[ROVERNET - UK] SD1 Problem

[Glen Wilson]

Michael,

David beat me to the punch, but I was also going to suggest the solder 
connections in the ECU and the ones on the power transistors in 
particular. These big metal transistors get hot, and as they heat up and 
cool down repeatedly over the years, the solder connections actually 
crack. Sometimes you can see the pins are sort of floating in the 
solder. The result is an intermittent condition where there is a poor or 
high resistance connection that changes as the board warms up and the 
metals either get tighter or looser as they expand unevenly.

The symptoms may vary somewhat. I had one ECU that idled beautifully, 
but ran poorly with any throttle applied. Another one missed at higher 
rpms. I have seen symptoms like this disappear after simply reheating 
(remelting) the 25-year-old joints. There may be a number of other 
explanations for your problem, but you ought to check the ECU and reheat 
the joints anyway, if it hasn't been done sometime in the last few years.

Also, if there is a good ECU in your parts car, it's pretty simple to 
just swap that in to see if your symptoms change or disappear. Just bear 
in mind that the ECU you swap in may have similar symptoms if it has 
never been gone through. I guess you know that the ECU is in the 
passenger footwell.

Give me a call, if I can help.

Glen



Lewis, Joseph (Michael) wrote:
> Hello fellow Rover enthusiasts -- 
> I have a problem and I hope someone can help me solve it. MY federal SD1
> with fuel injection recently started running very rough. It feels like I
> lose a cylinder or a bad firing miss. It doesn't occur during cold
> starts but within 3-4 minutes it occurs. The loss of power is dramatic
> needless to say. 
>
> I changed the wires, plugs, cap and rotor but this didn't solve it. 
>
> Any ideas, guesses or experiences with something like this? Thanks for
> any help. 
>
> J. Michael Lewis
> Gambrills MD (outside Annapolis)
>
> 1980 SD1 turmeric
> 1980 SD1 aqua
>
>
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