Ok not sure if this is the cause of your problem but something you could look into
I found a recall listing for your vechile
99V194000:FUEL:THROTTLE LINKAGES AND CONTROL
NHTSA RECALL BULLETIN
Reference Number(s): 99V194000
Model(s): 1998 Ford Contour
1998 Mercury Mystique
1999 Mercury Cougar
Campaign No: 99V194000 Mfg. Campaign No: 99S19
Number of Affected Vehicles: 153000
Beginning Date of Manufacture: 1997 JUL
Ending Date of Manufacture: 1998 APR
DESCRIPTION OF DEFECT
The accelerator cable may have been manufactured with a burr on or near the end of the cable sleeve interior.
CONSEQUENCE OF DEFECT
This burr could fray the core wire resulting in the accelerator not returning to idle when the accelerator is
released. This condition can result in the throttle sticking, binding, or causing high engine rpm.
Dealers will install a revised accelerator cable that has a flared conduit sleeve end and molded on end fitting.
Owner notification is expected to begin during August 1999. Owners who take their vehicles to an authorized
dealer on an agreed upon service date and do not receive the free remedy within a reasonable time should
Thursday, July 17th, 2008 AT 10:22 PM