Hi Guys, Merry Christmas........i have a v8 d2 that has a flat spot that doesn't happen if the air flow sensor is not connected........is there a quick check with a voltmeter i can do to check if the sensor is poorly, it happens on gas and petrol but on neither if maf is dissconnected....i have fault mate but it just shows misfires which is because it takes a lungfull of air before the fuel gets in i'm assuming....if i reset the adaptives it is fine for a while and then slowly degrades.

Any suggestions?

Cheers Nick.

Ahhh the joy's of car ownership......had a bit of a poke around and could hear/see fssss...steam, fssss...steam, fssss...steam.....there is antifreeze dripping from underneath the cylinder head/manifold on cylinder bank one right onto the lambda sensor which explains where the small amount of water was going and why the car is now (on the way back from shopping) running like a bag of pooo and why there is an intermitant fault and a misfire.

I like Faultmate but i wish it would say stuff like "The cylinder head gasket is buggered mate!".......best get my scruffs on then!



It always seems that i am dismantling V8's at Christmas.....

If the MAF is buggered the Faultmate should pick it up with either a fault code or some funny air flow readings in the live data.
Reason why it runs better after the MAF is disconnected is probably due to the ECU reverting to open loop default fueling when it detects a problem with the air flow meter i.e it being disconnected.
I have also found when running on LPG that the tune drifts after a time & needs an adaptive reset, mine tends to run the trims too weak after around 4k miles, next step is to get LPG ECU retuned & see if it's any better.
Looks like you may well have found one of the problems with rough running with the head gasket though, mine went in a similar place 2 years ago just leaked coolant over the exhausts, replaced both head gaskets which upon removal wernt far off blowing between cyls 5&7. I also had a close inspection for signs of shifted liners of which there were none despite a local V8 specialist being convinced I would be back very soon after looking at the engine soon after I got the car, that was 3 1/2 year ago!!