Where is it?

[Idaho eagle]

Hi everyone, my 81 Mountain Eaglet with the 2.5L engine appears to be missing the spark advance CTO.  Where is it supposed to be located? 
I do know where the EGR CTO is.  Also, I do know where the TVS for the EGR is.

The vacuum diagrams in the
 Chilton's manual are clear enough.   (1981, 2.5L, iron Duke, manual transmission, non AC)

I had expected to see this in the intake manifold but could not find it. Could it be in the block somewhere?  Anyway, I haven't been able to find it.

[Idaho eagle]

Found it!    it looks like I had the EGR CTO and the spark advance CTO confused. The spark advance CTO is located next to the thermostat and has three ports. 

" The EGR CTO valve (fig. 1J-119) is located in the coolant passage at the right rear side of the cylinder head on the four cylinder engine...".  1981 Technical Service Manual page 1J60.         Since all that's left is a melted blob of plastic and rubber, and since I was looking on the intake manifold, i had completely missed it.  Next is to call a friend in Illinois who should be able to get a new CTO for me.

[Idaho eagle]

Hi again,. I found some part numbers to share.  And since I do not have permission to add to or change any of the eaglepedia, and since this concerns the EGR CTO, then I'll post the information here.   Dear moderator, you may want to move this post, or place a copy of it to the part numbers section. Thanks.

PART Numbers for EGR CTO:
1981, American Motors, Eagle, 2.5L, Manual Transmission, without Air Conditioning

Group 4.704-1 SWITCH, Vacuum Ported

          79       Four.                          322-8288
         79-82  Six.                            322-5912
         79-82  Six.                            322-8288

You can get this through Standard Engine Management,  a wholesale/ jobber/ distributor. Their part number is  PVS71.   The description lists: 3/8"-18, temp 117 degrees F., AMC 322 5912,  AMC 322 8288, and several Pontiac numbers.

I went to O'Reilly's to cross reference and get a price comparison.  They  have part number EC920  from manufacturer BWD.

This 'switch' sells for about $22.

Now that I have the EGR CTO  (notice how the name changes from one manufacturer, retailer, parts book, or service manual to another- Switch, Vacuum Ported) ordered, I need to remove the intake manifold so as to have room to turn a wrench..  while I have that off I'll set the engine at TDC and adjust the distributor to be able to hook up the vacuum advance hose.   

A tip for anyone replacing vacuum hoses ( or even heater hoses, etc.) Is to mark the new hoses with a drop of white paint to indicate to myself that that is a hose that I have replaced.  I use a paint pen that I got from Walmart.  I'll even put a drop of paint on hose clamps, power steering  hoses, and so on to indicate items that have been replaced.

[amcfool1]

good job man, and good luck, gz

[mudkicker715]

I will see what i can do.

[Idaho eagle]

The PVS71  is 3/8 inch pipe thread and the part out of the head is 1/2 inch pipe thread. 
Also the ports are bigger.     Since this is nos and is not being manufactured now, then I'll have to work around.    If I take a pipe reducer and cut off the hex and some of the threads then that would allow the sensor part to be in the coolant.  There are nipples available that allow one to connect different size hoses together. They are a connector that is a double hose barb. Can get from Harbor Freight.

[AMC of Houston]

You have the wrong part number for the EGR CTO.  Your P/N is for the "Audi" 4-cylinder from 1979.   The correct AMC P/N for the 1981 "GM" engine CTO is 8132343.   Hope you can cross that part number to something.