Engine 850: B5252S/2.4/10v: GM part on 850?

[mat_g]

Hello,

My father-in-law's P-reg 850 has a GM part fitted above the radiator next to the fan relays. Apparently his garage has diagnosed this part as having a fault but aren't able to figure out where to purchase a new one. They say it's some kind of pressure regulator...

Anyone know for sure what the part is and where to buy one from?

Many thanks,
m.

[ravennexus]

it'll be the Map sensor.

the 10V engines used siemens fenix 5.2 and ran a map based system instead of an air flow based system.

you see GM 1bar Map sensors on many US NA car that uses such a system.

does it look like this


http://cgi.ebay.com/ebaymotors/1990-...21492721QQrdZ1

[mat_g]

cheers ravennexus,

i'll send that image to my father-in-law so he can check.

how would a failing map sensor affect the running of the engine? i'm not sure he's noticed anything different.

cheers,
m.

[powernut]

ive an 850 t5 turbo version which has a maf sensor on the intake which went down and the engine wouldnt idiol run right and black smoke from the rear and poor mpg also ive used a vauxhall part in place of the old one which works fine,but mines round not square like the one pictured/

[ravennexus]

a MAF is not the same as MAP.

MAF measures Mass air flow. so basically it measures how much air is flowing into your engine so the ecu can fuel how much fuel is required in conjunction with the other sensors being used by the EMS

MAP measures manifold absolute pressure. What pressure is in your intake manifold (measured from absolute so a 1bar MAP sensor is made for vacuum to 1bar atmosphere, so 0PSI on a turbo car) then in conjunction with the throttle position sensor can work out how much load the engine is under and therefore how much air is being drawn in and how much fuel is required in conjunction with the other sensors being used by the EMS

[liuleichan]

Originally Posted by mat_g

cheers ravennexus,

i'll send that image to my father-in-law so he can check.

how would a failing map sensor affect the running of the engine? i'm not sure he's noticed anything different.

cheers,
m.

Can't answer with all forms of "failing" - but what I would say is if I unplug the electric connectors to my car's MAP sensor (obviously whilst the engine is running) the engine stalls / dies.

[ravennexus]

just been out to check and that picture i posted is exactly like the MAP sensor on mine.

not checked the part code but any liner 5V 1Bar map should be usable as a replacement.

IE read's 0V at total vacuum and 5V and 1Bar (100kPa)

does make it handy if a turbo conversion was being planned as all the sensors on the engine are present for what an after market engine management system (Like putting megasquirt in the standard Fenix box) would require and a GM 3 bar map sensor (29psi boost) would plug into the stock harness