Identifying parts and pieces 258

[Joseph.smith54]

This thread may have been started before but I need some knowledge as to where some parts connect to and what some are.

First off is my carter yfa carb. I know one inlet goes to my fuel pump/ filter and not sure about the other. Where does it go?

Next, this little valve on the lower driver side of my engine. What is it and what connects to it?

Last one so far, what is the lever on the bottom rear of my exhaust manifold for?

 

[greg92jeepxj]

Although I am no pro and welcome the advice and help of anyone who has a 258 of your year with the same emmissions and fuel system , I'll post what I know. In your first photo , the open tube on the carburetor is the port that goes to the vapor line from the charcoal canister line out to feed vapor into the carb to burn off as fuel in the engine. Fuel systems from the gas cap forward are not vented and the vapor must be relieved from the system to avoid excess pressure . Kind of like the human body. If there is no canister , close it off. The spark plug being used as a plug to close off a vacuum leak , I believe that vacuum source should be used for a power brake booster if your jeep has power brakes. If not , I see why it's closed off. I think I also see a speedo connection coming from the tunnel forward to the engine side of the firewall .
Photo #2 ; I see an EGR valve which are connected to exhaust manifolds on in-line engines .
behind it , in the exhaust manifold to the exhaust pipe is a thermostatic valve that closes when engine is cold and opens when warm. This is to aid engine warm up . Make certain they move freely (penetrating oil) or if stuck closed , will cause poor power , stalling and backfiring due to the engine unable to expel exhaust gas pressures . I think they were called a heat stove or heat riser valve ?
They also vented warmed air to the air cleaner snorkel to aid engine warm up through carb air intake . Third photo ; I am looking at a thermal vacuum switch or CTO which will use vacuum from a vacuum source ( carburetor vacuum port ) to operate the EGR valve . The EGR valve is suppose to open only above idle and only on a warm engine. That is why a (TVS) thermal vacuum switch or CTO ( coolant temp override) is used and must be ported to a vacuum source above the throttle blades on the carburetor. A port on the float bowl for secondary vacuum and not primary vacuum during idle. The two bosses to the left of the switch are closed off ports ( with pipe plugs ) for bleeding off engine coolant or threaded optional motor mount locations ? Can't clearly see them well .
hope this explanation helps and may you be successful at getting this jeep running soonest ! Greg

P.S. - forgot to mention the pipe coming off the choke assembly on rear of carb , it is to supply hot air to the choke. It will got hot air from a heat source from the exhaust. There are electric chokes and hot air . Yours is apparently a hot air choke. I don't think a line would tap into the exhaust directly or carbon will build up inside it , but usually hot air rises inside the tube to the choke assembly .

 

[Joseph.smith54]

Thanks Greg.
I figured a Haynes or Chilton manual would be able to show me but can't seem to find my answers in there. Since a lot of these ports weren't connected when I bought the jeep, I'm finding it a little difficult to find where they go. As well as some of the electrical but I think I've about got it figured out.

 

[greg92jeepxj]

Thanks Greg. I figured a Haynes or Chilton manual would be able to show me but can't seem to find my answers in there. Since a lot of these ports weren't connected when I bought the jeep, I'm finding it a little difficult to find where they go. As well as some of the electrical but I think I've about got it figured out.

Your most welcome . I think you ought to be alright with those connections , I'll bet you cannot wait to get it fired up ! I know you must hate to have to correct someone else's handiwork but its kind of rewarding when you get it working and fixed something someone else gave up on . A little at a time , I know you'll get it. Between your two hands and Jeepz.com , it will come together soonest . Greg

 

[Joseph.smith54]

Hey Greg. Is anything supposed to be connected to the thermostatic valve?

 

[greg92jeepxj]

Hey Greg. Is anything supposed to be connected to the thermostatic valve?

I'm sorry joe , but by the thermostatic valve , are you referring to the one on the carburetor or the heat riser valve on the exhaust ? The heat riser should just be a thermostatic spring that opens when warm and the choke thermostat on the carburetor is either electric , hot air or a thermos tic spring mounted on the intake manifold . If you mean the one on the engine block , I will have to reference that but I'm pretty sure that was to control the EGR valve . A vacuum line from vacuum source in intake manifold and a line to the EGR valve . The thermostatic valve won't let the EGR receive vacuum until the engine is warm so to prevent an over rich condition when not up to operating temperature . Hope this helps joe .

 

[greg92jeepxj]

I'm sorry joe , but by the thermostatic valve , are you referring to the one on the carburetor or the heat riser valve on the exhaust ? The heat riser should just be a thermostatic spring that opens when warm and the choke thermostat on the carburetor is either electric , hot air or a thermos tic spring mounted on the intake manifold . If you mean the one on the engine block , I will have to reference that but I'm pretty sure that was to control the EGR valve . A vacuum line from vacuum source in intake manifold and a line to the EGR valve . The thermostatic valve won't let the EGR receive vacuum until the engine is warm so to prevent an over rich condition when not up to operating temperature . Hope this helps joe .

P.S.- if you still got the post from September on this thread , I just found where I wrote that the thermostatic valve on the engine block is a CTO ( coolant temperature override ) which is used for the EGR valve.