Yes this one is Jap spec so no demobilizer it's just plug and play as soon as i find the right one, the downside being the UK ones seem to be in more abundance.

Thanks guys - the crankshaft position sensor is a good idea - I'll do that.

As for Bad ECU, I've been there.  My ECU went bad shortly after I bought my car (like on the drive home) and I started losing functions a few at a time.  Big Al loaned me an ECU at the time to prove that was the problem and then I ended up buying one off EBay in the U.K. that did not have a demobilizer code.  It was a huge pain.  If I had to do it over again, I think I would consider just switching back to carbs....

No Proof- but Timing advance changing -- I would replace ( throw a ) Crankshaft position sensor on it.

Under the starter- reads the flywheel. RPM's

Ive seen them DIE- or give strange signals.  make sure wires are clean and no corrision in the plug too,

//www.minimania.com/part/ADU7340/Fuel-Injection-Crank-Sensor-Spi-And-Mpi-Mini-Cooper--S

I just worked on one with codes showing for the usual stuff running good one day then crap the next and it ended up being the ecu itself (no code), still trying to locate one.

Thanks for the advice.  I'll hold off ordering a new pump for now and do some more investigation.  Unfortunately, the issue does not repeat regularly (sometimes it takes a few days of driving) so a fuel pressure gauge that can't be read while driving isn't much help.  Maybe I'll borrow a transducer from work and add a 0-5 VDC pressure transducer run to a multimeter so I can see the pressure in the car....

Your comment about idle air control valve is a possibility if that can make the car cut out completely.  (It typically just goes from running flat out to stalled in a second).   I've had idle issues for about a year.  I've changed the O2 sensor and the problem goes away for a short time and then comes back.  I have a diagnostic tool and the engine reports no codes.  If I use the diagnostic unit while idling, I see that the timing advance is constantly changing.  i suspect I have a bad sensor causing the engine to alter the advance but I can't figure out which one since they all report as fine on the diagnostic unit.

I would highly doubt there is a external pump that will pull thru a Solid state in tank pump in position.Dont complicate matters with 2 pumps and such - Need to fix the issue.

WHen SPI = MPI satrt having fuel pump probelms this usally blows the fuel pump fuse = as i JUST did this repair on an SPI .

Walbro 190 LPH pump is a Minor modification - nearly direct install pump.

(send me you' pump unit - ill install it to the assembly for aplug and play mod)

But otherwise its simple.   https://goo.gl/photos/MtoD61uFY4TN4WuT8

//www.amazon.com/Walbro-GSS278-Fuel-Pump/dp/B000EDCO5M/ref=sr_1_2?ie=UTF8&qid=1437497484&sr=8-2&keywords=walbro+190&pebp=1437497516238&perid=0MXCSV106PXQRVETV7XR

I would test your fuel pressure properly with a 24$ fuel pressure test kit to verify constant pressure flows.  rule out the pump or not.

Then its a problem of electrical supply to the fuel pump.

//www.amazon.com/ABN-Fuel-Injection-Pressure-Test/dp/B00QL8O3G2/ref=sr_1_6?ie=UTF8&qid=1437497750&sr=8-6&keywords=fuel+pressure+test+kit&pebp=1437497758615&perid=0JAT6AVQVWTWXNR30N8G

As mentioned- Hot wire the fuel pump on and the  Car should run no problems if the pump is OK

Two Yellow relays on Fire wall control Fuel pump too.

Surging and stumbling-- Injector? or Air Valve or idle control valve would be more my investigation.

I believe the pump was actually Bosch but would have to verify that.

People have adapted warlbro pumps.

$200 for the pump only seems steep, but they were asking $400 for the whole assembly at one time.

//www.minimania.com/part/WFX100811/Fuel-Pump-Only-For-Wfx100810-Fuel-Injected-Spi--No-Tank-Fittings

It may be in one of the old threads here. I think you had to take the new pump off the piping/insert it comes with and install it on your old piping. Make sure the fuel pump is the problem first, they usually work or don't and is probably not the cause of your rough running. Don't think it strange with GM and Rover as they were in bed with Honda in the 90's also and a few of their electrical parts made their way onto Mini's. Rover's and BL's and in fact a lot of the British car industry of the 60's> mentality over the years was if it has already been produced by someone else we can get it out of the parts bin and make it work in our application, btw the fuel filter is the same one used by Land Rover and possibly GM who knows LOL.

Anyone know the GM part number?  That seems strange as Mini was owned by Rover at that time but if it works, I'll go with it.  Given that the car is 20+ years old, it is probably time to replace fuel pump and ignition coil for piece of mind.  i hate get stranded and having to be towed.

You can find them cheaper than that i believe it is a GM part. Make sure it is not the fuel pump relay going bad by connecting the tank with a direct feed from the positive side of the battery, don't forget to disconnect it when you turn the engine off.

You may want to check all the vacuum lines from the ecu to the air filter especially the elbow ends as they deterioate and the car runs lean then goes into rich mode to overcome the leaks. Make sure the fuel trap is clean too if that becomes clogged with fuel the computer does not get a signal and the car will run rough.

If you find one or more of these problems you need to re set the computer/system with the Sikes Pickavant scanner as the codes stay stored, disconnecting the battery will not clear them.

My injection SPI mini is randomly stalling out at times and surging.  If I get out, and mess with the wires and hoses going to the tank, it starts up and runs good for a while.  Since it's not consistent, it is difficult to diagnose and I'm ready to start throwing parts at it to make sure it is robust.  I was planning to replace the fuel pump module in the tank (since it never has been) but I now see that is more than $200!  There is also a solid state fuel pump that can be installed inline and claims it will pull through the fuel pump in the tank.  Is that a better options for <$100?  What do people think?