Some of the checks I have finally managed to do....

MAF sensor disconnected to test but couldn't feel much of a difference if any (would it be an obvious difference??) This was replaced about a year ago as garage said that was the problem but it didn't,t solve it. I did my check just in case the replacement was duff!

Checked the ECU plug - clean as a whistle.

MAP sensor is clean.

Changed the fuel filter.

Will keep you updated - thanks for all your input!