My cars running a little rough and overfueling. I spoke to Graham Quick and he said it sounded like a dodgy MAP sensor to him.

I've just been looking at pics of me motor and I've noticed I've mounted the MAP sensor on the plastic heater box cover not on the chassis. Will this be the cause. Does it have to be earthed?

 

I've ran them without being earthed to the chassis with no problem.
I can't make out yours in the piccie, but they do have to be the right way up, and are normally below the engine with bends in the pipe to stop fuel vapours getting in.
tabetha

 

Its behind the inlet manifold leved with the FORD logo. The vaccum for it is the red piping whihc comes from the inlet and t's off to feed the boost gauge and FPR aswell.

 

ive got mine on the heater box . but have run a wire to the battery earth just in case

 

I did wonder if that was it, will be ok so long as in same plane as original, ie same way up etc it's vital, they have their own earth in the 3 pin connector, the body one is to help with picking up any stray interference, all I can say is the cossie ones didn't.
tabetha

 

Make sure u have no water in the pipe and you must not tee of this pipe for other vac sources

Paul

 

Trouble is I've only got one vacum take off I can use and thats the one on the front thats T'd off. Looks like I need to add another one then.

 

Looking at your pic muz i can possibly see 2 issues 1st being the vac take off (very near thottle body) and the air charge temp which could possibly being masked by the tube that its sat in

Also the map needs to have a short as poss bit of pipe on i'd drill and tap the underside of manifold plenum in the centre for this imo

Paul

 

thats interesting which way up should the map sensor be on 2wd cosworth.
I have a kit car and i put the map inside the car and not under the bonnet also its upside down i think [ pipe at bottom].
Paul.

 

pipe at bottom which is correct