I have been working to identify a problem over the last couple of weeks. I have a 960 wagon with 174K miles. Four weeks ago, I would start it up, it would run rough for a minute, then smooth out and I would be on my way. Three weeks ago, besides the rough startup, it would hesitate and surge when I would drive. I would step on the gas, it would stumble and choke, then pick right up. This would continue until the car got nice and warm. Two weeks ago, all the same issues but now it would stumble even with the car warm. I changed the plugs, air filter and ECT, cleaned the IAC with no luck eliminating the problem.

Yesterday I was driving on the freeway doing about 75, when all of a sudden it seemed like the car stumblen, jerked hard, dropped in RPM, stumbled and then pick right up. The more I pressed on the gas, the worse it got. I had to let off the gas and then gingerly press on it to keep going. If I was too agressive it would kick and jerk again. I got off the freeway, stayed in the right hand lane and took the back roads home. Three hours later I finally got home. Never could go over 35. If I would try, eventually it would jerk, forcing me to back off the gas. The tach dropped each time it jerked. I was within a mile of my house when the problem disappeared and it ran fine.

This is the worst kind of problem because it's intermittant. I just drove the car around the block and it ran fine. Any helpfull ideas are welcome.

I plan to change the TPS and both Knock Sensors. I've read this could cause similiar problems.