What sensors does an 84 ea81 have?

[hiltz2o]

Does anyone have a list of sensors on an 84 ea81?

 

Thanks

[mountaingoatgruff]

when mine had a hitachi 2bbl i think the only "sensor" it had was the temp sensor for the gauge that's mounted in the intake manifold.

 

other than that there's the oil pressure sending unit for the gauge (mounted on bottom of oil pump, if you have an idiot light its just a switch on the side) and temp switch for rad fan (mounted in rad) but those aren't actually sensors.

 

its a carb'ed engine...means there's no sensors needed.

[hiltz2o]

Apparently I have a feedback carb and I am looking for what items impact the feedback on it. I suppose the O2 sensor is one of them

[mountaingoatgruff]

i glanced over my 84 fsm and it shows that for a 49-state car you'd only have a factory ECC system (eclectronicly controlled carb, or feedback carb) if you've got a 2wd car. hitachi and carter setups use the same sensors, but even then you don't have much:

 

thermosensor (for gauge, mounted in intake)

oxygen sensor (for ecc, in y-pipe of course)

vehicle speed sensor (for ecc, mounted in speedo)

rev sensor (for ecc, wired into coil - not sure where its located)

 

there's some thermal and vacuum switches that are included in the system, the best thing to do is get ahold of a schematic so you can see everything at once. if i had a scanner i could upload those pages, but i don't.

 

do you know if its a hitachi or carter carb? 2wd?

[hiltz2o]

i glanced over my 84 fsm and it shows that for a 49-state car you'd only have a factory ECC system (eclectronicly controlled carb, or feedback carb) if you've got a 2wd car. hitachi and carter setups use the same sensors, but even then you don't have much:

 

thermosensor (for gauge, mounted in intake)

oxygen sensor (for ecc, in y-pipe of course)

vehicle speed sensor (for ecc, mounted in speedo)

rev sensor (for ecc, wired into coil - not sure where its located)

So probably the one that changes how the computer feedbacks to the carb the most is the O2

there's some thermal and vacuum switches that are included in the system, the best thing to do is get ahold of a schematic so you can see everything at once. if i had a scanner i could upload those pages, but i don't.

 

Maybe someone reading this would be kind enough to scan one for me

do you know if its a hitachi or carter carb? 2wd?

I have 2WD but I'm not sure about the hitachi or carter. I thought that only hitachi was available that year.

 

I'm trying to fix a problem with hesitation that comes and goes. The carb has 224+ k miles so it needs a rebuild. I also have the ignition pulse code (Code 14 that year), but I'm not sure how much that has to do with it since it was running for a few days perfectly even with that code on. I think it could be gummed up carb from sitting for years with old gas in it. I've only driven it 155 miles since its been sitting for that long, and it seems like if I spray a ton of carb clear in it and suffocate it sometimes it comes out of the problem for a while and but then returns to the same old stuff. I'm getting a rebuild kit through autozone today but I wanted to know what things could be effecting the feedback so I could replace those too. I don't want to go weber.

[GeneralDisorder]

thermosensor (for gauge, mounted in intake)

oxygen sensor (for ecc, in y-pipe of course)

vehicle speed sensor (for ecc, mounted in speedo)

rev sensor (for ecc, wired into coil - not sure where its located)

 

That's not entirely complete. Here's a full list of the ECU's input's:

 

1. Battery voltage (duh).

2. Ground (duh 2).

3. Speed sensor.

4. O2 sensor.

5. RPM (tach signal, coil negative, ect).

6. Vacuum switch 1 [(0 - 100 mmHg for MT, 0 - 86 mmHg for AT): ON].

7. Vacuum switch 2 [0 - 200mmHg: OFF].

8. Thermo sensor (coolant temp - it's a dual element sensor - one element for the gauge and one for the computer. Different than the non-feedback).

 

And it's output's:

 

1. Kickdown solenoid (AT only).

2. Duty solenoid (slow).

3. Duty solenoid (main).

4. Automatic choke relay.

5. ASV Solenoid valve.

6. EGR solenoid valve (AT only).

 

There's an entire chapter of the FSM dedicated to this - I don't have time to scan it all unfortunately. I sugest you pick up a copy for your own if you intend to work on the feedback system succesfully.

 

GD

[GeneralDisorder]

So probably the one that changes how the computer feedbacks to the carb the most is the O2

 

Not true. You can't say what has the biggest impact without specifying the conditions. The thermosensor (coolant) has a very large impact - for one thing the O2 sensor has NO effect when the engine is cold as it takes several minutes (sometimes 5 or 10) for the sensor to even begin reporting as they are not heated sensors. Durring that time it is ignored by the ECU because no signal from it is present.

 

I have 2WD but I'm not sure about the hitachi or carter. I thought that only hitachi was available that year.

 

C/W's were availible at least till 84. I haven't personally seen a post-EA82 era C/W, but I've seen plenty of 83/84 models.

 

I'm trying to fix a problem with hesitation that comes and goes. The carb has 224+ k miles so it needs a rebuild. I also have the ignition pulse code (Code 14 that year), but I'm not sure how much that has to do with it since it was running for a few days perfectly even with that code on. I think it could be gummed up carb from sitting for years with old gas in it. I've only driven it 155 miles since its been sitting for that long, and it seems like if I spray a ton of carb clear in it and suffocate it sometimes it comes out of the problem for a while and but then returns to the same old stuff. I'm getting a rebuild kit through autozone today but I wanted to know what things could be effecting the feedback so I could replace those too. I don't want to go weber.

 

Well - good luck with that. As I have said you'll spend just as much money screwing with that feedback system as you would buying a nice shiny Weber. And you'll get less power, worse fuel economy, and you'll still have an old, crappy carb. Not to mention you'll be dirty, high from the fumes, and will never get back the time you wasted. At least with a Weber you can yard it off and sell it on ebay for 3/4ths of what you paid for it when you get rid of the car....

 

GD