Disco 2 V8 Misfire, now fulling my hair out!

Hi All,

well as you can guess from the title the last few days have been some what stressfull.
It all started a few days ago when my 2000 disco 2 developed a misfire and lost all power when going up a hill, I took it home, and noticed a rather large amount of white bubbles in the header tank. Thinking the worst, i got stuck in. heads came off, skimmed and refited with new gaskets, (confirmed the old ones had gone) and started her up... Ran great, nice and smooth, i have a Hawkeye so pluged it in and everything seemed great, untill..

I drove down the street got about 500m turned around, tryed to come back up the hill, and no power!!! very sluggish, i mean i thought i would have too push!... pluged it back in and multiple misfires on all pots, and mass air flow sensor fault...

Surely this sensor cant cause all this??? ive gave up for the night and decided to come in, thinkin i will have some sleep and start with a fresh head in the morning..

Has anyone got any ideas?

thanks

bit of an update, ran fine this morning for about 5 mins and then the same thing... no power, really strugging