Ok, before you do ANYTHING else, take the coils out and see if the Spark Plug tubes are filled with oil or water. If any of them are, (and on older unmaintained cars they always are usually) it can cause everything from rough running, stalling, misfires to just about everything.
And its a quick no cost check.
Had a POETS afternoon so had some free time to fiddle with the car. Re-connected the battery, tried it and she fired up, ran for less than a second & then cut out. This was repeated half a dozen times before I gave it up as a bad job. I disconnected the MAF and whipped off the air hose between the filter & throttle body and checked it, a bit grubby but not 'minging'. Also appears to be intact, no splits or anything.
Next stop was the plugs. They are fun, aren't they? Eventually got all the coil-packs and leads out of the way, number ones plug bores were both full of oil. Cleaned that out, then pulled all eight plugs, cleaned them off checked the gap and stuck them back in. And then thought to myself "I'll just try that". It fired up first time and ran like a dream, no fluctuation of revs. A bit of smoke but that's down to some of the oil that got into number one bore. It stopped soon enough.
Great, I've fixed it! So I switched her off, refitted the air hose and MAF. Fired her up and she ran for a second before cutting out. Same happened with repeated restarts.
So I have disconnected the MAF and she runs like a dream. Steady idle, came up to working temp as expected, ran like a dream on the test drive and full range of revs. By ****** does she take off!
So it looks like my MAF is shagged. Typical, I need an £85 part for a £100 car! oh well, at least she is driveable. I'll get her to the garage, have a diag session and an MoT before I invest in a MAF. No point spunking £85 out if my floorpan is rusted out and all my bushes are shagged (slight clonk from rear left under hard acceleration)