Sporatic rpm increase at 2000 rpm (increases to 4000 by itself)

I had a problem with both the speedometer and odometer in a Lincoln. It may also have an effect on the engine operation. My speedometer showed 45mph standing still and miles were rolling up on the odometer.

For me, it was a bad Alternator. The alternator was shorting out through the case. You should have your alternator checked and if you find out it is good, then the problem is something that is charging the car body.

You are getting a stray current that is messing up your dash and engine controls. You may have a power wire which rubbed through its insulation.

The 1993 Lincoln Mark VIII raised the standard for Lincoln driving with a 0-60-mph time of just 6.9 seconds versus 7.7 for the Eldorado.--------------------------------------------------------------------------------------
Launch X-431 IV Auto Scanner

On this website (link below) you find fuse box diagram and description for Lincoln Mark VIII (1993 - 1998)

Lincoln Mark VIII 1993 1998 fuse box Auto Genius

Check your Tran oil pump or torque converter

On this website (link below) you find fuse box diagram and description for Lincoln Marek VIII (1993 - 1998)

Lincoln Mark VIII 1993 1998 fuse box Auto Genius

Don't bother. Check with srtutmasters or other alternatives. If the car was made in 93, all bags will be leaking and eventually the compressor cant keep up and fails. even your local lincoln dealer will not be able to diagnose the problems with their "computers." You can get lifetime struts and spring, in your case just springs for the rear, lincoln shocks still work. Put new struts and springs in the front. The only difference is the car will not lower itself at 60 mph or higher. the ride is the same.

Mine did same thing. I have a 95 Mark VIII LSC and took it to dealer after troubleshooting for two days. Turned out to be Throttle Position Sensor. With Diagnostic fee it cost about $350 including labor. Hope this helps- Mike

Try to have the mechanic look for "downshift kickdown" service info. When you are driving and the cars computer senses a load that is beyond the limit of the present gear, the car will downshift into a lower gear to match the load.
The inbetween gear time is when the RPM rises because the gears want to change and the transmission has not caught up with the engine.
Some of this can be adjusted with the hydraulic pressure in the transmission. The torque converter supplies the pressure and the rebuilt trans needs to be matched with the torque converter.
Go back to the trans shop.

WHERE TO FIND THE BRAKE LIGHT ON A 1993 LINCOLN MARKVIII

buy a set of factory manuals used. There is not just one picture.
the fuse box in the driving area is in the owners manual. The engine compartment diagram is in a book called Mark VIII Electrical Vacuum and Troubleshooting Manual.