light taps then get a bit heavier if necessary, but be careful not to break anything!

If you have a multimeter handy, you could check that the pump is getting a live feed with the ignition on - you may also need to crank the engine at the same time...

Post Sun Dec 22, 2013 3:39 pm

Not a peep from the transfer pump.

No multimeter here, Maurice, or knowledge of how to use one.

Do have a known working transfer pump from my old 325i cab though, which,
after a quick check on Realoem, suprisingly also fit this car.
Have to be tomorrow now, fading light and cat weather.

Post Sun Dec 22, 2013 3:42 pm

There is no 87b on the pump relay, unless this is some really ancient set up.

Post Sun Dec 22, 2013 3:52 pm

It's an19 87 m10 318i AUTO, Brian.
Definitely has an 87b.

While I'm here, what is the correct way to remove the fuel hose clamps
from the transfer pump, sounds stupid I know but....
Also, I take it I don't need to depressurise the fuel system, or do I?

Post Sun Dec 22, 2013 4:14 pm

It is an ancient set up then! Fuel pump relay and what can be loosely defined as the DME relay are combined into one unit.
30 to 87b should work the fuel pump when linked together on these. 30 and 87 is for the injectors. If 30 to 87b doesn't turn on the fuel pump (ignition switch on or off), then find out why.

Post Sun Dec 22, 2013 4:33 pm

Just to clarify, Brian, I'm looking more to the fuel pump itself,
not the transfer pump

Post Sun Dec 22, 2013 4:38 pm

If power is getting to the pumps (unknown immobiliser?), then the main pump is more likely to be the problem. The main pump should still pump fuel, although noisily, without the aid of the transfer pump. That's assuming the pick up is actually immersed in fuel, of course.

Post Sun Dec 22, 2013 7:53 pm

So after another quick check on Realoem, it turns out
that the main fuel pump from my old 86 325i cab is the same
part No as my M10 one.

As I know this is a good working one, I'll try a quick swap tomorrow.
Realise that it's not the right way to go about fault finding, but
at least it may eliminate the problem for now. God bless BMW.

Fuel is half way between the qtr and empty, so don't think
that is the problem but will try to move car manually, if only to eliminate that query too.