M50 Misfire unknown reason. Please help..MAF? Flat Battery?

Post Thu Oct 06, 2011 7:17 pm

Right then.

Car has been running fine last week.

All I have done is taken the air filter and MAF off and cleaned the filter and put it back.

The MAF has been left under the bonnet with the bonnet slightly open for the last 4 days.

The car has had not been started for a week and the battery was running low.

I've just stripped the interior and pulled some stereo wiring out.

Just thought I would try and start the engine to make sure all was ok....

Forgot to attach MAF and it started but popped and banged so turned it off.

Reattached MAF and restarted, and it still pops and misfires.

Battery seemed really weak on start up.

So have now put it on charge.

Any ideas on misfire? Is it a flat battery? Have I fucked the MAF? Have I dislodged a wire when stripping interior?

Help please ;)

Thanks in advanced to advice.

Post Thu Oct 06, 2011 11:24 pm

maf fitted the right way around?

Post Fri Oct 07, 2011 8:21 am

Yep MAF is right way round.......

What are the symptoms of a fault MAF?

I have unplugged it and it still misfires and stops.....

I will upload a vid

Post Fri Oct 07, 2011 9:12 am

[youtube][/youtube]

Post Fri Oct 07, 2011 10:16 am

I think it might be worth checking your coil packs still as my car was running fine for a day or two before it started to misfire and i found they all had water in them. Check which coil it is and swap it with a spare if you have one or switch it around with a known working one and see how that gets on.

Post Fri Oct 07, 2011 12:48 pm

Maf will cause bad running and in 'some' cases will run better with it unplugged. Not in my case though, it ran worse even though the computor told us it was feckered!

Coils would be a good starting point, these are common failures on these!

Post Fri Oct 07, 2011 11:34 pm

FYI........
What a twat....

2 hours of messing about! And finally I spotted the Pipe that goes into the intake in the middle had been pulled out!

The pipe in the middle..... FFS. (pS what is the silver metal thing?)

CAr now purrrrrrsssss like a kitten!

All sorted now. ;)

Post Sat Oct 08, 2011 1:54 pm

Good to hear that's sorted! and that's the Idle control valve.