Low revs variation

If it's got a synergy fitted check the wiring out I've just fetched an Mg from birmingham and barely made it home, misfiring, late fuel detonation and loads of smoke.
although it was unplugged off the maf it wasn't off the rail and the wiring on one of the pins came out of the plug as I investigated

crownwheel said:

Rover is a 75 CDTI. Not a "problem" yet but want to find out the cause in case something serious is just round the corner.
At 30 mph in 4th there is what can best be described as slight "hunting". Just a regular slight variation in revs which can also be seen on the rev counter. Tickover is smooth and at any higher speeds and there is no problem evident. Power and economy are excellent even after close to 200K miles.
Any thoughts from the Rover gurus out there?
Thanks in advance.
John

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Could be just one injector starting to have a leakback issue. If so it would probably be noticed more at lower revs. Good high mileage on your engine though and hard working bits do start to wear out.

Hi TS / Colvert
Thanks for replies.
No Synergy and not likely to be MAF sensor as it has not been connected for last 100K [tried non-OEM replacement but it didn't work either]
Injector leakback looks likely option and assume a wee shot of redex is no longer a likely cure. Since problem is minimal at the moment and a further assumption is that injectors fail gracefully then I should have a good few miles left before attention.
PS - looking at some recent threads on fuel consumption, my CDTI gets about 50 + mpg on 120 mile/day trips with 110 miles on motorway or fast "A" road. Travelling at limit and using cruise as often as possible with occasional heavy foot.

PPS - Thanks forum for advice on rear spring changing as I had to do both sides last weekend.

John