1964 FI Choke Issue

[Patrick C.]

Re: 1964 FI Choke Issue

You are missing a piece of the puzzle. The tube you have in mind runs from the manifold to the choke housing. That manifold hole has an additional tube inserted going all the way through the manifold to allow fresh air to be heated. Not supposed to pass exhaust gas. But, when it rusts through, it does. Could be your issue.

I got it now. Looks like I will need to replace the tube that goes through the exhaust manifold. Does someome make this tube? Is it replaceable with the manifold in place? How do you pull the rusted unit out of the manifold? Damn should have replaced this when the manifold was off��

[Patrick C.]

Re: 1964 FI Choke Issue

Thanks Joel, I got the pictures of your manifold with the tube.

[Duke W.]

Re: 1964 FI Choke Issue

The tube in the manifold, which is stainless,
-Dan-

Maybe repros are stainless, but the OE interior exhaust manifold tube was plain carbon steel. That's why they eventually rust out and allow exhaust gases to mess up the choke system.

Duke

[Patrick C.]

Re: 1964 FI Choke Issue

Looks like I will be pulling the exhaust manifold and installing the tube.

[John D.]

Re: 1964 FI Choke Issue

Patrick, As soon as I saw your post and pics I knew immediately it was your exhaust manifold heat tube. You haven't lived until you restored a midyear FI unit and 6 weeks later the owner brings it to me at a show because choke doesn't work. So I removed the choke cover and the entire choke housing was packed full of soot!!! Meanwhile I was in my vendor trailer with nothing to work with except zippo lighter fluid, paper towels and Q-tubes. I preach to all to replace the exhaust manifold heat tube. I tell them to take it to their local machine shop etc to have the job done
Repros readily available.
Choke shaft is sticking you say. It has to be 100 free with no binding. Some thing the choke cover spring will help a sticking choke shaft. Not really. Meanwhile Scott is a very good FI fellow and my friend and customer for many years. He will handle it for you.

Dead give a way to your rusted out exhaust manifold tube is the condition of your chrome choke tube being black at the bottom!!!! John

[Dan D.]

Re: 1964 FI Choke Issue

My repro is definitely stainless Duke. That is the first thing I checked.

-Dan-

[Patrick C.]

Re: 1964 FI Choke Issue

My repro is definitely stainless Duke. That is the first thing I checked.

-Dan-

Dan

Im struggling to find a SS tube. I only want to do this once. Would you let me know where your SS tube came from? If you do not want to mention a supplier just PM me.

[Patrick C.]

Re: 1964 FI Choke Issue

Patrick, As soon as I saw your post and pics I knew immediately it was your exhaust manifold heat tube. You haven't lived until you restored a midyear FI unit and 6 weeks later the owner brings it to me at a show because choke doesn't work. So I removed the choke cover and the entire choke housing was packed full of soot!!! Meanwhile I was in my vendor trailer with nothing to work with except zippo lighter fluid, paper towels and Q-tubes. I preach to all to replace the exhaust manifold heat tube. I tell them to take it to their local machine shop etc to have the job done
Repros readily available.
Choke shaft is sticking you say. It has to be 100 free with no binding. Some thing the choke cover spring will help a sticking choke shaft. Not really. Meanwhile Scott is a very good FI fellow and my friend and customer for many years. He will handle it for you.

Dead give a way to your rusted out exhaust manifold tube is the condition of your chrome choke tube being black at the bottom!!!! John

Thanks John,

You nailed the problem. I wish this would have been addressed when I had the engine out. Luckily it did not go on too long. I can clean up the choke and butterfly shaft and get it back together in the next month.

[Paul Y.]

Re: 1964 FI Choke Issue

Bii

Pat,
The hot air tube that goes through the exhaust manifold then into the choke housing is probably rusted through allowing exhaust gas into the choke. Also for local help call Scott Pfuehler (pronounced Fuller) at (918) 437-5292. Tell Scott I said "Howdy! Bill

Bill, I think you are right on with that assessment. Paul

[Paul Y.]

Re: 1964 FI Choke Issue

Pat, I use fine steel wool to polish the butterfly shaft. I am careful about what I put on the choke and piston to lubricate. I like to use a graphite bases lubricant or Teflon based. I don't want it to attract too much dust or dirt.

[Duke W.]

Re: 1964 FI Choke Issue

Dry graphite is the best choice for the choke vacuum break piston and bore. Any petroleum based product will trap dirt and foul the works. Lok-Eze is a good choice. It's spherical graphite in a petroleum solvent, which evaporates leaving the dry graphite behind.Duke

[Patrick C.]

Re: 1964 FI Choke Issue

Dry graphite is the best choice for the choke vacuum break piston and bore. Any petroleum based product will trap dirt and foul the works. Lok-Eze is a good choice. It's spherical graphite in a petroleum solvent, which evaporates leaving the dry graphite behind.Duke

Thanks Duke

The choke worled great when I first put it together so adding some Lok-Eze will get it back to where it was. Just pulling the manifold will be the pain. I could just kick myself over this oversight.

[Dan D.]

Re: 1964 FI Choke Issue

Pat,

I bought the choke stuff 10 years ago from Corvette Central. I just checked their website and they are still available under the same P/Ns that I bought them under. Looks like prices have gone up about 10%, which isn't bad for 10 years.

You haven't indicated if you have the tube assembly from the bottom of the manifold to the air filter adapter, so I have included it here.

351270 Air filter tube to air filter adapter $34.00

352164 Choke tube - chrome (I think you already have this) $20

351250 Choke tube in manifold $11

351271 Manifold bolt & stud $7

Their website is very good and they have exploded drawings of all their parts. Just search on their part number.

Their description for the tube in the manifold says it is stainless, and I am sure it is.

The bolt/stud goes in the rear bolt of the center port. There is a bracket fastened to the choke tube that bolts to it. You will need it if you don't already have it.

-Dan-

[Patrick C.]

Re: 1964 FI Choke Issue

Pat,

I bought the choke stuff 10 years ago from Corvette Central. I just checked their website and they are still available under the same P/Ns that I bought them under. Looks like prices have gone up about 10%, which isn't bad for 10 years.

You haven't indicated if you have the tube assembly from the bottom of the manifold to the air filter adapter, so I have included it here.

351270 Air filter tube to air filter adapter $34.00

352164 Choke tube - chrome (I think you already have this) $20

351250 Choke tube in manifold $11

351271 Manifold bolt & stud $7

Their website is very good and they have exploded drawings of all their parts. Just search on their part number.

Their description for the tube in the manifold says it is stainless, and I am sure it is.

The bolt/stud goes in the rear bolt of the center port. There is a bracket fastened to the choke tube that bolts to it. You will need it if you don't already have it.

-Dan-

Thanks Dan, I will do my research tonight and order the parts. I have the tube from the manifold to the choke.

[Dan D.]

Re: 1964 FI Choke Issue

Pat, the biggest problem you may have is getting the old tube out of the manifold. Given that it is very old and rusty, it is most likely frozen to the manifold and pieces will just break up. You may end up doing some drilling, but keep in mind at least on the bottom it has to be a press fit in order to seal out exhaust gasses. Topside, the tube itself does not have to be a press fit, and probably is best if it isn't, as trying to press in a thin wall tube through several inches of iron can be difficult to do without damaging the tube. As long as the flare is a press, then you are sealed. I put some muffler sealer around the flare when I installed mine as the fit was not real tight. All is well so far.

It should not be that hard to remove the manifold. I have done it several times. 6 bolts + the 3 on the flange and any accessories bolted to the front - alternator for instance.

-Dan-