I have an '81 4WD M/T 1.8 California model hatch. I removed all the feedback/emmissions stuff from the engine compartment a long time ago. I have an '83 hitachi carb in right now with non-feedback jetting, and I am wondering if I switch out the ECU to one from a non-feedback hatch if it will help mpg's or overall driveability, or even just idle stability. Or should I just unplug the ECU since the non-Cali '81's didn't come with ECU's?

 

If I should swap, will an ECU from an '89 hatch work? Any thoughts on the best (most compatible) year. I have a couple '84 hitachi carbs I am going to rebuild to swap out the '83 also. The '83 works pretty good (25 city/31 hwy grandma style driving), but pretty good isn't good enough. My point here is that an ECU swap will be working with an '84 carb not the '83. Thanks

I have an '81 4WD M/T 1.8 California model hatch. I removed all the feedback/emmissions stuff from the engine compartment a long time ago. I have an '83 hitachi carb in right now with non-feedback jetting, and I am wondering if I switch out the ECU to one from a non-feedback hatch if it will help mpg's or overall driveability, or even just idle stability. Or should I just unplug the ECU since the non-Cali '81's didn't come with ECU's?

 

If I should swap, will an ECU from an '89 hatch work? Any thoughts on the best (most compatible) year. I have a couple '84 hitachi carbs I am going to rebuild to swap out the '83 also. The '83 works pretty good (25 city/31 hwy grandma style driving), but pretty good isn't good enough. My point here is that an ECU swap will be working with an '84 carb not the '83. Thanks

 

I don't think you quite grasp the situation here - there's no such thing as a "non-feedback ECU". Carbs equipped with ECU's are feedback. Without ECU's are non.

 

So the answer is that you should remove the ECU.

 

GD

OK. I have seen a lot of dialog about feedback vs. non-feedback without a proper definition. If I understand this correctly then non-feedback systems stopped in 1981? Will there be any other effects from removing the ECU?

No - non-feedback continued till the end of carbs in '89 (EA81 hatch).

 

Feedback was always a 2WD, or California model system. 49 states 4WD's never had it.

 

As for a definition - "Feedback" refers to the "feedback loop" programming used by most computer control systems. The 02 sensor continously updates the computer on the mixture - the computer makes adjustments, and the cycle repeats - ad infinitum.

 

Thus you simply remove the ECU, it's associated sensors, valves, and duty solenoids (if you wish - you could just as well leave the junk in there), and install a non-feedback carb with proper routing of the mixture port air supply lines (no duty solenoid controls). That is all that is required to convert an EA81.

 

GD

Alright...I understand what feedback is I just obviously did not know which systems were feedback or non. Thanks for the clarification GD.

 

Not to belabor the topic, but if I understand your two posts correctly, then any 4WD with an ECU is a Califonia model.

 

 

Orginally posted by General Disorder:

Carbs equipped with ECU's are feedback. Without ECU's are non.

 

Feedback was always a 2WD, or California model system. 49 states 4WD's never had it.

Not to belabor the topic, but if I understand your two posts correctly, then any 4WD with an ECU is a Califonia model.

 

Yep - that's the size of it.

 

Barring some type of swappage from a previous owner.

 

GD

That's interesting. Based on what I have encountered in the junkyards here, a lot of Cali. models migrated north. More than I would have guessed anyway. Thanks again for the clarification GD. I have been trying to figure that one out for a while.