Check the engine. ===================================================== There is a problem with something that effects the emissions of the engine You need to have the vehicle scanned for any trouble codes to help diagnose and then repair the problem
A basic tuneup includes changing the spark plugs, wires, fuel filter, air filter, changing the oil/filter, check fluid levels, and perhaps check the engine codes.
Check the codes with an OBD2 scan tool.
HAVE AN AUTO STORE OR SHOP HOOK UP THE OBD2 SCANNER TO SEE WHAT CODES ARE
To reset the check engine light on a 1998 Mercury Marquis, you can disconnect the negative battery terminal for about 15 minutes. This will clear the engine codes stored in the computer. Alternatively, you can use an OBD-II scanner to erase the codes if you have access to one. However, if the underlying issue causing the light to illuminate is not resolved, the light may come back on.
Check the choke first to insure that it is working properly. Next check the computer codes for any possible issues that may be shown.
If the Check Engine light is lit or has lit, that means the computer has detected a fault in either the performance or emmissions system of your vehicle. Have the OBDII terminal scanned for the trouble codes.
Plug in a scan tool.
If you have the codes read and repair what is wrong with the vehicle the light will go out on its own, or can be reset by the tech.
To reset the check engine light on a Mercury Villager, first, ensure that the underlying issue has been addressed. Then, disconnect the negative battery cable for about 15 minutes to clear the computer's memory. Alternatively, you can use an OBD-II scanner to erase the trouble codes. After reconnecting the battery or using the scanner, the check engine light should turn off.
Have the codes read.
Check the computer for engine codes. Have a tuneup: new plugs, wires (if equipped), fuel filter, air filter. Hopefully that will help, if it doesn't you'll probably have to get it checked somewhere. Could be a failing fuel pump, or clogged injector. A vacuum leak or faulty sensors somewhere.