Righty-ho.
I fitted a bosch sensor (brand new - out of the box) - and then decided to pull the engine and make sure all was fastened up properly....
Please... before asking why - please read my profile - it's a car that my dad wanted to see running again, but on the 8th of October, he lost his fight with Cancer - and didn't see it running.....
anyway.... the point is....
I first got the car... it wouldnt rev up and lots of black smoke.
disconnect the MAF and it revs - although there is still a bit of smoke...
I fitted a new one about 8 weeks ago, and it ran perfectly - (well.... the engine ran perfectly)
After completely cleaning the Intake manifold - fitting a Crank Case Breather Valve and Filter 0 new Vacuum Hoses EVERYWHERE - EGR Blanking MOD - Polished machined Aluminium.
Because the car had a bodge job engine fit (again please read my profile before asking why)- no bolts / brackets missing everywhere.... I took the engine and box out again - ordered new bolts (back order for many) - LUK Slave Cylinder (GETRAG BOX) - BearMach Master Cyclinder - New Front ARB Drop links - Front Wishbones front flexi pipes - yada yada yada.
Today; I refitted the engine - PROPERLY this time - all the new kit and fired up the car....
turbo is whistling a bit... (probably to be replaced later) - but it wouldnt rev again.... lots of black smoke....
Usual MAF Sensor problem.... runs like a dream with the MAF disconnected.
So.... It's a genuine Bosch Sensor.... it DID work... but......
Could anything be causing these sensors to fail regularly...????

Could be a vacuum leak, the turbo isn't spooling or both?

Could anything be causing these sensors to fail regularly...????

Click to expand...

if unfiltered air was being sucked in from somewhere between the air filter and maf sensor ..
then in theory the maf sensor hot-wire might get dirty fairly quick ..
e.g. a small air gap by the maf sensor housing ..
or an air filter that's not fitted right 'n letting unfiltered air into the intake ..

( mentioned cause i noticed my air filter gets 'black dirty from air drawn in via the air filter housing water drain holes
( i know cause the 'black' .. soot and or oil i imagine .. make darker spots that line up with said drain holes

also on hippo's that don't have the air-intake-temp. sensor mounted on the intercooler hose
they take the same sensor reading from the maf sensor ..
if the a.i.t. sensor goes 'open circuit' then the ecu uses a default temperature data of 'minus 5c' ..
which causes more fuel to be injected as engine ecu thinks there's more air flowing in than there actually is ..
result is black smoke out the exhaust ( i.e. unless outside temps be actually That cold ..

or something is overloading the maf's electronic circuitry ..

i guess you could ask 'rover ron' ( of synergy / ronbox fame )
he has his own sub-forum on the 'mg-rover forum' site
( http://forums.mg-rover.org/forumdisplay.php?f=139 )

Just 2 ideas. Is your manifold cracked, they are plastic and have failed before. Have you replaced the M.A.P sensor, left hand side of the manifold? Although for 2 to fail so quickly, might be worth checking the electrics.

erm...... the rubber hose n the "air" side of the turbo.... should it have a jubilee clip on it??? - you know the one.... when the pipe isnt fitted properly - you get black smoke, no revs... almost a MAF sensor fault - :-(

Actually.... after doing an engine swap, I found that this hose wasn't the culprit..
i was the victim of a faulty batch of sensors.....
All fixed now!