O2s- Does my car have one?

[4x4_Welder]

Ok, I have heard mixed info on my 81 Hatch 4x4. I have been told that it does and also that it doesn't have an O2s. I have looked, and the cat is stamped with Subaru, looks factory, and has a flat spot where the sensor would go, but no hole or threads. There is also not a single wire connector that I can see anywhere around the firewall/strut tower area. It only has one solenoid to the pass. side rear of the carb, to vent vacuum to the secondary actuator. There are no actual solenoids on the carb itself, the only wire that goes to it is for the choke.

So, is my car supposed to have an O2s or not?

[GeneralDisorder]

Only if there is an ECU under the dash. But it sounds like no.

 

GD

[4x4_Welder]

See, that's the confusing part- it has a little black metal box about the size of a paperback book under the steering column with a green LED on it, and it says Japan Electronic Control Systems Co LTD, Japan on a silver tag. But I can't figure out what inputs and outputs it uses, especially if there is no feedback from an O2s.

[GeneralDisorder]

Then your engine and exhaust was likely replaced at some point as there would be no reason to have the ECU without it's 02, and duty solenoids.

 

#1 - what's the engine serial number?

 

#2 - what does the vacuum routing diagram under the hood indicate?

 

#3 - I'm assuming the paperback sized unit is fully connected into the harness with two or three big connnectors right?

 

#4 - does your ECS lamp ever illuminate?

 

GD

[4x4_Welder]

The diagram shows two duty solenoids, one is there but not hooked up. The engine probably has been replaced, it has an inconsistant seriel number, but is still a solid lifter engine. Also, no secondary air injection.

The tag under the hood says catalyst, but doesn't say anything about electronic control or feedback.

There isn't an ECS light as near as I can tell, I have never seen it light up.

 

I'm about ready to strip all this crap right off it, but I need this thing's cargo capacity on a trip to CA later this month.

[GeneralDisorder]

Feel free to remove that stuff then. The EA81 ECU's don't really do a whole lot, and it will run fine if you just remove it. Sounds like it had some problems in the past and rather than fix it, they just slapped on a non-feedback carb. The exhaust may have just been a coincidence and may have been replaced for unrelated reasons.

 

It's got an ECU, and the proper vacuum diagrams for it on the hood (shows the duty solenoids), so it's a 100% gaurantee that it *did* have an O2 at one time, and it did have an ECS light - I think it's part of the tell-tale on the 80/81 cluster. They could have removed the bulb easily - they were possibly hessitant to remove the ECU thinking it might mess something up. Unlike the EA82 feedback's, the EA81's do not control the fuel pump so there's no harm in just pitching it in the dumpster. My 84 wagon was a feedback, and shortly after converting it to a Weber I pitched the ECU.

 

It's too bad you don't still have the O2, as that would make it easier to convert to SPFI. They can be welded in pretty easily tho.

 

GD

[4x4_Welder]

Oh yeah, I have five or six O2 weld-in bungs in my toolbox from when I played the exhaust shop game. Gives me an excuse to cut up that portion of the exhaust too, though.

[GeneralDisorder]

Make sure to put the O2 in the cat. It will help it reach operating temp quicker, and keep it from dropping out of reporting range when idleing for more than a few minutes. Or use a 3 wire heated unit. But you probably know all that if you played the exhaust shop game ;o)

 

GD