M42 Fuel Pump ....Help

[no1_jazz]

Evening Zoners”¦

Here I have two fuel pumps which once upon a time worked fine ”¦ the one on the left was the original one which came with the car when I bought it and after that gave way I got the one on the right with the black foam cover around the pump from my local breakers.



left pump (initial original) right pump (bought from local breakers)






left pump Bosch .......... right pump dunno spotted no print on it.

The first one was working fine up until it just stopped working”¦. So went to my local BMW breakers and bought another and it’s been working fine for the past year only up until now it’s stopped.

Both pumps when working worked fine. What is the difference between these two pumps as you can see visually they look different?

Problem is that the car cranks away however dose not fire up. My initial thought was that my fuel pump relay had gone again as it did a while back checked that and it seemed to be fine.
I have checked power going to the wire that powers the pump seems fine. Upon turning the key I do not hear the pump spin as it usual.

The most baffling thing is that I took the pump out (black foam)connected 12 direct to it and it seems to spin however sounds unhealthy then did the same to the one which had been sitting in the garage for the past year (original one) and guess what spins away.

All help and advice is much appreciated.

Jazz

[daimlerman]

I had fuel pump issues a few weeks ago,I discovered that the fuel pump will run with the live feed connected to either terminal,or it can be wired to blow as well as suck....as the actress said to the bishop....took me ten days(I had man flu as well)to find out what I had done.

[no1_jazz]

daimlerman any idea what the difference is between these two pumps?

[Brianmoooore]

I've come across the foam covered pump in a few late E30s. I presume it's just an updated model.
I've found that a used pump should always have some oil dripped into it if you intend to put it into long term storage to prevent internal corrosion, which makes it stick.
It's impossible to say from here whether either of your pumps are faulty, or whether you have a problem with your electrical supply to them. A pump with always sound somewhat unhealthy if you run it dry.

[no1_jazz]

Apologies for the late reply guys and again for the limited information i have provided, my minds been a bit everywhere busy with work and xmas preparations. Ive been away from the motor since i last posted on this thread.

Anyway a day off work today and tomorrow (thank god).....today before getting a new pump i tested both old pumps by connecting direct 12v to the pumps and nothing at all. just a clicking noise for a few seconds, no spinning no nothing.

Right guys so i managed to get a new pump today....installed it right away fiddled around getting it into the tank. Connected fuel pipes as they were previously upon disconnecting it.

Turned the ignition on and i did not hear the pump spin as it normally should do and at this point i was thinking hell nooo. Tried starting it and to my misery again was cranking but not firing.

sprayed a little easy start directly to the throttle body and it attempts to fire started for literally for a second and cut out again. Checked my fuses they all seem fine.

Brianmoooore thanks for the advice mate.

Guys i have very limited knowledge about checking on electrical faults so please do bare with me.

Could anybody shed a little light on what to do next and how to go about it.

all advice is much appreciated

Regards
Jazz

[Brianmoooore]

Pull the plug off of the pump, and connect a 12 volt 5W or 21W bulb to the plug.
Check that the bulb lights when you crank the engine.
If not, check fuse 11 very carefully, or swap it with another 7.5A fuse.
If the bulb still doesn't light when you crank, pull out the pump relay, and link together pin 30 and 87 of its base with a piece of wire. Bulb should light without cranking.

[no1_jazz]

Brian i will give it a go tomorrow and keep you posted on how i get on.

Thanks allot for your help and time.

Jazz

[no1_jazz]

Right as it follows...

I Pulled the plug off of the pump, and connect a 12 volt 5W bulb to the plug.
Cranked the engine no light to the bulb.

Checked Fuse 11 lights up with ignition on. Seems fine no split in connections, swapped it with another 7.5 and still nothing.

so i then pulled out the fuel pump relay, and linked together pin 30 and 87 of its base with a piece of wire. Bulb did not light up.

[daimlerman]

Fuel pump feed wire is green/violet.

Runs from fuse 11 to FPR,then via the wiring duct under the fuse box into the car interior,down the void just forward of the A pillar to the l/h sill,along the sill to the rear seat pan,then to the fuel pump.
Joining 30/87 of FPR and no action at the pump would indicate a break in this wire.
If the pump had sprung into life,we would be pointing you toward the CPS....please shoot me with consideration!

[no1_jazz]

cheers daimlerman tried fitting a new fpr but still nothing so yes i will check this out as soon as i can and get back to you to see if there is any break in the wire.

whats the CPS??

[daimlerman]

whats the CPS??

Sorry!

Crank Position Sensor.

Mounted at the front of the engine close to a toothed wheel with one tooth 'missing',it tells the engine ECU exactly where the crank is,to enable it to fire spark plugs and inject fuel at just the right time.

So if the fuel pump is switched on by the relay,or by shorting the relay,and the engine does not want to play,this must be high up the 'suspect' list.

In your instance,it looks to me as if the fuel pump is just not getting power,perhaps a check would be to run a temporary feed direct to the fuel pump? Bear in mind if you try this that the pump is capable of running both ways!

[no1_jazz]

Thanks i hope its not the CPS and yes i know exactly where it is.

I am presuming that it is a faulty wire which may most likely has a split somewhere along the way as there is just no power going to the pump whatsoever.

I have read up somewhere that it is with great caution when putting direct power to the fuel pump as it can as you state run in both ways.

so far thank you all for the help it is greatly appreciated.

regards
Jazz

[Brianmoooore]

If the bulb didn't light when you linked 30 and 87 of the pump relay base, then there is a problem in the wire between this relay and the pump. Don't get distracted by irrelevant things, such as the CPS.
Next check is to remove fuse 11, connect your bulb between the inner socket of this fuse and earth, and to fit the wire link on the pump relay base again. With some types of fuse you can make contact with the actual fuse wire in the fuse without removing it. Bulb should light.
All the above assumes, of course, that you are performing the tests correctly.

[no1_jazz]

Guys after everything I had given up”¦ still wondering why is it that I’m getting no power to where it’s needed. In my efforts to follow your instructions I can say I followed through exactly and while conducting your advice I had found a few faults that I was able to rectify with your help and guidance.

Pondering over this situation over and over and not getting anywhere, I thought it was time to call the A-Team (My Father and his good old friend Mr Singh). Lol

So I passed the keys to my dad and his friend. They are both notorious in the auto mechanical and electrical field as they both once where working in and around a dozen of these cars back in their earlier days.

I fully explained the problem and then explained the steps which I have carried out all thanks to you guys. They were somewhat surprised as to where and how I knew what to do. I told them all thanks to the e30zone which is an internet forum full of enthusiasts with experience and knowledge.

Right after handing the keys to the oldskool crew, I ran in the house to make some desi cha (indian tea), they ran all their checks from the pump to the fuses to the relay and then followed through to the battery. They found that the + Battery terminal was loose, pulled out the ratchet tightened it all up. Connected the fuel pump and put the relay back in.

Turned the key and fired up straight away.

At this point, I come walking out with the tea and I see them and my car nowhere to be found”¦. Turned out the went for a little drive and bought back some rich tea biscuits”¦five minutes later the doorbell rings and there they stand laughing”¦.mumbling between themselves ( youngsters these days )

So there we have it guys just goes to show I had overlooked the simplest basic steps, however it didn’t come to mind to check the terminals as the car was ticking over. (To say I had a blonde moment is somewhat an understatement) lol ”¦”¦ So a basic lesson to be learnt here is to start off checking as they describe the powerhouse (battery) and follow it through. Any and all power is to come from the battery then distributed where needed.

What an eventful evening that was”¦..

Thank you both daimlerman and Brian ”¦. And not forgetting my Father and his good friend Mr Singh!

[daimlerman]

I guess that both Brian and myself would assume that the battery was properly connected....

but I live and learn every single day,here!

[Brianmoooore]

I guess that both Brian and myself would assume that the battery was properly connected....

but I live and learn every single day,here!

I've learnt never to assume anything! If the last tests had been performed, the bulb would have remained unlit, and the next test would have been to connect the bulb between 30 of the relay and earth. This would have also resulted in an unlit bulb, and since there's nothing between pin 30 and the battery other than thick red wire, the battery terminal would have been where the OP would have been directed to next.

[Jos]

There's method in the... erm... method!

Glad it's working again though, nothing worse than a non-runner (except a dropped valve I suppose:))

[no1_jazz]

Thanks Guys”¦..

yes about the battery reason to why it didn't occur in my mind to double check it was because the car was cranking healthy an all electrics in car lights”¦ head lights”¦. Music the lot was working so I automatically assumed all was connected properly but I guess not ”¦..

Yes it’s a learning curve and in my eyes I am forever learning. It feels good to turn the key and start the engine well I guess that’s the norm but it’s been a fair few weeks where by the car has just sat in one spot sleeping on the drive.

Thank you all again for all the contributions

Greatly appreciated.

Jazz

[Brianmoooore]

The engine loom has its own feed from the battery terminal, separate from the feed to cabin controlled electrics. Both of these bolt onto the battery terminal clamp itself, and it's this connection that was loose or not making contact.

[no1_jazz]

Brian i am as always forever learning thank you for clearing this up for me.

I sure damm will not fall into this trap of confusion every again.