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The M.E.M.S ID is clear but it seems as though the part was superseded (per rimmerbros site, by "MKC104082E" which is apparently no longer available)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