Grand Am missing

[james11]

I have a 95 grand am with a Quad 4 engine,duel over head cams. When the car is cool or at slower speeds it runs fine and idles fine, but while driving on the freeway for 15 min. or so it will jump or miss like there is water in the gas.I have replaced the fuel filter, coil packs, tower, and plug connectors, the miss is better but it still misses when the car is run on the freeway @65mph for 15 min or so. Anyone have any ideas

[GTP Dad]

Welcome to AF!!

There are several possibilities first I assume you also put in new plugs when you changed the connectors. I would start with the fuel pressure to see if it is correct for a warm engine. If so then I would look at the ignition modules as they can often cause a miss when they get too hot.