97 impreza- all 4 cylinders misfire

I have a 97 impreza outback, standard transmission, 113000K The check engine light has been on for 3 months now with me fighting to find the cause. The codes are and always has been misfires detected in all 4 cylinders (a seperate code for each cylinder). Already I have change plugs, wires, ignition coil (all subaru-brand parts). Also the air filter and fuel filter just for fun! At this point the light still kept coming back on. After I reset the CEL about the

3rd time, the light finally didnt come back on .... for 1000k. I have since check my coolant to make sure it is still green... suggesting that a blown head gasket is not the cause. I also checked the female pin connector parts that connect to the ignition coil adn they seem to fit snugly with the pins on the ig. coil. The car runs great, even the subaru specialist I took it to said so! You cant tell its misfiring...no loss of power, idles very quietly... even when the light is flashing, and yes I know flashing is a bad thing. The light flashes mostly when the cars is about 3000rpms at 70mph or at 3000rpms going up a hill... but every once in awhile it choses to flash randomly, for example when I am idling at 500-700rmps at a stop light.

Any other suggestions as to the cause? I do have slight oil leak from somewhere. Oil just accumulates on a pan at the bottom of the engine and burns off during long cars trips. Could this be causing misfires somehow if the oil is getting in somewhere it is not supposed to? Why would the light go out for 1000k and now be on all the time? And why cant I tell in the performance of the car when all four cylinders are misfiring?

I just want to cover the light with black electric tape :)

Thanks! Lara

Reply to
Lala
Loading thread data ...

Reply to
Carl 1 Lucky Texan

Good morning,

Check if the earthing of the engine and the ECU are good. Check the wiring between the Engine and the ECU. There are a lot of connection on the left side of the enginebay . (located near the gearbox oil stick) And you can always check the connections of the ECU.(located at the passenger feet). Newer cars can have a lot of problems with wiring. The ECU depends on proper signals.

Gr. Walter

Reply to
w.milaan

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.