Ford Repair: 1995 Contour Automatic 4Cyl, crankshaft position sensor, problem whit

Question
Would the flywheel make the car idle erratically and lose power during acceleration?
This was happening before I replaced the engine. During the replacement of the engine, I noticed the Flywheel was not complete flat. Then the exactly same problem whit the new engine. The car stumbles and jerks badly,it only calms some times when I'an going at 45 mph or more.

Your Help will be greatly appreciated

Answer
Hello and thanks for the question...I'll try to help.
 If you have the 2.0L engine ----the fly wheel IS the trigger for the crankshaft position sensor. If you have the 2.5L eninge, this is not the case, the trigger wheel is on the front of the engine on the crankshaft dampner. If the fly wheel is damaged in ANY way, it needs to be replaced for the engine to run correctly.
Hope this helps,
Erik