19 replies to this topic

[Mart!]

we're trying to bench start a Auto SPi engine (NOS crate engine) that was purchased without a loom a long time ago. we managed to find a loom and matching ECU and we're now stuck where the engine turns and the injector only works for about 1 second, not long enough to actually start the engine. wondering if the 101361 needs to be matched to an alarm/immobilizator/keyfob?

 

located in Quebec, Canada, no access to Rover dealership with diagnostic material...

thanks a lot!

 

Martin

 

 

[FlyingScot]

MNE 101361 is SPi auto, and as far as I can tell from my notes, it's Japanese J spec which probably means no immobiliser.
I am guessing if you have the matching loom you could check for the immobiliser connector which is grey and 26 pins assuming both came from the same car?

FS

[FlyingScot]

Also check the crank sensor

FS

[Mart!]

thanks! it's a crate engine, it was never installed in a car... the loom was bought new from a UK suplier and ECU is used, so nothing comes from the same car. seems there isnt any gray 26 pin plug so that's probably a good thing, but doesnt explain why it wont start

[FlyingScot]

On turning key to position II does the fuel pump prime? (Can you hear it running for about 5 secs?)
Is the crank sensor correctly connected? (On a similiar motor one of my friends had plugged the connector into another component)
Is the MFU (relay pack) the correct one for the car and does the fuel pump relay energising for priming and then staying energised or dropping out?
Is the inhibit switch for the auto made (the connection to stop you starting it in anything but park ? I assumed this worked on the starter but on later models I am not certain.

FS

Edited by FlyingScot, 17 May 2015 - 06:00 AM.

[Mart!]

Yes the fuel pump primes up for about 5 secs. The crank sensor is correctly connected.
We have a MFU but not sure if its the correct one, what is the right part number?
For the inhibit switch, we bypassed it by connecting the 2 wires together.
the engine runs fine if we spray gas in the intake...
Thank you for the information!

[FlyingScot]

Okay sounding better, check the MFU see the thread here http://www.theminifo...-functionality/
Check the wiring colours should be the model number I have quoted for your SPi.

FS

[Mart!]

thanks - looks like we have the proper yellow tag MFU. the injector works for just under one second, after that we only get a very faint current pulse. we tried sending clean 12v straight to the injector (think morse code tapping) while turning the ignition on and we managed to start the engine for about 5 seconds (before flooding it) but it proved that the injector works. could a bad ground have damaged the ECU? it seems like something needs to cool down after we attempt to start it because the injector will not work twice in a row, it needs like 30 seconds off. couldnt hear any "click" except for one coming from the MFU, maybe 10sec after switching the ignition off which doesnt seem related (trying to start after that click doesnt work, still needs about 20sec)...

 

i hope my explanation make sense!!

thanks again!

Martin

[FlyingScot]

I would say from what you have described that either you have a wiring fault or a possible ECU driver output fault.
Double check the earths and power supplies to the MEMS ECU first. If you don't have a wiring diagram PM me with your email address and I'll email you one.

FS

[Mart!]

ok, so we double checked the entire wiring and had the ECU checked and everything appears to be as it should. we're using light blue haynes diagram, maybe that's not the best one to go from? again, the engine is on a bench with only the engine-relevant electricals hooked up. is there anything that would cause the injector to stop after 1 second? for instance, there's no airbag hooked up, would the ECU or whatever else read that as the airbag being deployed therefor preventing the engine to start?

 

i'll take you up on that diagram offer, maybe there's some differences that will show up. pls send here: mart [at] cheese-factory [dot] com

 

thanks again!

Martin

[dbcool20]

On some recent cars the ECU indeed detects when an airbag has been deployed, and cuts the fuel supply i.e. in the case of an accident. I can't say for sure and correct me if I am wrong but i doubt the MEMS ECU has this function. On my non airbag SPI this is done by the Inertia cutout switch. maybe this inertia switch is your problem? 

[Mart!]

yeah but the inertia switch would cut the fuel pump, not the injector no?

[xrocketengineer]

The MNE101361, like FlyingScot mentioned, is for the Japanese Auto SPI. However, is for the latest version with no distributor (MPI type coil pack). Iif that is correctly matched then the wiring diagram can be found on page 18 of the following link below:

 

http://www.theminifo...attach_id=68240

 

An explanation of how the MEMS system works including the Japanese version (97 on) can be found on page 33 of the link below:

 

http://www.theminifo...attach_id=68242

[dbcool20]

right the inertia switch cuts the fuel pump. not the injector

Edited by dbcool20, 29 May 2015 - 09:34 PM.

[tmsmini]

I thought somewhere in that document it was mentioned that after the fuel pump is energized initially, a signal from the crankshaft sensor was required to keep the fuel pump relay energized. I cannot seem to find that reference at the moment, but it should be in this section:

FUEL PUMP OPERATION

One side of the fuel pump relay coil receives battery voltage from fuse A4 in the

passenger compartment fuse box on a W wire provided the starter switch is in

position II. The other side of the relay coil receives an earth on a BP wire from

the MEMS control unit provided the correct operating conditions exist, (see

Engine Management System) causing the relay to energise.

The energised relay switches battery voltage from link 4 in the engine

compartment fuse box on an N wire, via fuse C7 in the passenger compartment

fuse box to the inertia fuel shutoff switch on an NS wire. Provided the inertia fuel

shutoff switch remains closed, battery voltage is fed on a WP wire to the fuel

pump. Since the pump has a permanent earth on a B wire it will commence

operation.

 

 

Possible issue for an automatic:

Inhibitor switch

The switch fitted to the gearbox inhibits operation of the starter motor unless the

selector lever is in position P or N.

With the selector lever in position P or N the inhibitor switch will provide an earth

path for the starter relay on a BLG wire which will allow the engine to be started.

If the selector lever is in any other position than P or N, the inhibitor switch will

not provide an earth path, so preventing the vehicle starting.

The inhibitor switch also provides the ECM with an input so that idle speed is

automatically adjusted when a drive position is selected.