I have a 420A in my 98 eclipse and I have the error code 1390 meaning timing belt could have skipped a tooth, well to fix it they said check the cam/crank sensor and check for a damaged belt. Well crank sensor was good and bought a new cam sensor. I put the new sensor on and now the motor is sputtering below 1kRPMs, smokes like hell and stalls. I dont know much about the timing and such any help is greatly appreciated..

EDIT* Also is the timing belt skipping a tooth would the car idle unstable because it idles steady between 900-1100RPMS...

 

The engine will run terribly if the timing belt is off one tooth. Do not drive it in this condition as it may eventually skip another tooth of come apart althogether. Tow it in for service and have the belt replaced ASAP.

Joel, CA

 

Ok well the engine runs perfect... has a lot of power and runs smoothly... it just sputter really badly when I put the new Cam sensor on there... but if I put the old one back on it will run fine again. Maybe the new sensor requires the PSU, Signal output and ground in a different order on the cam sensor... The engine runs fine so the belt shouldnt have a skipping tooth.