I have a 1996 Landrover Discovery that after driving for about an hour it looses almost all power and won't go more than 30 mph. When at a stop the speedometer (dial) shoots up to about 60 mph then comes back to normal. Ran a diagnostic...code said: cylander 7 misfire? I have no repair manual - what is this? Please advise and thanks.

 

I had a similar experience last weekend. Which went a way after letting the truck sit for an hour. After doing a lot of research I found that this is caused by a failing VSS (vehicle speed sensor). Do a search on that in this forum or in LRO and you will see. I ordered a new one from BA for $90. I was able to verify that this is indeed the failing part by using an ODBII reader that can display live sensor data. When the problem occured again I plugged it in and the speed the ECU was seeing from the sensor was oscillating between 60 (my actual speed) and 119mph. When the ECU sees a speed above 110mph it cuts the fuel to the odd cyclinders. Hence the lack of power.

Check out discoweb, they show you how you can replace it, its actually pretty easy. In the mean time if you need to drive it before the new sensor gets delivered, simply unplug it from the wiring harness. Your speedo and odometer will NOT work, but your truck will be drivable.

Hope that helps
Andy

 

Fix the vehicle sensor first, I don't think the cylinder 7 misfire is related, but I guess its possible....

 

Don't go jumping into parts untill you know for sure what is wrong. # 7 cylinder probably has a bad plug or wires, how long has it been since it had a good tune up, what about your fuel filter, when was it last changed?

 

Mike,

Would the fuel filter affect the speedometer?

Jared

 

i have recently changed out the plugs and wires w/in the last two months, hoping that this would resolve this issue, but it is still occuring.