I have a vacuum tube connected to that nipple, just saying.

 

Okay, so this morning I got a better start out of her, but still rough. It's just been bothersome because once warmed up, I feel like she is running better than ever.


One odd thing I noticed though this morning was when the ignition was clicked to acc, the intake temp reading was -40f. After cranking the car, the temp adjusted to what looked normal.


My plan at the moment is to put in an order on AB for a intake temp sensor and flywheel grommet. Then plan to do an induction cleaning and all of the breather hoses, tbi, and pretty much anything else connected.


I also still need to find an actual plug for the plenum nipple. Maybe AB can throw one in my order.


Again, I will update as I learn more.

 

Where does the other end connect?

 

Also, can someone tell me if this part: [Linked Wrong Intake Temp Sensor] is the intake temp sensor I need?

 

If you have secondary air injection, there is a tube that runs from the SAI to that nipple. If you do not have SAI, the should just be a cover. Discorey, do you have SAI? I don't think you do based on this thread. If you don't then that is wrong sensor you posted the link to. The photo that Backin a 88 posted is showing no secondary air hose, just a cover. If your setup is the same as his, you don't have secondary air and that would be the wrong temp sensor for sure.
Take a look at what SAI looks like:
http://www.roverlandparts.com/2ndair.aspx

This might help you sort things out better.

 

I do not have SAI.

I noticed after you asked whether or not I had SAI that I linked the wrong sensor.

I called AB, and asked if they have the one I need in stock. Brian that I spoke with said they don't get many asks about that sensor, so he asked what I had diagnosed that led me to that. So, I went through everything I'm currently dealing with, and he thinks it could be the IACV. So, now, I'm on the lookout for a new IACV.

I'm hoping to try one if I can find it at a Pick N Pull before buying a brand new one to see if I notice any differences.

I found a new Bosch OEM IACV on amazon for $174..

Is there a chance I've got a plenum for a SAI D2, or did all D2 plenums come with this nipple and some were capped?

Thanks for everyone's help. I will continue to update once I get the proper diagnosis and fix.

 

I had trouble with the IACV as well. I'm not saying this is a good idea but it seemed to help. I bought two cans of brake part cleaner and a 1 quart paint can. I very carfeully sprayed the parts cleaner into the can. It is a common practice for scale modelers who want to use their own airbrush instead of the spray can. I sprayed enough into the can that I could immerse the openings of the IACV and let it soak. I would pull it out, clean it and repeat the process a number of times. It really got the carbon buildup out and seemed to help the performance. I will grant you that I had done a bunch of other things like replacing the vacuum lines and PCV purge valve, but it seemed to make a difference. As you seem ready to go the PNP or buy one route, how much damage could you do? I make no warranties or guarentees.

 

Seafoam is really good at breaking down carbon deposits. I use it to clean throttle plates on newer cars that have coatings around where the plate seals on the intake. It breaks down the carbon, but doesn't damage the coating. I would think it would be safe for use on the IAC.
As long as your temp is normal when the engine starts up, I wouldn't worry about the IAT sensor. The IAC may not be opening all the way on cold starts. It should flare on startup and then slowly come down to a normal idle.

 

So, I'm cleaning the IACV now. Still getting some tiny little bits of carbon coming out. Alternating between soaking in seafoam and spraying out with starting fluid.

The flap inside the IACV moves freely if I depress it with a screwdriver and goes back into place when I remove the screw driver, but it's still sort of floppy in the housing. I hope that is normal.

 

That's probably okay. As long as it is capable of opening all the way with no obstructions. If there was enough of a buildup behind it that it couldn't open up all the way. You would almost certainly have problems on startup. Especially cold starts.
I hope that's all it is. It's always nice when you can fix things without spending money on parts.