Member Since: 24 Jan 2010
Location: strathclyde
Posts: 334
I dont know whats inside the little hole in the MAP sensor or how this one specifically works, but if its like the pressure sensors I have worked on in high vacuum systems, it might be a heated filament type of sensor, and the amount of pressure (or vacuum) in the chamber causes the filament current / voltage change in proportion . this way it senses the pressure in the chamber. if you squirted something into the hole of the sensor it could damage the filament or outgas giving false readings.......hence unless you can dry it out you may need a new MAP sensor.......
26th Apr 2011 9:12 pm
buda
Member Since: 24 Jan 2010
Location: strathclyde
Posts: 334
looks like its a piezoelectric sensor that varies the voltage in proportion to the pressure.
It is not just an on/off "switch", and squirting cleaner or anything into the sensor port may cause false readings from the sensor.
It would be interesting to see if the fault codes pinpoint to the sensor..........let us know how you get on....
good luck.
26th Apr 2011 9:39 pm
character
Member Since: 01 Jan 2008
Location: wiltshire
Posts: 5781
reminds me, must go and collect my NEW map sensor tomorrow from the stealers before someone robs it by mistake
26th Apr 2011 9:55 pm
Mr.Pastry
Member Since: 24 Nov 2010
Location: South Wales
Posts: 482
Thanks for the advice.
I gave the Map sensor about 10 minutes to dry before refitting and giving it a go. I use this switch cleaner frequently & it evaporates really quickly. I guess if there is more muck still inside the sensor, it will take longer to evaporate.......
I have just tried the car again & it started & idled normally. I'll give her a run in the morning.
I spotted this bit of info a few minutes ago.
The Manifold Absolute Pressure sensor (MAP sensor) is one of the sensors used in an internal combustion engine's electronic control system.
Engines that use a MAP sensor are typically fuel injected.
The manifold absolute pressure sensor provides instantaneous manifold pressure information to the engine's electronic control unit (ECU).
The data is used to calculate air density and determine the engine's air mass flow rate, which in turn determines the required fuel metering for optimum combustion (see stoichiometry).
A fuel-injected engine may alternately use a MAF (mass air flow) sensor to detect the intake airflow.
A typical configuration employs one or the other, but seldom both.
These pictures are not the best but you can see it was quite mucky.
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I really fancy getting a faultmate. Was there a discount for forum members?
Admin note: this post has had its images recovered from a money grabbing photo hosting site and reinstated Mitsubishi Outlander Phev 4H 2018.
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26th Apr 2011 9:57 pm
MacLeod 313
Member Since: 18 Apr 2008
Location: away
Posts: 10723
Mr.Pastry wrote:
I really fancy getting a faultmate. Was there a discount for forum members?
There is a 10% discount to established forum members, I would give BBS SPY a PM for a quote.
26th Apr 2011 10:02 pm
jsamuelson
Member Since: 07 Feb 2011
Location: Cornwall
Posts: 214
I didn't disconnect mine when I cleaned it, nor did I use any kind of cleaner - just a wipe and a needle to scrape out the very end of the tube. Been fine for two days now. But others in the MAP thread have used WD40 or contact cleaner and didn't seem to have any problems.
One person mentioned the Disco was reluctant to start after...maybe same problem?
Hope it dries and stays fine.
I would have thought that the location of the sensor would mean it's pretty robust.
26th Apr 2011 10:05 pm
Grease Monkey
Member Since: 24 May 2009
Location: Essex
Posts: 134
Hi there
Does anyone have a part number for the MAP Sensor? Just in case...
Cheers
GM
26th Apr 2011 10:08 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72798
character wrote:
reminds me, must go and collect my NEW map sensor tomorrow from the stealers before someone robs it by mistake
NoDo$h has mine, hopefully he won't start an auction.
26th Apr 2011 10:20 pm
C6REW
Member Since: 10 Mar 2007
Location: Devizes, Wiltshire
Posts: 576
When cleaning these sensors it is critical you don't stick anything solid in the hole.
A pressure sensor works by movement of a diaphragm, which is a very thin sheet of material, normally metal. Just touching this with your finger can be enough to throw it out of calibration. I appreciate these cannot be touched by your finger, but the principal is the same.
I am concerned that you mention attempting to start without the sensor connected. At a wild guess you may have introduced a fault that now needs clearing. Perhaps you need to reset as suggested?
Best regards
Chris
27th Apr 2011 5:27 am
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72798
Just clicked, error was before starting, so would be no pressure difference. If engine is reading difference from 2 sensors in the system check it would explain a hissyfit.
27th Apr 2011 8:07 am
grzesiul
Member Since: 11 May 2008
Location: UK
Posts: 6266
i would only clean it with alcohol based stuff which dries in seconds WD40
27th Apr 2011 8:25 am
dasdais
Member Since: 03 May 2010
Location: sussex
Posts: 73
hope fully my new sensor comes tomorrow if factory got one. Land Rover advised very common issues the problems I have got since cleaning the sensor.
Be advised £149.39 inc. VAT!!!
27th Apr 2011 9:11 am
Mr.Pastry
Member Since: 24 Nov 2010
Location: South Wales
Posts: 482
I have had the great pleasure of driving the wifes Astra today.
The Discovery was left at home all day.
I just took her (the Discovery) for a run & gave her a "good seeing too" with the loud pedal.
She is running perfectly normally now. I guess the map sensor had not fully dried out.
The best news is that I have decided to buy a Faultmate FCR.
I'm sure it's going to be a great comfort having it handy in the glove box.
How are you getting on with your map sensor dasdais? Have you resolved the issue?Mitsubishi Outlander Phev 4H 2018.
Mitsubishi Outlander Phev 4H 2015 - gone.
Discovery 4 HSE - gone.
Discovery 3 S - gone.
Discovery 3 - gone.
Discovery 1 - gone.
Defender 90 300TDI - gone.
Defender 90 200TDI - gone.
Landrover 90 19J - gone.
Argocat 8x8 - gone.
Argocat 6x6 - gone
RR/LR V8 Hybrid 100" - gone.
Rangerover Classic 3.5 - gone.
Series III 2.25- gone.
Series IIa 3.0V6- gone.
Series I - 80" gone.
27th Apr 2011 8:07 pm
dasdais
Member Since: 03 May 2010
Location: sussex
Posts: 73
fixed????
Tomorrow I have to decided if to buy a new sensor or not. Tonight had error messages still after leaving home all day. Had to fit new wheels this evening so tried getting suspension to raise turned engine on and off 4 times but nothing.
So put hazards on and tried using key fob to raise 3 attempts nothing.
Went back inside and re-started and !!!!!!!!!! all error messages gone? started up, suspension raised and drives perfect although if stop at a junction and let idle, engine fault displayed on screen and it stalls??
Shall I bite the bullet and buy the new sensor as maybe its sort of ok now but never going to be perfect or will this rectify itself???
27th Apr 2011 9:16 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72798
Good she's playing again (EDIT Partially, didn't read above fully)!! Hopefully the ghosts have left (or are leaving) the machine. In the grand scheme of it a MAP sensor is small potatoes, certainly considering what I've spent.
Sounds like whatever was in there has evaporated off and it's back to normal, but I'm not a techie and that's just a "sounds like"!! Worth having one just in case. If you don't use it and Hitachi can't make anymore then you could sell it for a fortune later on!!
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