Land Rover Repair: Stalling/Black Smoke, vehicle speed sensor, throttle position sensor

Question
Hi John

After your suggestion I did some searching on the TPS and came across this website http://www.goingfaster.com/spo/electronic_engine_management_sys.html which has a nice table with symptoms and causes. By process of elmination (starting with black smoke) the two most likely causes would seem to be the MAF sensor or the MAP sensor. Since there us also some pinging/knocking, the MAP sensor is most likely. The only missing piece is that I dont get a check engine light.

Do you think it could be the MAP sensor?

Mark
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Followup To
Question -
Hi

I have a 1996 Discovery. Often when I stop the car the the revs will rise and fall between 0 and 1000 and then the car will just stall. When I am accelerating hard and the revs get quite hign it lets out a big cloud of black smoke just as it changes gear. Fuel consumption is also really high and there is often a strong smell of petrol after I turn it off.

What I have been able to find on the net suggests that it could be the air flow meter or ECU. Since these are both quite expensive parts I would like to eliminate other possibilites before looking at replacing those.

Any ideas
Answer -
Hi Mark,

it could be the MAF or the ECU but most likely the TPS (throttle position sensor) of VSS (vehicle speed sensor).

I lean towards the TPS as I had this problem with my '95.  Dealer said it was the ECU but I refused to believe it...especially with a $3500 repair estimate.  Turned out to be the TPS and a $550 repair bill.

Try this website as well:  www.discoweb.com


Best of luck,

JohnMc

Answer
Hi Mark,

I've checked all my notes and links and have not seen a MAP sensor mentioned.  The best solution is to have your Disco analyzed by a LR testbook diagnostic system to isolate the problem. The MAF sensor is very expensive and should not be swapped in or out 'on a hunch'.

Your '96 Disco has little 'tweaking' capabilities due to the modified engine management system.  If your too rich or too lean, only the proper diagnostic machine can adjust this.  I wish I could give more help but that's about all I can do from here.

Best of luck,

JohnMc