Today it was cold when I started the disco up. It took alot of turning over but eventually it fired up. If I revved it, it revved ok then dropped to 250rpm and took forever and a day to pick the revs back up again. about 30 seconds before the revvs went up with foot stamped on loud pedal. I set off on my journey and got to the end of my road which is on a slight hill. revs dropped to 250rpm, took ages to build back up then as revs were on way back down again I had to dump it into Drive and just stomp the loud pedal.
I did put in 15L of diesel into my 20L diesel tank. I am guessing some of this has veg oil in. Probably 50/50mix by then? Stab in the dark guess. As soon as the engine got hot and I went to veg oil all was cured.
This to me says 2 things. May mean more. Insert your comments but mine are....
1 Veg oil / diesel mix in cold the engine didnt like it so struggled to do anything useful.
2 My cold start system has packed up. In my Rover 620 petrol when the engine is cold it revs 500rpm higher than normal until the engine gets warmish then it drops to normal revs. should a diesel do this too?