Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Plus 4 Rover M16 ECU

Hi
I am needing some advice from someone who knows the electronic workings of the Rover ECU's - 14CU
My car is a 1990 Plus 4 however the M16 engine will be an '89 model. Apparently the 14CU unit was only used for that one year (the unit is mounted near the glove box under the dash) and there is a separate Ignition Control Unit which is mounted on the firewall in the engine bay. This motor has no catalysts fitted and is just 1 year prior to the fitting of the OBD diagnostic plugs.
All the information I can access on the internet deals mostly with the 14CUX ECU's and all as fitted to the V8 models. not the Plus 4's.
Questions?
1. Can I test with a multimeter whether the ECU is working correctly?
2. Would it be possible to exchange a 14CUX ECU (maybe from an early Range Rover/Discovery) for the 14CU unit or are they totally incompatible? I'm assuming the programming will be different being from a V8?
3. If incompatible, can units/chips be sourced that will work for the 4 cylinder Rovers ECU's?
4. The wiring diagram shows a diagnostic socket (and I have found this near the coil in the engine bay). It is a 3 pin horizontal plastic socket. I'm assuming Rover dealers from the era must have had something to plug into this and get some sort of feedback from the ECU. Has anyone had experience with using this?
It would be great if someone can help. Have fuel, spark and compression but something not talking to something else and can't get the engine to start!! Frustrating!!
Thanks.
Col.

Immobiliser ?

I must admit that I did not know the 14CU unit was fitted for such a short time.

THE expert on these systems , (he mainly deals with the Rover V8 applications but the technology will be similar) is Mark Adams at Tornado Systems. I think he is based near Shrewsbury

www.tornadosystems.com

Inertia switch accidentally tripped, cutting power to the petrol pump? The diagnostic socket you describe sounds like the same as in a +8. Whether the RoverGauge software would work I don't know. It would be a case of suck it and see. How did the car become afflicted?

Fortunately no immobiliser fitted to M16 or the early T16 which make life much simpler.

Thanks for replies so far - I will email Tornado to see if they can assist but still welcome answers to the ECU questions above.
By immobiliser - do you mean inertia switch? My Plus 4 doesn't have one.
As to how it became afflicted - - it was sudden. After a timing belt issue and subsequent valve replacement (see an earlier thread) the engine started as normal, warmed up and took for a short run when it just died after coming back to idle.
It will crank OK, and fuel pumping through to fuel rail - (volume seems right, not sure of pressure?) Timing light seems to be flashing at appropriate time. Compression is even in the 4 cylinders.
Another query - - would the ECU retain the fault codes and create a starting issue? If so, what is the procedure to clear the ECU memory of the faults?
Thanks again.

By immobiliser, I mean the one fitted in later ECUs that require a Blipper in order to start.

early ECUs as I understand were simple fuel control devices,(Mems) fault readers for early Rover engines are few and far between, never found one to buy.

When starting running / tickover issues arise on the T16 I simply reset the ECU by turning off the main red switch and turning on again
equivalent of turning a computer off at the wall.

Bit simple but worth a try?

Hi BB, yes, the 14CUX will retain fault codes but I'm not sure that would cause a starting issue. If the fault persists, that would cause an issue and the fault code would just recurr. If you want to wipe the fault codes just turn off the power to the ECU. If your car has a cut-off switch with a red key like the +8 that will do it.

As this happened just after a timing belt replacement and valve issue, I'd be tempted to check that nothing has slipped in that department. Check the valve timings.

Something could have been left loose or maybe under tensioned to allow it to run for a while but slipped when the engine went back to idle.

If I have a problem just after I've finished a job, I always re-check my work if it's in a relevant area.

If you think this could be an outside possibility, I wouldn't keep cranking it until you are certain the valve timing hasn't shifted.