Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Part identification help needed

Hi folks,

I've been struggling to identify a couple of parts for a 1996 Plus 4 with the Rover T 16 engine.
The main issue we're investigating is a random RPM drop in the first 10 minutes/miles or so (rpm drops and near stall, rev brngs it back but idle isnt stable)

The two parts are the M.E.M.S and an unknow relay (See image below)


The M.E.M.S ID is clear but it seems as though the part was superseded (per rimmerbros site, by "MKC104082E" which is apparently no longer available)


ATP Electronics seems to have a replacement part "XEMM4080" but it's tagged as "immobilized" and the car currently has no immobilizer so i'm unsure if this would be a straight swap.

The second part (unknown relay) has no identifier other than >PA66 M40< which i can;t seem to reference reliably anywhere


It does have a completely faded TRW sticker but no identifiers visible there.

Any help and guidance would be very much appreciated!

My T16 +4 did the same. It would either idle perfectly, not at all or at 3000 rpm. Changing the ECU solved that. You an get them on flebay with the immobiliser isolated.

This may or may not help but when I had my M16 I experienced a loss of power at 4000 rpm. The engine would then idle for a couple of minutes and then drive normally until the next time. The answer came after a lot of head scratching and a brick on the loud pedal. The cut out was due to the alternator spiking. Replacing the alternator cured the problem . It never happened again. Worth a thought.

Thank you both for the paths forward. The situation is a bit strange as , to me, it seems possibly related to the ECU but not knowing what the relay part is (and it not being sealed as it had electrical tape keeping it closed) has me fearing potential wear to the electricals within it (possible humidity ? short).

any clue what that part actually is? schematics seem to indicate it being fuel or ac (the '96 plus 4 has no AC as far as i know; maybe ventilation)

some more pictures of it for reference

I can´t help much but >PA66 M40< seems only to be the description of the material of the case. So no help in identifying the part

Regards Bernd

Is it a dim dip relay??? Try the lights and see if it trips.

I'm racking my brains because I once had a conversation with a Plus 8 owner who talked about a strange relay......just can't recall what it did!

Cannuck, I doubt that the part you picture is Morgan specific, and as such may be more Rover related than Morgan, perhaps in it`s it`s original design function it carried out a series of switching operations in the Rover environment that may not all be required or even wired into a Morgan.. but I do not know...?

For example in my 85 +8 there is an electrical connector on a pair of wires exiting my sump which I suspect may be connected to a level switch within the sump.. could be temperature.. never took the time to find out... but the connector is blowing in the breeze and connected to nothing in the "Morgan" wiring harness... In a Rover, I suspect it would be connected and operational...?

As for what the unit you pictured might be identified as... different manufacturers use different names... it is an interface between low current digital switching operation and the high current required to switch electrical loads in excess of that which the ECU s internal switching components can directly handle ... often identified as a... high current module...

At a guess, I suspect your fuel pump will be controlled by one of the relays within the module, your ECU looking to have confirmation that the necessary low current inputs from whatever sensors are hard wired on the engine to provide the signal to the ECU that the engine is running and requiring fuel.. The idea being that after an accident the fuel pump will be switched off if the required ECU inputs are no longer sensed. i.e. engine running, thus saving the possibility of pumping fuel out of a leaking fuel pipe should for any reason the ign be left switched on..etc. etc. etc.

Such programming does not end there (much to my frustrations) there are other many other variations possible to control that same fuel pump relay... there could be a security link programmed in which unless the requirements of that system have been met too...the fuel pump relay will be inhibited from operating... In a 911 Porsche if you operate the door handle to enter the vehicle, the fuel pump automatically runs for I think 3 seconds to pre prime the fuel system for a quick start up......Welcome to the world of frustration that digital operation can be when trying to fault find without access to the logic of the control configuration.. where even those electrically and mechanically trained can end up feeling just...err... useless..

Looks like the module was one time factory sealed initially, but someone like you has opened it up looking to see what is inside... (-: You could use some self amalgamating tape to re-seal it, but It does not seem to have suffered much internally since the car was built, so chances are it is not in danger of causing issues any time soon..?

As for what might cause your issues.... Sorry I know not. I particularly chose an era of vehicle construction whereby there was minimal electronic circuitry involved in my choice of Morgan thus I had at least a chance of understanding it`s full operation and the reason for any failures that might occur, increasing my ability to be somewhat self sufficient... the chosen forum I.D. name Luddite, perhaps provides a clue to my thinking....?

The webmaster at GoMoG put a lot of time and effort into gathering information about the electronic fuel injection system as fitted to his Rover engined +8 in a bid to understand it and to improve on his ability to be self reliant (as so many Cannucks seem to wish to be) and made it available to all.. You may find he has investigated your Rover`s system too .. good luck in your search for answers..

If you REALLY want to know what the relays function might be, then if you look at the colours of the wiring on the plugs and refer to the British Standards Institute codes for wiring colours then from the descriptions contained therein of the specific colour codes for use in specified circuits you will then at least know what heavy current circuits are switched by the relays. Of course there will be light wires from the ECU at the location of the high current module providing the light current to the coils, which when so supplied will cause the relay to energise and close the heavy electrical contacts to then provide a supply via the heavy wires on the plugs at the base of the unit in order to energise the fuel pump or whatever high current electrical device might be so connected..

Perhaps not really a "quick" reply, but I hope it helps as opposed to adding confusion...?

Well, generally speaking...…….

Brown is live switching...one may have a trace colour....generally not fused......but who knows
Black earth return

White and green live with ignition circuit

White with red trace...starter switch to starter relay

Yellow.....often fuel injection related

I found this...….https://www.ebay.co.uk/itm/323109442731

Which does look similar from the outside...…...

Good hint Dave W but to be a tad more specific if you beam up and save this link you may open the door to further understanding.... or confusion...? (-:

http://www.dimebank.com/LucasColours.html

When I tried to do that with the bank of relays on my roadster...……all it did was muddy the water even more...………..

I have a Haynes manual but can not copy and paste it to TM Help! I received this from TM about 3 years ago

Quick update:

I reached out to ATP electronics for a replacement 104080 and await their follow-up (a rebuild was requested and we should know if all is good to go in a few days; i hope). Shoutout to Steve at ATP for clarifying my concerns about the immobilizer. It would appear that , since there is no such function on the '96 plus four that the appropriate wiring to get the car to start is already in place and hence the ECU would be a straight swap irrespective of immobiliser function. (Very open to anyone's rebuttal here of course).

Regarding the infamous relay, it remains a tossup since i found the rover 800 relays listing on Rimmerbros and it has only one that looks similar to the one in the Plus Four. it;s listed as YWB100800 ("Relay-Air conditioning"). The hunt continues!

Hi.

The relay is a combined unit for the starter and fuel pump, and it's a pretty standard unit from an MGF/ ZR/ ZS /ZT/ Freelander. Secondhand ones are readily available for about £10.00 or less.
I seem to recall that the other relays contained in the unit are surplus to requirements in the Morgan.

Whether or not it's the cause of your problem is another matter, but I know on my 1999 +4 T16 that I used to own the fuel filter was almost blocked solid. When I replaced it the car ran a lot sweeter, so it might be worth checking before you do too much more investigating, as the fuel might be struggling to get through.

Here's hoping you'll get it sorted soon.

sid, Ten out of ten and a gold star for that info, nice to know that some things do not change at Morgan

Indeed many thanks for the tip Sid.

Quick update from ATP. Alas they were unable to source/build an ECU so back to square 1 on that part. Unfortunately, getting the part over to ATP remains a last resort option I cannot exercise at this time (the car itself being in france and the whole family being over here in Canada until next week.

With that said, I noted in another thread (Immobiliser help) that the following was stated:


Would this mean that the T16 on a plus 4 would take a straight swap from those other model ECUs (I had been focusing exclusively on the MKC104080 and its successors)?

Pending further research to answer the above, i'll be sourcing an MFU and fuel filter .

A.E. Wilcox, Wickwar, Glos. from an earlier thread which proved successful/ Alternatively you might ask Omex in Cheltenham who are very good. My M16 did not have an immobiliser .The ecu was primarily responsible for the fueling map.
I also found a reference to an ECU on a 93 t16 being MKC10034e

Thanks again for all avenues suggested here.

At this stage, I took the plunge and ordered the following:
MFU: YWB10041 (seems to be the only relevant model number i was able to reference. TRW sticker colour matches so there;s at least that)
ecu/MEMS Unit: MKC10115E (Although it clearly isnt a MKC104080 like the one on now, it was directly referenced by jbl as being on a T16 plus four and no immobiliser; the one i found is new in box at a very reasonable price )

Next stop is checking the scrap/salvage lots near cholet for cars with T16 engines to see if any may have an MKC104080

Ordered parts should arrive late this week or early next (both sourced form the UK so Seller response time + Royal Mail to France )

Fingers crossed for some resolution to get things sorted in time for M.C.F's "La Mer Et Les Poissons" in 2 weeks

I have to admit to next to zero hands on knowledge of modern electronic gubbins in vehicles as I kinda lost interest when it appeared on the scene as my chosen forum i.d. suggests.. (-:

A do have some experience in working with digital electronic kit of a wide variety of types and from that it would seem that a Trad Morgan would require very little in the way of specialised inputs and outputs to return it to service if it`s ECU was fried for any reason... ?

I suspect the ECU basic circuitry though appearing very complex will be made up of relatively standard internal input and output devices to connect to a variety of sensors as inputs to create the information necessary to then make decisions relative to controlling the outputs to the injectors...

The programme for output control relative to the inputs it receives, is the decision making part of the ECU and is known as the EPROM, also commonly known as the "CHIP" You may have read of folk re-chipping their cars for more performance... some chips can be fitted to bases in the circuit board to allow them to be unplugged from a socket arrangement and a replacement chip to be plugged in.

Some chips have a fixed programme and others can be re-programmed..?

If you are following this then dependant on what fried the ECU it may just be possible that water got on to part of the circuit within the ECU and damaged it, leaving the chip undamaged, thus a replacement ECU perhaps not programmed exactly as the "original" is just a generic device that would operate as the original if the chip from the original was installed in the replacement unit.... A long shot perhaps...?

If you accept that an ECU can be a generic device with options to be specifically programmed and that the CHIP is the brains behind the operation, then you might be comfortable with the idea that the ECU does not require to be an exact number matching bit of kit to the original or indeed even look like the original box of tricks, though the input and our plugs would ideally be the same... Other than that you are into fitting replacement plugs to your loom.

There would seem to be quite a few manufacturers out there supplying aftermarket ECUs that are suitable for the home mechanic to programme to suit the vehicle in question.... they also supply programming for your lap top which contains the parameters necessary to create a base control strategy and instructions on possible adjustments to alter the fueling solutions... Yeah hard to believe perhaps but with a bit of courage and understanding and the on line help desk it might be possible that you could bring life back to an otherwise totally dead car...?

https://www.amazon.co.uk/Tuning-pro...1&ascsubtag=5d6b8e90eba0c90a984f7b1f

I guess the tricky bit is to know what caused the damage to the original ECU if it was water ingress and you have solved that then great, but if you fit a replacement ECU that might have been damaged as the result of a wiring issue or over voltage then you may fry the replacement too.... OUCH..!

Just passing a slow Sunday Morning in type.. More than happy to be corrected if you think I have got it wrong.. (-:

That's the exact reason i went ahead and ordered the ECU with a different model number than the one fitted (with at least some minor assurance of it having been used on a plus 4 with a T16 engine successfully per the quoted forum post).
I also believe only a partial set of functions is necessary for the morgan use-case (as compared to, say, it being fitted on a rover 800 series).

When it comes to automotive, i would like to consider myself "luddite2" given my preference for not just no electronics but even going as far as preferring carburettors to injection
I can't go too far in naming considering my dayjob is heavily into IT/networking/information security. I just like my motors the old fashion way (Can see it all, can reach it all, can fix it all)

I'll keep you all posted on progress of course.

I have recently converted My Carbed +8 to EFI. It improved the performance, but not that much. Certainly not Cost Effective. I was mainly curious of How Much Improvement I would get from the EFI. Not much I would find out but as it is installed I would like to keep it. It is particularly effective at the higher altitudes that I have been driving lately. ie: The Rocky Mountains are in the 10,000' range. It is an aftermarket unit. Not Rover and it is not designed to reduce emissions. I am often well over 1,000 miles from Home. Not sure what I would do if it failed.

Cannuck, as you are ..err..digitally aware, I`m guessing you opened up the ECU to determine if the chip was mounted in a socket, and distinguish as to whether it was an EPROM or an EEPROM... and if EPROM perhaps you have the kit to copy the programming and flash a new chip... I guess it would be really handy to copy the programming onto some spare chips in the off chance while messing around it gets corrupted either in the original or replacement ECU....


Hey Button, saw your piece in Format the Californian Morgan club Magazine, I am fortunate to get sent a copy each month.... Your looking good, better than I do... (-:

EFI is so much more efficient though best to have fuel filtration to match as filtering for carbs does not need to be so fussy..But then I guess you upgraded the filters as part of your modification process... I note you have concerns as to the repair processes should you have an EFI fault while far from home, I suspect a good quality basic system will be very robust. of course being digital it can be possible to to programme all sorts of bells and whistles to add all sorts of complexity if the unit has enough capability and most do.. but perhaps best to keep it simple..?

A friend bought an old V8 Lexus with all the bells and whistles the intention being to use the engine in his Ford F100 p/u truck. He worked his way through the loom cutting a wire at a time and then firing up the engine after every cut to be sure he had not cut out anything critical to the basic operation, once he had cut his way through the majority of the loom and was happy he could install the tidied up remnants in the F100, he took the key out... next time he tried to start the engine...NOTHING DOING... the action of removing the key and replacing it had required a signal that was no longer in circuit.... Yeah carbs, points and a distributor are pretty simple to understand by comparison...

"A friend bought an old V8 Lexus with all the bells and whistles the intention being to use the engine in his Ford F100 p/u truck. He worked his way through the loom cutting a wire at a time and then firing up the engine after every cut to be sure he had not cut out anything critical to the basic operation, once he had cut his way through the majority of the loom and was happy he could install the tidied up remnants in the F100, he took the key out... next time he tried to start the engine...NOTHING DOING... the action of removing the key and replacing it had required a signal that was no longer in circuit.... Yeah carbs, points and a distributor are pretty simple to understand by comparison..."

While a guest of Tcherek and Bill Fink I asked Bill to sell Me the latest EFI that He had that had been removed in the days of Propane. It was a 13CU 3.9 Rover unit. After carting this heavy blob a 1,000 miles home I have it on my dining room table with the harness all stretched out and with the ECU that came with it. Lorne Goldman assured Me that the ECU was for a 13CU system. Interestingly there are no Oxygen Sensors used on this unit. I understand that this particular unit was just for North America to satisfy California Law. My plan is to have the Throttle Body EFI that is now on the +8 tested by a Rolling Road. I need a starting point. Next Winter, when I am bored, I will exchange the Aftermarket unit for the Rover 13CU MultiPort unit and hopefully get it running. Then take the +8 for another test on the Rolling Road and compare the results of each test. I know, I know but My curiosity is controlling.

Button, you are nothing if not adventurous...(-: With EFI, I would be happy just to have an operational system rather than fiddle with it, that stuff can frustrate me, to the extent I feel foolish. From a very dull memory the airflow sensing device "flapper" having moving parts would seem to be a potential source of issues in time having a mechanical flap attached to a variable resistance and wiper involved in its construction, the flapper may be a tad larger and more complex than some of the later hot wire devices used to sense air flow.

I helped a pal resolve some issues with his Rover V8 engined TVR and the air flow measuring device was perhaps 1/2" in diameter and 1 1/2" long tube, presented to the airflow through a hole bored in an alloy tube.. certainly nothing sophisticated about that, but it worked just fine, the ECU was nothing like the size of the Rover units I have seen, and much more compact... Some of that early Rover kit is stone age by comparison with the later digital kit.... If I remember during the GoMoG webmasters search for answers he cut open the loom and found a set of resistors, one for each injector hidden within...? I suspect there will be a modern system that is perhaps far more compact, reliable, efficient and adjustable from sport to economy mode with the push of a button, and programmable from a cell phone...? But I ain`t selling that as any kind of ideal, my inclination were I in the US might be inclined towards a down-draught Weber.... Although given that you fly in thin air altitudes at times... hmm..???

I suspect the real value of the system you got from Bill may be as spares for folk with flapper systems who are in need of replacement parts, the flapper it`s self being the most suspect point of failure perhaps..? But then perhaps the challenge in increasing your understanding of EFI systems is that which drives you...? (-:

If seeking information in book format on vehicle electrics including early EFI I use the Bosch publication Automotive Electric/Electronic Systems. ISBN 1 85226 021 1 I have no doubt they may have updated it somewhat from the time when I bought it..

I think the EFI thing came into being to cut down on pollution by producing more accurate fuelling creating what were then known as lean burn engines.... Thinking in a simple fashion as is ever my way, lean burn would seem to equate to what I in carburettor parlance might think was weak mixture ...? Weak mixture in times past would cause holes to be burned on piston crowns so plenty of extra HEAT there...? Following a similar line of thought, that EFI engines might run hotter, then it seems logical (?) that such a change in engine design would have more dependence on cooling..? I remember on a run through traffic with a more modern +8 following close behind me, that I could hear his fan running constantly, whereas mine did not run for anything like the same length of time... More load on the battery and alternator etc.etc.etc..hmmm..?

In conclusion having read your submission in Format re overheating, perhaps EFI may cause issues re engine temp when introduced to an engine that may not be designed to operate with a lean burning fuelling system, that typed, I suspect the lean burn technology may have come in with the 3.9 unit...? Whereas I think the early flapper systems were fitted to 3.5...? Whether the lean burn engines were greatly modified in terms of materials used in their construction to cope with higher temperatures, or water galleries increased in size or more efficient water pumps or increases in efficiency of the radiators... I know not.

Just thinking in type as ever and claiming ZERO expertise.. and as ever more than happy to be corrected.

Hi there, jbk's comment about the potential of an alternative with Pt No MKC10034e & 10115e is very interesting and useful piece of info. I had my MKC104080 (T16 Morgan +4 1998) rebuilt by ATC Drivetrain of Cannock in June 2024 it had an ignition and fuel pump output issue, I had to return it to get it set for 'Free running' (by passing the immobiliser). Like most Morgans of any age if you do have a Lucas 5AS immobiliser and your key fob is US or not even in existence then you probably don't give the immobiliser any thought as it will set to 'run'. However my fob was long gone and I had to rely on the ECU being set to accept that. I have since had a MAP sensor issue (the sensor is inside the ECU and is not user serviceable), the car intermittently would either fail to start or start but not run well at idle and jus die. I sent it back under lifetime warranty and they repaired it and it wouldn't run at all, (it had run previously most of the time), so sent it back and I'm waiting for the next step, will it work...........? I don't know yet, I'll repost and let you know.

I keep a constant search for a 104080 but the info from jbk has set me thinking about (non immobiliser) 10030e / 10115e

Really interested in if the MKC10115e functions correctly and if it is OK without the immobiliser, if it did then this really may be the answer to a replacement for the 104080, pray to god!
please post your results good or bad

Hi the relay box is the MFU (multifunction relay unit) The Pt No is YWB100710, it controls the Lambda, ignition, starter solenoid and fuel pump functions (via instruction from the ECU)
With regards to the bad idling and stalling mine did the same and it was the MAP sensor, this is part of the ECU and is not a user serviceable part. The MAP sensor controls the air fuel ratio and the vacuum pipe that connects to the ECU / inlet manifold is crucial, so make sure this pipe is not split or rotten or lose, its a cheap fix and will mislead your ECU like crazy.
If you need the pin out identification and diagram of the internals and functions, please let me know. I'd be happy to fwd the doc I can be contacted at stephen60plus4@gmail.com.