1995 Monte Carlo starting trouble

My '95 Monte Carlo 3.1 runs like a brand new car … IF I can get it started . Sometime at random ( hot or cold ) there is no response when the key is turned . If I jump the starter with the key in the “ON” position engine will run for about a second and then quit . Sometimes if I jump the starter with the key in the “OFF” position and then turn the key it will fire right up . I have run good strong grounds from both angine and body to the battery , and have cleaned the terminals on battery , as well as on every single fuse and relay in the car. Very randomly again sometimes at road speed the engine will just cut out a number of times for a minute or so and then straighten out . Again randomly sometimes while driving the “SECURITY” light will come on . This does not affect whether or not the car will start again . Any help would be appreciated . Thanks : Don

If your ignition ‘pass key’ has been dropped on hard ground it may have damaged the chip in it and cause ignition problems.

This may be causing the ‘security’ light to come on and the engine to cut in and out through vehicle vibration when in motion.

Have you tried another key programmed for this vehicle?

Other than this, I would suspect a damaged key cylinder. (steering column)

Also: check Cougars’ response in todays post “2002 Monte Carlo…”

A damaged key cylinder, as mentioned, or a bad ignition switch. The switch for these cars, I believe, are actually located on top of the steering column. The key cylinder is attached to a rod that moves the switch. Not sure if this same design is on your car. Many car makes have a separate cylinder and switch, which can be replaced independently. But, I have had some imports that are combined.

With the security light flickering on and off, it could also be a problem with the chip reader in the key cylinder or the security control module itself. Not familiar enough with this vintage of GM to know where to go next.

Yes I have used both keys and it hasn’t made a difference . I will check the ignition switch thank you .