QuestionI have 1998 Discovery LE that for the most part has always been reliable and runs well. Only recently I have experienced a problem where the engine seems to cut out a few times before returning to normal operation. This erratic engine behavior only happens occasionally, and has been experienced during both city and highway driving at different speeds. During these events I have never experienced any engine warning lights, dimming lights, or obvious electrical failures, but I have seen both the speedometer and the tachometer jump up and down, quit working, and then return to normal operation. It is also important to note that the speedo and tach failure is not always present during the erratic engine behavior, and visa versa. What is the cause this mysterious problem? Alternator failure? VSS? Your advice is greatly appreciated.
Thanks,
Ronnie
Answer************FOLLOW-UP****************
Ronnie,
check the following website out for VSS problem description:
http://www.discoweb.org
Click TECH header which will take to you a webpage full of repair descriptions. Towards the bottom you'll see the "vehicle speed sensor" selection. It describes what usually happens when this component begins to fail. Maybe this is what you are experiencing? Also describes how to change the component and how much it will cost (if you do it yourself).
Bye for now,
JohnMc
***************************************
Hi Ronnie,
I've had this problem too! Mostly under city driving conditions. Its a mystery to me as to what is causing this problem. It could be vacuum related, maybe fuel feed related and I wouldn't rule out the alternator.
I'd make a note of how often it happens to determine if its becoming a more serious problem.
If you are seeing sporadic tach behaviour, I'd fist suspect the alt, however, if its not the tach it could be the modified BOSCH EMS (engine management system) and this is best left to the 'testbook' technicians.
Best of luck,
JohnMc
