A very interesting RPM probleme

[newman02]

I had to put a new engine in my 95 eclipse, i replaced it with one from a 96 with less miles, wen we put this one i found and interesting probleme!?!?!?!?!?! when i am accelrating in 1st and 2nd @ around 45000 RPM the tach goes crazy!!!!! My engine spudders ad evrything, just like a missfire, in 3rd and fourth it desit @ 3500 RPM's, it will rev out higher than tht but not before it jumps back and fourth a bunc of times....... any got any ideas????

 

[sonicnofadz]

Hmmmm sounds like there is an electrical problem....your ecu may be screwed up, or maybe you are using sensors that are either defective or incompatible with your ecu. Did you use the sensors from the the new engine or did you keep your old sensors (crank sensor, cam sensor, etc) ??

 

[1fast97gsx]

the tach gets its signal either from the coilpacks or ignition module ... I'm thinking it's the ignition module. Its either the ignition module or the ECU imo ... maybe just a bad connection somewhere though.