Use a thick flat head screwdriver and a hammer. Don't be scared to get rough with this just make sure you hit on the outside rim of the plug with the tip parallel with the rim not perpendicular.
Wedge the throttle open. I think I stuck a screwdriver in the linkage. The little spout facing down from the top is where exhaust gasses come into the intake from the egr valve.
Cut a piece of cardboard so you can stick in into the throttle body in order to catch carbon.
Stick a screwdriver in the hole like this and wiggle it like crazy. You may even need to use a hammer to open a path through in between wiggling.
This is what it should look like after sticking the screwdriver through before wiggling it around.
Carbon will start to fall.
By the end of this process you may have this much or more. It's better to pull out smaller loads than to try to pull out a giant load, like I did, chancing dropping this crud down the intake manifold.
There is a tube that runs down the top of the manifold.
On the 85 manifold there is a 10mm female allen plug on the back side, facing the firewall & adjacent to the EGR valve, but on the 84 there is only an EGR valve.
This is the 84 manifold:
This is the 85 manifold. Notice the stud which the EGR bolts to. It is adjacent to the plug and facing the vavle cover not the firewall.
This is the light you can see once you pierce through the clogged carbon. A straw works well to remove the carbon. You have to repeatedly stick the straw in through the back and then blow the carbon out. Eventually you'll get it all.
Removing the EGR valve requires removing two or three small 10 or 12mm nuts and loosening a rather large flange nut which connects the EGR to a S-bent pipe that bends around the rear of the engine. It's WAY easier
to remove the EGR if you unbolt the back side of the S-bent pipe. To do this you must remove 2 bolts. They're a PITA to get to but it's possible. I had to lay on the engine and put my arms around the exhaust side and through the back of the spark plug valley.
Loosening the Flange nut:
Back behind here and to the left is the picture under this one:
The bolts in the center facing right and the bolts you want to get. I used all my 3/8" extentions with the ratchet over near the EGR to get to these bolts.
My S-bent pipe was very clear of carbon. I didn't need to clean it but getting off the EGR was not happening without pulling it off too.
Once the EGR is off clean out the inside of it. I used a pick to clean it. Take your time so you don't have to take it off again. I made sure all the carbon and gunk was cleaned out of the EGR as best as I could. I also sucked through a vacuum hose to the top port to see if the EGR would work. You can hear it move as you suck and when you release the vacuum it 'pops' back.
Next I removed the lid of the transducer. There is a filter in there. Mine was very black. There are cotton facial cleaning products that work excellent for a filter replacement. If you can get the 2" circular ones those work great. The square ones work just as good. After you're done cleaning the transducer stuff 2 or 3 of them in there and pop the lid back on. I stuck the pick in every hole possible. If you shake the transducer it seems to loosen carbon up and then if you stick the pick into the holes you can further break up the carbon. Repeat this process until carbon doesn't come out any more when you shake it. Stick the pick up the bottom port to get out what you can too. It was full of water and gunk for me.
The bottom port:
These tubes connect the EGR and Transducer. Clean them out
Gently start the plug back into place with a hammer. GENTLY!
Use a socket that matches the diameter of the plug to finish tapping the plug into place. You want about 1mm of the sidewall to show above the plug.
Wedge the throttle open. I think I stuck a screwdriver in the linkage. The little spout facing down from the top is where exhaust gasses come into the intake from the egr valve.
Cut a piece of cardboard so you can stick in into the throttle body in order to catch carbon.
Stick a screwdriver in the hole like this and wiggle it like crazy. You may even need to use a hammer to open a path through in between wiggling.
This is what it should look like after sticking the screwdriver through before wiggling it around.
Carbon will start to fall.
By the end of this process you may have this much or more. It's better to pull out smaller loads than to try to pull out a giant load, like I did, chancing dropping this crud down the intake manifold.
There is a tube that runs down the top of the manifold.
On the 85 manifold there is a 10mm female allen plug on the back side, facing the firewall & adjacent to the EGR valve, but on the 84 there is only an EGR valve.
This is the 84 manifold:
This is the 85 manifold. Notice the stud which the EGR bolts to. It is adjacent to the plug and facing the vavle cover not the firewall.
This is the light you can see once you pierce through the clogged carbon. A straw works well to remove the carbon. You have to repeatedly stick the straw in through the back and then blow the carbon out. Eventually you'll get it all.
Removing the EGR valve requires removing two or three small 10 or 12mm nuts and loosening a rather large flange nut which connects the EGR to a S-bent pipe that bends around the rear of the engine. It's WAY easier
to remove the EGR if you unbolt the back side of the S-bent pipe. To do this you must remove 2 bolts. They're a PITA to get to but it's possible. I had to lay on the engine and put my arms around the exhaust side and through the back of the spark plug valley.
Loosening the Flange nut:
Back behind here and to the left is the picture under this one:
The bolts in the center facing right and the bolts you want to get. I used all my 3/8" extentions with the ratchet over near the EGR to get to these bolts.
My S-bent pipe was very clear of carbon. I didn't need to clean it but getting off the EGR was not happening without pulling it off too.
Once the EGR is off clean out the inside of it. I used a pick to clean it. Take your time so you don't have to take it off again. I made sure all the carbon and gunk was cleaned out of the EGR as best as I could. I also sucked through a vacuum hose to the top port to see if the EGR would work. You can hear it move as you suck and when you release the vacuum it 'pops' back.
Next I removed the lid of the transducer. There is a filter in there. Mine was very black. There are cotton facial cleaning products that work excellent for a filter replacement. If you can get the 2" circular ones those work great. The square ones work just as good. After you're done cleaning the transducer stuff 2 or 3 of them in there and pop the lid back on. I stuck the pick in every hole possible. If you shake the transducer it seems to loosen carbon up and then if you stick the pick into the holes you can further break up the carbon. Repeat this process until carbon doesn't come out any more when you shake it. Stick the pick up the bottom port to get out what you can too. It was full of water and gunk for me.
The bottom port:
These tubes connect the EGR and Transducer. Clean them out
Gently start the plug back into place with a hammer. GENTLY!
Use a socket that matches the diameter of the plug to finish tapping the plug into place. You want about 1mm of the sidewall to show above the plug.