what does ECS stand for on my 1984 gl wagon fwd only comes on after you drive it awhile:confused:

I believe ECS stands for 'Electronic Control System'. If the light is turning on then something needs to be checked possibly in the drive train system or engine.

Yup. You have the infamous feedback carb system.

You need to check the codes on the ECU. Remove the cover under the steering column and there will be a black flat unit mounted under the column. Theres a red LED that flashes, giving you a code sequence. You need to connect 2 green plugs together to start the u-test mode.

Heres a link to how the codes are read and the results.

http://www.ultimatesubaru.org/forum/showthread.php?t=49918

I had a similar problem on my 84 GL wagon, it would start and run fine. About 10 minutes later it would throw the ECS error. I looked for those green connectors for a couple of weeks until I realized they aren't there. They seem to be on newer cars. There is another thread that discusses the early ECS systems on these cars, they are quite primitive and don't store codes. You will need to look at the flashing LED when the ECS tosses the error. In my case it turned out to be a broken coolant thermosensor. I found out the computer was expecting to see a 400 ohm signal when the engine warmed up and a 4,000 ohm signal when cold. The thermosensor was open. I haven't been able to find a thermosensor at a junkyard, and Subaru wants $40. I wired up a 400 ohm resistor and the ECS light went out. Of course this does make cold starts a bit crankier...

My '83 had the same symptom (many years ago). Turned out to be the thermo sensor as mentioned above. Replaced it..voila, problem solved.

 

Please post your progress on solving this one:) .

 

Just my 2 bucks