Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Rover M16 Plus 4 1990

Hi,
Some technical information if someone can help please.
1. What should be the ohms resistance in the lead between the coil and distributor for the Rover M16 motor? (the Rover car with that motor was the 820 with Lucas multi point fuel injection)
2. Also the ECU has a 3 pin diagnostic plug but it is about 1 year before a reader could be used (it is a 14CU unit). From what little I can find with extensive research it must have enabled a number of flashes of some lights on the dash from which you can work out a fault code. Appreciate if anyone with experience of this motor can help me out here? Would be great to know how to link into the diagnostic plug to get some codes and also the list of the faults it shows.
Thanks, Col

Col

I am a mere amateur on the diagnostics side compared to many here, but I have a couple of pointers for you.

As you have probably already surmised this was prior to the industry OBDII diagnostics standard. However there is a port on the ECU that can be interrogated with RoverCom software . Now where you would find someone with that kind of gear nowadays , especially in Oz, is anybody's guess.

I would start with old school Rover dealers , they may even have a set going spare as they would rarely have call for them nowadays. IF you have a Morgan Dealer which doesn't involve travelling down to NSW/VIC then they used to carry it. There may also be other Morgan owners in OZ who have their own personal kit, pu a call for help out on the MSCA website.

Thanks for your reply MOG615 and apology for the delay in adding to this post. (Haven't been able to track down any old Rover dealers in Oz yet but apparently there are some in NZ if I can find out about them as the Rover 820 car was exported there).

Since my post I have had the help of my brother who is very handy with a multimeter and tracing a wiring diagram. We have gone through most of the wiring between the ECU's and the sensors and done diagnostic testing as much as we can with the multimeter. It seems that most of the readings for the Rover M16 are very similar (if not identical) to that of the Plus 8's with the Rover V8 and 14CU ECU's of the era. The sensors we have replaced with new are both fuel and coolant temperature sensors, crankshaft sensor, throttle potentiometer, a new ignition ECU, a refurbished fuel ECU, new coil and spark plugs. The readings we are getting are all within specifications including fuel line pressure readings and fuel flow. We have checked vacuum hoses and can't find anything visibly amiss.

We think we may have a faulty Mass Airflow sensor (MAF). We have been able to start the car and get it to idle by adjusting the idle mixture screw as a base setting. Can even rev the motor, sometimes smoothly, other times with a lot of hiccups, and have had it for a few short drives. Sometimes it will run good as gold then it will run rough. Took for a run of 30km and it would miss a bit then pick up again; on the return journey it ran like a dream. 2 hours later - no start!! We have used a CO2 analyser in the exhaust in setting the base idle and the mixture screw. Seems to start better first up in the morning when cold, but after running for a while and warmed up will start if turned off and immediately restarted. Leave it for an hour or so and it either won't start or is reluctant?? Very frustrating.

Literature seems to indicate that the car should run without the MAF connected and the computer would go to limp mode at revs, however I don't seem to be able to get the car to run without it connected??

The MAF on the M16 is the Lucas/Hitachi 4AM unit. The V8 Rovers of the same era used a 3AM and a 5AM unit which are apparently interchangeable. (Also noted is that Saab used that same numbered Lucas unit for their 4 cylinder motors). Does anyone know whether I could use one of the 3AM or 5AM units (either from the V8 Rover or the 4cyl Saab) instead of the 4AM unit?

Has anyone adapted some other MAF in place of a Lucas unit that will send the right signal to the ECU?
Any help, much appreciated. (I'm currently making enquiries whether I could get the existing MAF tested & refurbished but would most likely need to send it to UK if the service is available).
Col.

Have you changed the coil ?

Hi
An update on the M16.
Finally ...... back on the road after almost 16 months ...... so o o o o good!!
While ordering a throttle body adapter, decided to get a new distributor cap, rotor arm and plug lead set as well while at it. Thank you Rimmer Bros. (The T16 parts as listed and stocked by them also fit the M16 luckily).
Anyway, just last week put them in and it fired up first cranking, and again and again. Idling and revving fine.
Took it for a run of about 25 miles and went well except for one quirk??
Yesterday, a longer run, of about 65 miles with a couple of stops half way. A colder morning and took about 3-4 crankings for it to fire up but restarted first up on following starts when warm.

The QUIRK ...... when doing a sharp right turn and accelerating, there is a miss/splutter momentarily until I back off slightly. Noticed it when doing a right turn at an intersection or a sharp right hand bend and accelerating out of the corner. At first the fuel tank level was showing as a bit above empty so thought maybe getting air lock but added additional 30 ltrs and has made no difference. (it is EFI and the miss occurs pretty much immediately in the turn).
Accelerating on the straight, uphill or left hand corners there is no problem or hesitation. Baffling to say the least!! Today on a run of about 20 miles I noticed it continues to splutter if I keep my foot down but fine once I back off the throttle. Seemed to be OK on a long right sweeper. I have checked to see if any wires were being fouled by the steering when turning to the right but haven't been able to identify anything yet.

Anyone heard of such an issue? Suggestions?
Thanks.
Col

Check the vacuum hose from the manifold to the ecu. It can perish