Riddle me this? Parts ?????

[C10Silverado79]

A couple more 'what is this?' questions.

What is the canister with the vacuum line that is above the manifold. It had a hard line out the back that runs down toward the transmission. The vacuum line connects to the vacuum tree on top of the thermostat.


There is a cable attached to the bottom of the throttle linkage that also looks like it runs down toward the transmission. I have a 3 speed trans but I don't know what model. There is also a vacuum line off the manifold port and looks like it connects to the rear of the transmission. I thought this was the 'kick down' line but now I'm not sure.


I also noticed that when I have the gas pedal to the floor, the throttle is not completely open. Is there any way to adjust this?


TIA

[benoit454]

well the long slot cable next to the throttle one looks like a kickdown cable, but then again on bottom on the bracket looks like the cable end is missing, that would be the kickdown since it's on bottom. The long slot cable looks like it goes to a round vac. pod which would be cruise control, and looks to be behind the bracket. The bottom one though as I said looks broke or cut off any better pics of the one in question? If you have 3 cables going to the carb, you got one throttle, one cruise, one kickdown. A th400 is a 3 speed but it has a switch by the gas pedal so no kickdown cable, but both use a vac. line going to the vac. modulator, so yea you should have a vac. line going to the trans. back right side/pass. side.

As for the can no idea, I was thinking the efe but that's in the exhaust manifold and not going towards the trans. nor have I seen one with a can period lol.

well after another look maybe that cable aint broke I can barely see it. it's got a long slot and is in behind there in the back that's the kickdown and means you have a th350.

As for throttle looks like it should be where the other cable is, I don't think it needs that long stud sticking out there but maybe. As for it not going all the way back with the cable something may be worn out like the cable itself or something in the throttle pedal. I don't think there's any adjustment to it.

[54Caddy]

the canister is vacuum operated to open the exhaust flap. Have on on my truck.

[C10Silverado79]

Originally Posted by benoit454

well after another look maybe that cable aint broke I can barely see it. it's got a long slot and is in behind there in the back that's the kickdown and means you have a th350.

The bottom cable is not broke, just hard to get a picture of. It does have a long slot and I always thought the trans was a th350 so that makes sense. I just thought the vac line to the trans was the 'kick down'. What does the vac line to the trans do then? It does run down the right side and connect at the rear of the trans.

[C10Silverado79]

Originally Posted by 54Caddy

the canister is vacuum operated to open the exhaust flap. Have on on my truck.

What is the exhaust flap for or do?

[79gmcc15]

Originally Posted by C10Silverado79

What is the exhaust flap for or do?

It's supposed to help the motor warm up quicker. Its basically worthless, but if everything works, leave it. Mine is broken and makes quite a noise, ticking.

[1LowToy]

The vacuum servo is for the exhaust heat riser. It blocks the exhaust from the exhaust manifold to make the hot exhaust pass through the intake to the other side when the engine is cold. This in turn warms up underneath the carburator to vaporize the gasses coming from the carburator.

For your full throttle press accellerator to the floor (engine off of course). Then check to see if carburator is actually opening the secondaries. The flaps on top of the carburator will not open but the ones below on the base plate should. It could be just a cable adjustment needed. I did find on mine that the transmission throttle pressure cable was set too tight. It went into passing gear real easy but it was also stopping the throttle cable from getting the carburator to open up the secondary flaps.

The vacuum line going to the back of the trans is likely to the vacuum modulator. This is for shift quality or in some cases is for the transmission kick down or passing gear.

Hope this helps

[benoit454]

it's not likely if it goes to the back of the trans. IT IS the vacuum modulator, and it controls the part throttle or wide open throttle shift points, I forget which, I know if you have it unplugged it's supposed to take forever to shift gears and when it does it shifts hard. it also helps the transmission to know what kind of vacuum the engine has like being under load and what not.

The actual passing gear/kickdown is done by the cable.

[54Caddy]

the exhaust thing does work works fine on my truck. if you decide not to run the cruise control ill take the rod for it ahaha, cant find one at all for my truck

[bigwheel15]

Originally Posted by 54Caddy

the exhaust thing does work works fine on my truck. if you decide not to run the cruise control ill take the rod for it ahaha, cant find one at all for my truck

Which rod is it? Im taking off my cruise and wouldnt mind sending the part your way(as long as the part is actually there lol).

[79gmcc15]

Ya'll have to be paid members to sell something on this site or post a Want To Buy*wtb*.

[benoit454]

yea you'd better watch I got a freakin violation for doing the same things, guy had a cowl hood he wanted a stock one and I offered to trade and got a posting violation which IMO was BS, so be on the lookout you guys will probably get one too, if not then I don't think it's right since I got one before for the same stuff.

[KQQL IT]

no one said you cant give parts away tho...

[motornut]

The heat riser valve ??,i have bent back the nib for it to stay open (nib on the pipe)also you can tack it open(reqires wielder)... drill hole in pipe close to valve, use coat hanger to push in, bending it up towards it, you should feel the valve open up,to go past it(be sure your not closing it),tack it,out on sides if no nib,wield drill hole closed


the cruise control rod is the long skinny with the slot ,on the rod that sticks out,should unscrew,you may have some air leaks around the connections ,on ones i've seen the big vac line cracks low around the connection

[C10Silverado79]

Now that I know what to look for, I found some info in my Haynes manual. The manual says the default position is open (out to exhaust) and only redirected when the motor is cold from one of the temp-sensor vac ports. I still need to check if it's working. Need to check the EGR valve too.

[motornut]

it should move freely,(if not seized)as it works by vac

[benoit454]

Well when I got my citation or warning or whatever we weren't discussing money either, straight up trade, my hood for his hood and got in trouble over it, posting violation.