Just a brief update. I've now done 170 miles without any funny business from the engine. So far so good, but I'll need to probably do 1000 miles to be sure the problem was in the old ECU. Think I'll take it along for an emissions test, well ahead of the MOT. I believe it is possible to trim the fuel...

The replacement ECU has so far performed well. Apart from local journeys, we took it on a 50 mile round trip yesterday without incident. However, it's still early days. Given that the previous faults occurred very infrequently, I may have to wait a while to know if the old ECU was the problem. I hav...

As I mentioned earlier, the EPC I have for the early R8s and SD3 was called Infomill and came from MG Rover I believe. Copies were certainly around on CD and I got my copy from the founders of the Rover 200/400 Club around 2007/8. It has however become increasingly difficult to use with upgrades to ...

Did a bit more work on this today. As mentioned, the spare ECU I bought last week initially appeared to work with good data readings on RoverMEMS App. However, when I tried driving the car the engine died. The Diagnostic now showed the MAP sitting permanently at 10 kPa, so it had clearly failed afte...

Opened up one of the non-working ECUs. To take out the board, remove the crosshead screws marked S and SL, the SL screws are long ones going through the heatsinks. You don't need to remove the screws in between as these hold the heat sink to the PCB. https://i.ibb.co/Z26JPrT/IMGP0017.jpg The board s...

Thanks, John, that's very helpful. I'll have a go at opening one of the faulty ECUs to see what's involved. As my work was in electronics, fitting a new MAP is not a problem. I wonder if anyone has worked on one of these. There seem to be a lot of crosshead screws on the back of the board. I assume ...

Here's the latest instalment in this saga. I ran the engine up to temperature and connected the RoverMEMS Diagnostic App. Interestingly it showed logged faults from when I lasted tested a while ago. There was a Coolant Temperature Fault and a MAP Fault. Once up to temperature, I got the following re...

I agree, the scaled-back parts list on Rimmers is a bit of a nuisance. They used to list everything including stuff NLA. I've got a couple of CDs of parts. The early ones on a system called Infomill which does the SD3 and R8 up to 1992 and other cars like Montego. Got a copy of this via the Club man...

One other thought. Are all the ignition components reasonably new, particularly the leads and the rotor arm? They could get a bit damp if left unused for periods. I doubt if this is the problem as you would have more trouble getting it started from cold. None of this would explain the excess water v...

White exhaust fumes sometimes indicates a head gasket failure when a small amount of coolant leaks across into a cylinder. It may not contaminate the engine oil, it depends where it's leaking and how much. Is the coolant level full or does it drop at all? Leaving the car standing for a while could a...