Does the 3 Wire feedback carburettor on 1985 Nissan 720 support having an O2 Sensor?

[Doomedwalker]

there is no Sensor or wire from the harness where one would be so i was wondering if its something this truck would of had with only a 3 wire feedback carb?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited May 22 by Doomedwalker

[datzenmike]

The '3 wire' carburetor is not a feedback carburetor. Feedback or ECC carburetors had a round 6 wire plug, an 0² sensor and an ECU to run the carburetor mounted under the driver's seat.

[Doomedwalker]

36 minutes ago, datzenmike said:

The '3 wire' carburetor is not a feedback carburetor. Feedback or ECC carburetors had a round 6 wire plug, an 0² sensor and an ECU to run the carburetor mounted under the driver's seat.

Shoot i thought it was a feedback one, 

Ok,

You would think BC would of required an O2 sensor.

 

Guess ill just get am aftermarket afr gauge and O2 sensor.

[datzenmike]

The ECC carburetor was a California emissions requirement. It was likely used in other states that requires emissions testing. Did we get it in Canada? I think so, possibly, maybe an option. It's a half way between carburetor and EFI. The primary jet is actually a solenoid that opens and closes many times a second to meter fuel. Once warmed up the O² sensor goes into closed loop and adjusts the solenoid to closely maintain a stoichiometric air fuel ratio for low emissions and good mileage. It does not work at idle (obviously) and at full throttle so performance is not affected. Because the solenoid theoretically could cause a severe lean mixture, if there is a failure, the system reverts to a 'limp home' mode and forces an over rich condition to protect the engine. If you had an ECC and your mileage suddenly dropped, this is probably why.  

[Doomedwalker]

1 hour ago, datzenmike said:

The ECC carburetor was a California emissions requirement. It was likely used in other states that requires emissions testing. Did we get it in Canada? I think so, possibly, maybe an option. It's a half way between carburetor and EFI. The primary jet is actually a solenoid that opens and closes many times a second to meter fuel. Once warmed up the O² sensor goes into closed loop and adjusts the solenoid to closely maintain a stoichiometric air fuel ratio for low emissions and good mileage. It does not work at idle (obviously) and at full throttle so performance is not affected. Because the solenoid theoretically could cause a severe lean mixture, if there is a failure, the system reverts to a 'limp home' mode and forces an over rich condition to protect the engine. If you had an ECC and your mileage suddenly dropped, this is probably why.  

 

Yes i got in canada i am from alberta, the engine and transmission are from my uncles old 85 used to be from Chiliwack BC, i have in Alberta.

 

I dont know if it had an ecc, but there was a computer under the drivers seat, its different than the computer that used to be in it from before the manual swap. There is no oem place for a O2 sensor. 

[datzenmike]

I doubt if the engine harness was swapped so probably stock carburetor. 

 

ECC carburetor. Note round connector and 6 wires.

 

 

 

There is a small harness of wires to the solenoid at the front under that light plastic thing...

 

 

Here are the wires involved...

 

[Doomedwalker]

4 hours ago, datzenmike said:

I doubt if the engine harness was swapped so probably stock carburetor. 

 

ECC carburetor. Note round connector and 6 wires.

 

 

 

There is a small harness of wires to the solenoid at the front under that light plastic thing...

 

 

Here are the wires involved...

 

Yeah i think its still stock to the engine, mine only has 3 wires, my other ones that were 84s were only 2 wires.

Edited May 22 by Doomedwalker
spelling

[Doomedwalker]

this is the AFR gauge i am looking at, 

 

https://www.amazon.ca/ABSOPRO-Controller-Colorful-Automotive-Universal/dp/B0F1YNGKKR?ref_=Oct_d_oup_d_9163877011_0&pd_rd_w=RARBQ&content-id=amzn1.sym.b9874f9d-776d-4b73-a4a8-90dec7c3716e&pf_rd_p=b9874f9d-776d-4b73-a4a8-90dec7c3716e&pf_rd_r=PBBYP6XMP6THC06CEQXB&pd_rd_wg=jTxne&pd_rd_r=2f1f45fc-c2fb-4cf7-a371-b12450ec37ec&pd_rd_i=B0F1YNGKKR

[datzenmike]

For under $25? You get what you pay for. Not a wide band so no actual numbers so you don't really know, only if above or below optimum.

 

 

I got an Innovate wide band. Bit pricey, but I was dialing in my R-1 carburetors. Idles 14.7 and cruise at 50 is 14.7 for best mileage. Full throttle is 12.8-13. 

 

https://www.ebay.com/itm/293628123655?

 

[Doomedwalker]

23 minutes ago, datzenmike said:

For under $25? You get what you pay for. Not a wide band so no actual numbers so you don't really know, only if above or below optimum.

 

 

I got an Innovate wide band. Bit pricey, but I was dialing in my R-1 carburetors. Idles 14.7 and cruise at 50 is 14.7 for best mileage. Full throttle is 12.8-13. 

 

https://www.ebay.com/itm/293628123655?

 

 

i cannot afford anything much better, than 25 to 50 bucks where i sit financially, 

https://www.amazon.ca/Shkalacar-Narrowband-Volmeter-Modification-Accessories/dp/B0CND18DC1/ref=zg_bs_g_9163877011_d_sccl_41/139-4532569-6837822?th=1

 

also do you know what turning this with the big spring on it does?
its not the hi idle.

[datzenmike]

Off hand I don't. Possibly for setting the idle speed or fast idle when the choke is on? Can you post a picture from slightly farther back?

[Doomedwalker]

16 minutes ago, datzenmike said:

Off hand I don't. Possibly for setting the idle speed or fast idle when the choke is on? Can you post a picture from slightly farther back?

 

i know its not for the hi idle you have to pull the carb off to adjust it.

[Doomedwalker]

 

[Thomas Perkins]

Also with a 720 with no 02 sensor means your exhaust manifold will not have a hole for it.But if you need a new exhaust manifold,you will have to find a plug for it.I did replace my Exhaust manifold when Nissan had them in stock for 212.I still have dealer Nissan receipt They came with a plug for another hole cause they change to original part to what I bought.I had to pay 7 bucks for the plug.It did not come with it.Dealer had it.

[Doomedwalker]

14 minutes ago, Thomas Perkins said:

Also with a 720 with no 02 sensor means your exhaust manifold will not have a hole for it.But if you need a new exhaust manifold,you will have to find a plug for it.I did replace my Exhaust manifold when Nissan had them in stock for 212.I still have dealer Nissan receipt They came with a plug for another hole cause they change to original part to what I bought.I had to pay 7 bucks for the plug.It did not come with it.Dealer had it.

Yeah i know. I have the exhaust still that came off the 85 i put in my truck, i just didnt put it back in keft my exhaust from the 84 on it. But no holes for O2 on any of the manifolds i have.

[Thomas Perkins]

Here is the part number for the newer exhaust manifold that replaced the original one.14002-14c10.The plug goes in the 02 sensor.Not available any more.The one I have has plugs on some of the holes.

[Doomedwalker]

1 minute ago, Thomas Perkins said:

Here is the part number for the newer exhaust manifold that replaced the original one.14002-14c10.The plug goes in the 02 sensor.Not available any more.The one I have has plugs on some of the holes.

Yeah that would be good to get if i got a AFR gauge.

[Thomas Perkins]

Just now, Doomedwalker said:

Yeah i know. I have the exhaust still that came off the 85 i put in my truck, i just didnt put it back in keft my exhaust from the 84 on it. But no holes for O2 on any of the manifolds i have.

Your's is not made to use the 02 sensor.Mine is still in the exhaust and I got rid of my cat.Just going to leave it be.Not hurting anything.

[Thomas Perkins]

Just now, Doomedwalker said:

Yeah that would be good to get if i got a AFR gauge.

What is that?

[Doomedwalker]

1 hour ago, Thomas Perkins said:

What is that?

Air fuel ratio.

[datzenmike]

Left is stock exhaust. Right has the O² sensor with green wire in it.

 

 

Three wires... choke and power and ground for the idle cut solenoid.

 

[Thomas Perkins]

Get rid of that  Dinosaur  and get a Weber?I think Fred Flintstone got a Weber.Never Seen Barney drive.Did you?

[Doomedwalker]

1 hour ago, Thomas Perkins said:

Get rid of that  Dinosaur  and get a Weber?I think Fred Flintstone got a Weber.Never Seen Barney drive.Did you?

 

"Checks bank account" 0.06cents nope i don't think i will be getting a weber anytime soon.

[Doomedwalker]

2 hours ago, datzenmike said:

Left is stock exhaust. Right has the O² sensor with green wire in it.

 

 

Three wires... choke and power and ground for the idle cut solenoid.

 

yeah i got the first one. 

 

what does the part i circled in blue do?

[Doomedwalker]