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Some mystery on my 90 Talon Tsi AWD

07-07-2009, 08:28 PM
I have a few problems with my 90' Talon Tsi AWD.

First off. I changed the gaskets on the throttle body and the throttle body elbo the other day and when I went for a drive to make sure everything was working, I noticed my engine temp gauge stopped working. I started looking around the engine bay for clues. And I found the following wire (See picture below) it comes across the plastic cover across the front of the intake manifold. I have asked all my friends either what it is or where it is suppose to go, but no-one knows. The wire where it comes out is rather short so it's gotta plug in somewhere close. If anyone knows please respond. I'm not sure if it has anything to do with my temp gauge or not, because my hayne's doesen't get that indepth. But heres the pic.

The next problem I have is I'm trying to hook the sensor wire from my A/F gauge. I know the big debate over A/F gauge, but I got it cheap and I needed to fill the hole on my pod. But here's my prob. I am trying to tap into the o2 test port on the passenger side. But once again my manual doesen't cover the test port. So I have two questions. Can someone confirm this is the right port. I think it is because it's the only one that doesen't connect to anything. And the second question is I have used a volt meter to try to determin which one is the actual signal wire. If anyone knows please feel free to say which one it is. The 3 wires are (Left to right - black with blue strip, the middle one is blue with white strip, and the one on the right is green) Here is the pictures.

Thank you for any help.

07-07-2009, 10:01 PM
The plug in the first picture isn't ringing any bells for me. Your temp gauge though is based off the water temp actually. The sensor for that should be in the bottom of your thermostat housing somewhere. The wire probably just came unplugged there because it's one of those slide on plugs.

07-07-2009, 10:02 PM
Cant help you with the temp sensor but your o2 sensor gives out a signal of 0-1v. At idle you should get a reading bouncing back between .2 and .8v or so. It would probably be easier to hook up your gauge at the ECU. You should be able to find a pinout online somewhere that tells you which wire is the o2 sensor. Make sure to confirm this with your voltmeter

07-07-2009, 10:06 PM
Yea, it's number 4 pin on the ecu. I was just trying to avoid taking out the ecu.

07-08-2009, 07:50 AM
I don't think you're far enough up in the harness. Pretty sure the connector is a single wire per the VFAQ.

Oh, and don't install the thing. ;)

07-08-2009, 04:51 PM
Hey man thanks for the heads up. I read the vfaq on this and the pictures there were for an eclipse of a different year. So when I found my plug I thought it was the right one, but this morning I did what you said and sure enough I found the right one, it was hidden way in the back. So thanks man... Now I can enjoy the light circus I think i'm gonna change it for an egt. I just gotta pay some other stuff off befor I drop even more money in the car. I think I'm at about 1200 this month alone...

07-09-2009, 06:52 AM
Skip the EGT. For what you can get for a used AF on Ebay, plus the cost of an EGT gauge, you'll be right there in WB02 territory. :)

07-09-2009, 08:36 AM
Skip the EGT. For what you can get for a used AF on Ebay, plus the cost of an EGT gauge, you'll be right there in WB02 territory. :)

Agreed. Widebands are much better if you plan on modding/tuning. You can find AEM UEGO WBO2 for less than $200 these days. Not a bad price and totally worth it. I run both and pay more way more attention to the WB.

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