Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing 1997 Plus 8 tickover

It would seem that you have an electronic speedometer, one of those 5 wires should be yellow in colour follow the yellow wire back it will either go into the ECU connector or go to the Speed Transducer which will likely be mounted on the bulkhead. Hopefully it is the latter and you can check for tightness and a good earth.

As a quick check that might be worth doing before anything else, do you have a spare coil or could you get a coil they don't cost too much replace and try that? A coil that is failing especially when it heats up can cause erratic engine performance, its a low cost item and worth a try, you just never know.

Thanks. I wondered about a coil. Matt at Lifes did try one I think, but not a bad idea to get a Bosch one anyway. I see RPI sell them.
I’ll try following the wires tomorrow. 👍

Phil, not to distract you too much from your electrical troubleshooting, but have you checked the mechanicals- timing all good, rockers, valves etc? Just a thought, but at idle a small deviation outside tolerances on one part of the valve train might cause your symptoms, whereas at road speed, the rest of the system carries the load and smooths out the running?

Thanks. Good shout, but Im pretty sure mechanicals are good.
Timing was out when Lifes motors serviced but ok now.

I rang RPI Engineering this morning and told him my woes.
He said he has had the same conversation many times with Plus 8, TVR, RV8, Disco and Range Rover owners of the same vintage.
Basically it is an ignition issue. He is going to email me with the details of their cure, which involves the Tornado chip, coil, IAM, and some other things I can’t remember.
So, I am going to leave it till the new year when I can book in for the work, which apparently takes five hours but they like to have the car for a couple of days.
I had a good drive today, and it was great. Stalled a few times but I can live with that now that I can see the way out.

Thank you all for your help, ideas and support.
Looks like we may have a couple of days on the Norfolk Broads in the new year.
Take care, stay safe and have a great Christmas and new year.
Phil

Jolly good; RPI are very good they have always been helpful to me, I have the Tornado Chip, Adjustable Fuel Regulator, Ignition Amplifier, Magnecor Leads and coil which is probably what they are going to fit adjust timing and idle and test.

Thanks. We are booked in, the first week of Feb.
It’s a relief to know that it will be resolved fully, and that is a very common issue.
A few nights in a nice hotel/cottage/boat in Norfolk the week of my wife’s birthday will be a nice change from lockdown.
Fingers crossed for a vaccination in January.

Phil

I have sent you a PM please look out for it before going to RPI

I will get you the tel no. of Mark Adams

Hi Phil,

I had exactly the same with my 2000 +8 about 18 months ago. I had it looked at when it went in for it’s annual service and although it took a bit of investigation, RTCC tracked it down and cured it. Looking back at the service records I can see that it had 2 additional components fitted while it was in:

1 x Temperature Sender
1 x Durite Rover Fuel Pump Relay

I can’t say whether one or both of those contributed to the fix, but neither was expensive. Best of luck getting yours sorted out !

Cheers

Rich

Hello Rich,
It seems I have the same problem on my 2001 Plus 8, Lucas Sagem GEM'S ecu with Tornado chips (Mark Adams). As the knowledge is poor here in France would you please elaborate more, if possible about the two items that have been changed. Thanks and keep safe.
Jacques