Need a new bypass valve by the looks of it - getting the dreaded 'yo-yo' on acceleration - its fine if I feather the throttle very gently and drive like I'm running on reserve tank - not looking forward to this job - its like a sauna outside here these days - long summer break with the car parked outside for 6 weeks has taken its toll obviously. Battery was also completely dead when I got back from old blighty.

Downloaded instructions from the Detroit Tuned link on here and watched the ModMini video on this - he always makes it look suspiciously easy though

As usual any advice welcome fellas.

 

never mind. wrong diag

 

 

Quick update - it now doesn't start up at all. Pulled the plugs and checked them - looked fine. Cranked it over and all four were sparking fine. But couldn't smell any petrol. Popped the back seat off, unbolted the fuel filter cover, which was sealed so perfectly and tight, and low and behold the filter housing had what looked like an original factory seal on it- thin paper strip - so had probably never been changed out in other words.

By now I was very suspicious this could be the cause, as I could hear the fuel pump was working. Anyway changed the filter out for a new one, removed the black petrol from the filter housing and tried again, but still no luck. Popped the plugs out again and tried cranking it, but still no smell of any petrol. I popped the fuel line at the connector by the fuel rail and it was bone dry. At this point I was sure it had to be the fuel pump. Popped the fuel line off the top of the filter housing again and not a drop or even a wiff of fuel.

So replacement fuel pump it is then - i hope this will cure the engine running/idling rough, random stalling, and hesitating under acceleration etc.

Does anyone know if the R53 JCW has the same fuel pump as the standard Cooper S ?

 

Here is a thread by a guy doing this same things that you are. Maybe PM him...

https://www.northamericanmotoring.co...ml#post4490449

 

Awe, Eddie, you're so sweet! LOL!

AFAIK the JCW and the Cooper S do have the same fuel pump. It's the S/C, the injectors, and the tune that are different. Fortunately my local parts guru could get me an OE VDO fuel pump for less than the Chinese aftermarket junk.

Did you replace the entire filter assembly, or did you get just the filter insert? Prices on the danged filter assembly are worse than the fuel pump!

 

Hmmmm....
Sweet?
That’s me...

 

This is the original filter from the factory- 13 years old - BMW have a ton of service history on this car- but never changed the fuel filter- not even one time

Thanks - yep every one of the fuel pump pics I have seen over 2 days all look exactly the same- some are green tops others white being the only difference. And I only replaced the filter element

 

Right here's the latest twist - the replacement fuel pump arrived so I got straight in there- whipped the old fuel pump out and I was expecting lots of fuel in the pump assembly after watching videos of others changing these fuel pumps- but there was hardly any fuel in it - and what was even worse was the fuel tank was totally empty !!!

Now thinking back the gauge was showing a good quarter tank full. I'm suspicious that the actual problem was no fuel and a dodgy fuel gauge- which has played up once before when it refused to work at all.

Anyway filled the tank with 20 liters and popped in the replacement fuel pump with a new rubber seal - after filling the pump assembly with fuel- and tried starting it - nothing doing. Even after a good few minutes of trying - still nothing!!

i unclipped the fuel line going into the top of the fuel filter assembly and it was still bone dry- tried blowing into it and nothing- tried sucking and got a mouth full of fuel - I'm assuming it has a one way valve in it somewhere.

next unclipped the fuel return line near the fuel rail on the engine mount side, and again bone dry.

Question- If the tank runs down completely empty- could that cause problems like this ??

need your help here guys running out of ideas.

 

Do you hear the pump run when you turn the key to the on position? You should hear it hum as it primes the system before the engine turns over. If you don't hear it priming the system time to check fuses and relays to make sure it's getting power, as well as testing power and ground circuits at the fuel pump connector.

 

Yes I can hear the pump priming when the key is turned to position 2 and the dash lights up- and it starts up again as you start to crank the engine. But no fuel coming through to the fuel filter housing

 

Ok here's the latest- mini got transported to a local garage - they do European cars mainly- good reputation- they tried linking to the ECU through the OBD socket in the usual way- but they say they can't link to the ECU to get any codes - does that sound right ?? They have tried all 4 of their code reading devices and nothing- they reckon they've worked on minis before but this is the first time this has happened-

What could be wrong guys?? !!

 

Only thing I can think to do is to simply trace wiring for the socket and ECU.
Only thought is that someone at one time tried a piggyback ECU solution or stand alone, that somehow required the sockets disconnection and never reconnected it.
Sorry but my only thought.

 

It seems that the OBDII port is a different problem. The car was running. Then it wasn’t. Investigated and found no fuel getting to the injectors. And the new pump runs when it is supposed to, but still no fuel getting to where it is supposed to go. It seems that the ECU is doing its thing and is fine.

I’d go back to this post about the new pump running but...
If the pump is running, it should be pumping. If it isn’t pumping then the pump is bad (not likely; pump is new, right?) or there is something blocking the inlet or outlet or there is a major leak somewhere. Is there a way to test the pump by itself?

I know I am being simplistic here. Sorry, but I don’t know the system well enough to give specific comments only general comments as to the approach I would take.

 

You said it didn't start even after a few minutes. Was that cranking the starter, or just cycling the key? If you ran bone dry, then you will need to cycle the fuel pump several times to get sufficient fuel and pressure throughout the system before it will start. Turn the key on, but not to start. Leave in on until you hear the pump stop. Turn key off, then back on again. Repeat this process several times, then try to start.

If thst doesn't resolve it, you might have a bad pump. You could swap your old pump in and see if that resolves your no-fuel problem, since it is possible that your pump wasn't bad, but your tank was dry.

Pretty basic suggestions, but that is all I can offer.

 

Another obvious, but must be asked question, is the tank simply low?
The Mini tank is actually a split saddle design, while the divide isn't very tall, it is still there, and the level bob is on the filter side, not the pump side.

 

Are you sure you got the fuel line hooked up in the tank that runs to the filter assembly? Is that hose/line in good shape and not damaged? You may just be pumping fuel back into the tank.

And there is a level sender on the pump assembly as well as on the filter assembly for an accurate reading. Have you checked both sides of the tank and made sure the levels are equal? This could clue us in on the hose being good or bad if you're just transferring fuel to the other side.

 

Thanks for the suggestion and actually the technician did ask me if I had chipped the ECU - which I definitely haven't done. He was thinking that might be the reason why they can't link to the ECU.

 

Thanks, much appreciated Eddie, yes they have checked the replacement pump and it is working - and pipes are connected as they should be - I personally thought there must be something blocking the pipes as the tank had run out completely - even though the fuel gauge was reading a quarter tank when it first packed up. Thinking back now I was cranking over the engine for a looong time, 30 secs at a time, so that can't have done the car any good, if the fuel tank was bone dry. I noticed the fuel tank was bone dry when I removed the original fuel pump to replace it with a known working used oem pump. And the fuel pump housing is supposed to be full of petrol at all times, but it was almost empty.

Reading up here I saw a comment about the immobilizer and the fact that it doesn't like the car battery being repeatedly connected and disconnected for some reason - which I did do over a number of days to keep it from draining - and I'm thinking maybe the immobilizer has jammed shut - as a built in security thing. However, the immobilizer works by cutting the ground to the injectors and coil - so if I'm still getting a spark, then that can't be the culprit -right ??

 

Thanks for that - good point - I did try cycling the key for exactly the reasons you said - but only 3 or 4 times. If the tank was run bone dry, how many times of cycling the key would you reckon it takes to get it right ?
My only thought is that once you start cranking the engine over on the key, you can hear the fuel pump starting again so I am assuming that as long as you are cranking the engine over, the fuel pump is also pumping fuel through.

 

Thanks - good question - but before I replaced the pump I filled the tank up with 20 litres of the good stuff. So its currently got plenty in there.

 

Thanks - awesome idea - never knew that - and I'm sure the technician doesn't know that. When I poured the 20 litres of fuel in, it went in via the pump side. Not sure how many litres you need as a minimum to level both sides of the tank out - but I would have thought 20L was enough. In terms of the fuel line that runs to the filter assembly, I'm pretty sure its hooked up fine, as I disconnected it and tried blowing into it (nothing happened) and then tried sucking on it and got a mouth full of 97 octane.

 

A quick question please guys - I sent the technician the procedure for resetting the ECU - and also reading diagnostic codes from the dashboard display - this should give any fault codes even though they can't connect to the ECU - is that right ??

 

The immobilizer wouldn't stop/block communication with the ECM. I would check all fuses and relays, then the ECM power and ground circuits.

 

Are you sure you turned the top cap on the fuel filter holder when you replaced the filter? I didn't click it completely and had a no start issue similar to you. I took the thing off and on about 20 times before i realized that i hadn't fully turned the cap (letting it click) before putting the rest of it back together. The fuel pump still primed and i heard fuel, but it never made it to the motor! Might be your issue?