Well here's how the mems injection sytem works. There are a few things that happen when you go to start the car. 1: First misconception: The injector does not pulse fuel as you are cranking the starter motor! If you have an immobiliser, first key fob sends signal to the ecu which sends power to the MFU which contains a relay that powers up the fuel pump. If you have no immobiliser skip this step. When you turn key to on position, the MFU powers up the fuel pump for only about 3 seconds. Triggers an injector spray Until the car actually starts thats the only time the injector fires. If you shut the ignition off, remove the key then repeat above the fuel pump will power up again and the injector will fire. On an SPI or MPI SPI hybrid there is a brown wire with an inline fuse directly behind the air cleaner on the bulkhead. This fuse holder is problematic and typically overheats and melts. I've found this issue on many of these cars. This causes the car to start then stall shortly afterwards. Cure: Replace with an inline fuse holder and you're good to go. If you have someone spray a little carb spray, (not starting fluid it's too volatile) use carb spray down the throat of the throttle body you can confirm its a fuel issue. 2. Fuel pump. USE low grade ethanol fuel and you can be sure the pump is shot. To check pump follow number 1 procedure above. When the key is turned on you should hear the pump in the tank whirr for a few seconds. then shut off. AGAIN it does not run continuosly on start up!! I've seen the pumps work on start up then as they run they heat up, slow down and eventually stop. You let the car sit then it will start and repeat above senario! 3.MFU this is the large black relay box located on the top of the brake booster bracket! this relay does fail and I have disassembled them and repaired broken solder connections on the fuel pump relay to the board inside. THis also causes an intermittent shut down of the car. Relay connection doesn't totally fain and causes the above shut down symptoms. To see if this relay is sending a signal to the fuel pump you need 2 people. One with a test light inserted into the power wire on the puel pump and another to cycle the key. AGAIN you must remove the key from the switch every time or the pump relay will only cycle once! Follow instructions under number 1 above! If the test light lights up your fuel pump s shot! I have also encountered the same symptoms as mentioned. Car will run for a minute then shut off. More indicative of a bad fuel pump. AGAIN if you use regular ethanol fuel these pumps are not designed for it! USE non ethanol if available or premium 93 or 94 which contains way less ethanol typically. SO there is the basic run down on how to check and isolate a fuel problem from a computer or sensor issue! Any other suggestions are a waste of your time and money. I've rarely seen an ecu bad or a stepper motor failure. Start with the spray of CARB SPRAY into throttle body as mentioned above. IF the car starts and continues to run with a short burst of spray while its running you have a fuel issue not an ignition issue! If you want to learn more Go online and google rover mini MEMS and you should find a link online to the complete manual and function of the system. GOOD luck! Keep in mind these are the bare basics of the function of the system, just enough to do a abasic trouble shooting of the system. Here are the links to mems functions and trouble shooting: https://www.ryansautomotive.ie/wp-content/uploads/2015/08/Instructions-RoverLandrover-MEMS-emulator.pdf

https://www.uscars.biz/uscars/mini-documents/Rave_CD_wmxn990e.pdf

This third link I'm having an issue with if it doesn't work copy and paste it in google search bar. Site is in france and might require you changing your security settings to view the MEMS manual posted there. 

https://britishminicorp.chez-alice.fr/RoverMEMS.pdf

Hi squeekys

i also have a 1.3spi facing similar problem

mine is the steppe-motor problem, you can open it and apply grease to it so that it can move more freely,
otherwise the friction will burn the ecu stepper-motor control part in ecu..

you can also use the mems fault code reader with the usb cable to read the stepper-motor steps while driving or testing

to see the missing steps cause by friction/stepper-motor overloading.

https://memsfcr.co.uk/

 

I would think it is better to use conductive grease on electrical contacts than di-electric grease.

Squeekys, Your point about Randomness makes me remember that maybe you could check, wire brush, and apply an extremely light coating of dielectric paste to all of the Grounds for subframe to body, battery to body, and even those within the FI system. I know that it is cheeky to introduce grounds so late in the discussion, but maybe that could be part of it? Please consider using - sparingly - only the CRC Electrical contact cleaner with the battery unplugged from the car, and inspect every pin carefully on the mega connector harness plug to the ECU. Some Fords have had a sort of "Crazy" problem with OBD2 codes being very random and even incorrect reporting due to corrosion. More common in the corrosion states of course. So, Maybe worth a try? Since it has been a few days hopefully problem solved? Mark

Received a new MNE101361 computer today and plugged it in and nothing changed. Went back to the old computer, pushed it back in the shop and tried starting it a few times over 30 mins or so and it started up and stayed running. Drove it around the block a couple times without issue. Shut it off and turned it back on, no issue..

I hate it when random problems fix themselves..

Thanks for the response, Mark. 

it is a 1998 JDM Auto that has the mashup MPi/SPi.

I’ve read that the keys and computer on that model isn’t coded so you can swap them out more easily but maybe I’m wrong?

I pulled the relay pack apart and it looks great inside and I can visually see the relays working and the power is making it through the pins.                                                                                    

I'm not certain, but is your 98 a JDM model where the FI is a blend of R.O.W. Mpi and SPi? ( does it have - or did it have, AC? ) The ECU's are known to be easily repaired in the UK, and they can even prepare you new key fobs / remove the immobilizer problem, to go with your repairs. Google your MNE 100xxxx number and then some sort of SPi / MPi language and you'll find them If you have a MNE101150, (more of a R.O.W. SPi unit), I have one for sale on Ebay. I suspect you have a later ECU. One other thought is that your "Relay Pack" performance may be intermittent due to bad internal connections / cold solder joints / severe corrosion. The same sort of problems can exist in your ECU.

I'm glad to discuss, let me know if I can help. Best, Mark

I ran through the process on resetting the stepper motor and it seems to be functioning properly.

I have a new MNE101361 computer showing up in a couple days

Comment from Bill Cox:
"It is in the ECU unit..  and their is also idle motor in throttle body that can cause this.. best at this point to just convert to Carb..  when a SPI mini starts this.. no way to fix for good.. later bc"

Having a problem with my 1998 Japan Spec SPi.

 

Leading up to the problem, the car would occassionally die while driving. I'd pull over, it would start up again and I would keep going. This problem has now gotten much worse and it wont stay running at all.

 

If the car has been left overnight, it will start and run for 1-2 minutes.

 

If the car has been ran (slightly warmed up), it will start for a few seconds and then shut off. It will only start if the key has been turned off for ~10 seconds and the relay shuts off. If the car dies and you dont turn the key off, and try to crank the engine, it will turn over but wont start at all. Turn the key off for enough time for the relay pack to shut off and it will start back up for a few seconds before shutting off again.

 

The injector DOES NOT spray when when cranking after it has died, only if trying after turning key off for ~10 seconds. Injector stops spraying when the car dies.

 

The car is only getting fuel on crank, and only if the relay pack has been allowed enough time to reset.

• Relay pack is functioning as it should.
• Fuel pump primes and runs.
• Fuel pump relay shuts off a few seconds AFTER the car dies.
• The car does not cough or try to run, it acts as if someone turns the key off, just instantly shuts off.
• Power is constant across all the fuses that should have power when they are suppose to get power.
• Getting spark during crank and no start condition.

• Tried bypassing fuel inertia switch, no change.
• Tried replacing fuel filter, no change.
• Tried replacing crankshaft position sensor, no change.

 

It seems like the computer is telling the injector to stop spraying. My understanding is that the computer tells the injector whento spray absed on crankshaft position sensor. Does it rely on anything else?