kickdown linkages

Does the C4 transmission have a kickdown linkage when used with a 302 with a Holley 4 barrel carb used?

What about a manifold vacuum line?

Mine has neither & basically works fine. I just noticed it when replacing some missing vacuum lines.

All C4 trans have a kickdown linkage of some sort depending on year, and also have a vacuum line to modulator valve on trans. There should be a metal tube sticking up at the rear of engine going to trans where a vac. hose should be.

Since this is a Cougar forum I will assume that you have a '68 since that is the only year a Cougar came with a C4. There is no kickdown linkage connected to the carburetor in any 1967 or 68 Cougar with any transmission. The very short kickdown cable connects to the throttle linkage under the car if the car has an automatic transmission.

What did a ‘67 small block come with?

Same except there was no 302 in '67 so he has to have a '68.

The 67 would have come with a C4

The 302 came out in '68 so it’s not a '67.

Yes, it’s a 1968 that originally had a 302 2v. The engine has been rebuilt with GT40 heads, 4v Holley carb (which I hate – adjustment is nightmare). The main agenda is getting it inspected so I can ditch the historic tags.

We can walk you through adjusting the Holley. It is really not that hard. What carb do you have? You can get the list number from the front of the air horn.

The list number is list-9834-0847.

I’m not sure what the cfm is, doesn’t say. Overall it acts like it’s way to big for the engine.

If I was on the Autobahn, it would be perfect. Stop and go traffic, not so much.

My last cougar (1970) also had a 302 with a 600 cfm Edelbrock. That one had no problems with low end power.

The total fuel capacity for this one is probably 3 or 4 times more then for the Edelbrock.

Compared to my last one, the Venturis and outlets to them are HUGE.

The engine floods if I idle it to low.

It appears to have 2 fuel bowls, a vacuum secondaries & one set of accelerator pump jets on the primary side.

Each of these bowls has its own bowl and float adjustment hex nut and screw that appear to be identical.

The fuel bowls have a side port that is probably for establishing fuel level, but it isn’t transparent.

Hopefully clear after market ones are available.

There is also an automatic choke with no electrical connections.

There are 3 adjustment screws in an upside down configuration with one on the bottom and two on top.

Heat operated?

The choke has a red cam with multiple steps on it, similar to the accelerator pump.

The accelerator pump has a yellow cam & I put the screw in the first quickest opening position.

This yielded some improvement.

There is no fuel pressure regulator and no pressure gauge. I have already ordered these parts.

The fuel pump appears to be stock mechanical but might or might not be a high flow model.

According to the dealer, the guy who built the engine tested it on a Dyno, chasing 300 flywheel horsepower, not on the street. He was said to barely get the number between well after 6000 rpms.

Weirdly enough, the intake looks like a stock duel plane crossover one painted like a stock engine.

I had the original exhaust manifolds that came with the car reinstalled by the dealer & told them to keep the headers.

Converting to a full manual choke would certainly give me more control.

Converting to that new 500 cfm Edelbrock AVS-2, which has something essentially like a mechanical fuel injector inside it seems to be the most idiot proof solution & I plan on using a manual choke.

I’m aiming for simplicity & reliability.

Of course, if I can somehow get the Holley to behave itself, I’ll save $300.

With either carb, the fuel pressure regulator isn’t strictly speaking necessary but using one really helps to cut down on leakage and flooding.

Looks like a 600 CFM Holley 4160. Just about perfect for your car. Should have an electric choke. I have never heard of a non electric automatic choke. Can you post a picture?

Here is one on Ebay:

Does that look like yours?

Ok, here it is (if I can post the pics)

The hose with the yellow stripe and the metallic one with the heat shielding go to the choke, nary one wire in sight.

No way that’s going to work, the clean air intake hole on the carburetor is plugged. It is a heat stove, not electric choke. Those were available in the 1960’s - 1970’s. Likely the lower pipe on your exhaust manifold got lost or broken off at some point in the last 50 years. There is (or was) a piece of steel wool in the bottom of the exhaust manifold that acted as a filter. They get plugged with rust and dirt, especially if the filtered air pipe is gone like yours.

Those are fabulous carburetors. I ran one like that on various small block Cougars for decades.

Where exactly is the plug located & will removing it cause a vacuum leak?

The choke itself actually works. I completely unwound it when everything was ice cold. Then I tightened it up until the choke closed. Then I gave it one full turn extra.

If that hose comes out of the manifold, it doesn’t work at all. That was part of the problem I had to push it in another quarter of an inch.

It opens up usually 6 or 7 minutes later. If that was the only problem, I’d be totally happy. The part throttle response and hesitation is the main issue. Idle and full throttle are great, all or nothing.

I actually have to slightly pump the gas pedal like you pump the brakes on ice in order to keep it from bogging down or laying down rubber.

The other ominous thing is that tightening the fast idle screw actually makes it worse!!

Raising the idle with the mixture screws presents no issues.

I have no doubt that in stock form, these were great to have. Like the other stuff on this engine, it’s probably highly modified on the inside and stock looking on the outside.

If I was a Holley guru, I’d get an identical replacement, but I’m not.

With the choke adjusted the way you describe, it will never be able to open. Generally, the best method is to adjust it so that the choke is barely closed when the engine is full cold, and ensure that it opens completely when the engine is warm. Without the proper parts to get heat to the choke spring, it’s not likely to open up even if adjusted “properly”.

Driving with full choke obviously is going to make your engine mighty rich once it’s at operating temp.

You should not mess with idle speed using the idle bleed screws either; that’s going to really mess with your idle mix. Generally, you put 'em at 1.5 turns out, set your idle speed screw, and then fine tune just a tiny bit with the idle bleeds to get best vacuum/smoothest idle, assuming your ignition’s really dialed in. Tightening the idle speed screw (making it stick out further, holding the blades open wider) speeds up idle, but past a certain point, it will make your idle circuit useless because you are in the intermediate circuit, uncovering the transfer slots. At that point, whatever you do to the idle bleeds is completely useless.

Make SURE that your ignition timing and distributor curve are set correctly before messing with your carb settings, or you will have no luck at all tuning your car. Additionally, all the fine tuning should be done when the car is already fully warmed up.

Holleys aren’t bad carbs; they deliver great top end power. But I’ve never been happy with them on a street car either, when compared with an Autolite.

The timing is just fine.

When I wound the choke back up, it closed and I did one additional full turn. Now it’s fine. It seems to work like a chimney & opens as the manifold warms up

There’s something else going on with it that I don’t understand. Trying another carb is the latest fastest way to fix it.

The fast idle shouldn’t make things worse. There are no vacuum leaks at the carb. I already went around it with an unlit propane torch and nothing caused the engine speed to increase.

I suspect that something inside of it is damaged or clogged up or seriously adjusted for top speed and nothing else.

If putting another carb on doesn’t fix it, I have to know that too. Once I get the Edelbrock on it, I’ll be giving it away in the free stuff section as long as I get paid shipping.

Chances are pretty good that the Edelbrock won’t run right the way it comes out of the box. Carbs have to adjusted to the engine that you put them on. It is possible that it will run okay but even if it does it won’t be optimized the way it should be.

Since the Holley is sitting on it right now lets go through the basics for setting it up right. Working with gasoline requires care. Have few rags handy to soak up spills, no smoking, no sparks, easy does it.

First off, back that choke off by the extra turn. You turn it to get the choke to just close when the engine is cold, no further. You will probably see a small alignment mark that will end up right on top and just about match the mark cast into the carb. The tube coming up from the exhaust manifold is coming from the choke stove and it is called the heat riser tube. Leave that hooked up.

There are two idle air screws on the carb. One on each side about half way up. They are small straight blade screws. Carefully rotate them in, counting the number of turns until they are gently seated. This number will help us later. Then back out each screw 1 1/2 turns.

On the side of the carb there are two large brass flat bladed screws, one on the side of the front bowl and one on the back bowl. These are sight plugs. They let you see how much fuel is in the bowl. Take then out with the engine not running. If gas pours out that is a sign the float bowl level was much too high. The fuel should just come up to the bottom of the opening, dribbling out just a little bit. Now start the engine and check the fuel level. Be ready to shut it down if gas is pouring out. The level is adjusted by raising the needle ad seat assembly. The adjustment is on the top of each bowl. You will see a large flat head screw with a thin 5/8" nut under it. Loosen the screw just enough to let you turn the 5/8" nut. Not much at all. To raise the fuel level you turn the nut counter clockwise. To lower the fuel level you turn it clockwise. These are small adjustments, one turn is a lot. I find that lowering the level below the window and then slowly raising it is the most accurate way to do this. To get the level below the window the engine has to run for a bit to consume the fuel in the bowl, just adjusting the level screw won’t make the gas leave the carb, it has to go into the engine. Be patient. When you have it so the gas just barely dribbles out, with the engine running, put the sight plugs back in.

Once you have the level set then you need to adjust the idle speed. This is done by using the idle speed screw on the linkage side of the carb. You should let the engine run long enough to be fully warmed up, and see that the choke butterfly is fully ope in it’s own. You want to get the idle to something around 700 RPM maybe a little higher. The next step is to adjust the idle air screws, the two that you backed out by 1 1/2 turns earlier.
When you turn the screws in the engine should start to stumble a bit, dropping RPM. As you turn it back out, the idle should improve. It takes a little time for the engine to respond to the changes so take your time. You are now listening very carefully to the engine. You want to back the screw out until no further improvement occurs. You should be in the ball park of the original 1 1/2 turns adjustment, typically less than 1/2 turn either way. If the engine doesn’t respond to the idel air screws at all, it means a more complicated adjustment is needed.

Let us know what you find.

This 9834 carb is a 600 cfm Holley with the Ford kickdown linkage. Properly adjusted it should run just fine on your car. An Edelbrock 1406 which is 600 cfm would also be a good choice. The best choice for a stock 302 would be the Edelbrock 1403 500 cfm carb.

Sounds to me like you have misadjusted floats or debris on the float bowl needle valves. If the choke does not have a pipe from the passenger exhaust manifold to the choke the choke will not release. You can spin the choke housing to take the choke out of the equation if you wish. Get it to work correct then spend some time on the choke. We can talk you through it, but you may need a professional assist you. The complete tuning of your engine requires timing adjustments and carb adjustments. And it assumes an engine in good condition.

We can help. It is not that hard.


I did not see the other posts. first do hat Bill says with the engine off and pull the “site window” plugs out to see if fuel pours out. If it does you have dirt issues or misadjusted floats. I would pin the choke to hold the butterfly open and lock it out. Take the choke out of the picture. You mention “fast idle screw” There is one on the passenger side that you can only access on the car if someone holds the throttle wide open. You need to make sure that screw is backed off so it does not touch the “red” fast idle cam you mentioned earlier. You want to take the choke completely out of the picture and the fast idle. Now on the driver side is the “curb idle” screw that sets your idle speed when hot. Not sure if you are referring to that as the fast idle screw. As Bill says 1.5 turns should be adequate to start with. You need to ensure you can get the idle speed down to around 650 to 750 rpm. As smilodon says if you do not get the idle down the throttle blades are to far open and your idle mixture screws are negated and non-operational.

Keep us posted. You should be able to sort it out.