Jump to content

1986 505 N9TE Turbo Oxygen O2 sensor


Recommended Posts

You can 'read" the O2 sensor from the wire emanating from the right fender not quite to the air filter hosing (wire 22, female connector going nowhere). The book says to:

Disconnect the wires from the 60 degree C thermocontact and plug them together.

Plug PCV hose and leave fitting open to the atmosphere,

Check voltage to be 7.2 volts +/- 0.2 volts.

Engine speed 910 rpm.

When measuring, the meter will dance around as it samples the air flow mixture.

Whenever I was in doubt, I replaced it (one from an 88 Ford Bronco works swimmingly, just need to modify the pigtail). It is a lot cheaper than an OEM that does the same thing.

-Bill

Link to comment
Share on other sites

Hi Bill,

Thanks for the detailed instructions. I assume then the O2 sensor is working its an SG36 Standard Motors 3 wire only 9 months old. The values do change but no matter how much we try we can't get the value to go below 8.55.

Before this whole thing started I remember the idle air screw was half way in and lead 22 read 7.6V

Now, the idle air screw is almost all the way out. I tested the AFM according to the book and it seemed like it passed.

Bad primer fuel pump replaced, main fuel pump and filter replaced, leaking Fuel Pressure Regulator replaced, bad Aux Air Device replaced, O2 sensor replaced, Tachymetric relay replaced, bad NTC engine coolant sensor replaced.

I haven't tested the Throttle Position Sensor yet. Engine runs very well now but is still running too rich. Any other tips?

Cheers,

GS

Link to comment
Share on other sites

Have you measured your fuel pressures at the rail? How many miles on the injectors? Injectors would likely be the next thing I looked at because if they're not spraying atomized fuel well then you might be running rich. Spark plug condition? Seeing what colour the plugs are should be a help as well.

I do have to say that I'm not a big fan of jobber O2 sensors. I'd prefer to use OEM quality Bosch just to be on the safe side because if the plugs look good it could just be the sensor isn't giving the proper voltage range - but that's an outside guess. Making sure it's running rich with other symptoms like excessive fuel consumption, exhaust that makes your eyes burn / water, and black soot on the plugs will back up running rich.

Adjusting the TPS, and ensuring the idle switch is functional will also ensure the car is running 100%. I was blown away how much nice my 505 turbo ran with the TPS dialed in to the exact target voltage.

If you do narrow it down to the O2 sensor and you're handy with wiring - I'd seriously look at using a heated 4 wire O2 sensor instead. Google retrofitting a 4 wire O2 sensor as there's lots of write ups on how to do it. I will be doing this to my 86' GL-Turbo when I resurrect her this summer.

Rabin

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...