Hi guys, I have the following problem: If I drive about 70-90Km/h in the 4th gear I have quite a jerking and this is annoying when driving. But as soon as I drive faster or the accelerator pedal goes through a little bit more and the car still leaves in the 4th gear the jerking is gone. And it is also only in the 4th gear. I had the problem about 1 month ago before. However, there was also the fact that if I have passed through the accelerator meter the jerking was worse. The following parts are replaced: Automatic transmission filter + oil, 6 spark plugs, distributor cap and distributor finger. As I said: I replaced the parts and it was absolutely quiet for about 1 month. Does the Firebird have anything else in the direction of problems? I suspect that the problem comes from the direction of ignition. Can it also be the reverberator? Thanks for your answers!