Hello,

I would like to know what is exactly the high step of the fast idle cam.

So, when you put the fast idle cam on its high step, does it mean one of the notches is the high step or is it the area located on the cam after the notch ??

I know it's not really clear but I hope someone can help as I am not sure of my translation.

Thanks a lot.

I was trying to find a pic for you, but I couldn't... if in need, I can snap one of the carb laying on the floor in the garage.

if you're looking at your carb from the passenger side, and you see the black choke, right behind that (towards the drivers side), you have the primary throttle linkage. The fast idle cam, is a funny kidney shaped gizmo, that is on that primary throttle rod. .......long pause here...
ok, a picture is worth a thousand words, as I realized there was no way I could get away with saying "gizmo" and "doodad"

red arrow is fast idle cam

green arrow points to the "teeth" on the underside of the cam. Those are the steps. When the car is cold, the big "head" (red arrow) of the fast idle cam should be up. After the car warms up, the head should drop, counter clockwise.

the green arrow here shows the "thingy" (someone can jump in and name these parts better...) that touches the fast idle cam. This is directly connected to the primary throttle linkage. The tip of this is pointed top left in the picture ok? So when the tip of that is pushed counter clockwise, it rotates the primary throttle rod, such that it's like holding the gas open a bit (hence, fast idle). As the fast idle cam goes onto lower steps, the tip of this gizmo gets to go back clockwise, going back to regular idle..



Clear as mud?

Thanks for your help in fact I already knew that.

When you do the setting for the fast idle cam, you must open the throttle and then put the cam on its high step.

So I know when they mean high step, it should be (the fast idle cam) almost in a vertical position. I assume it's logical, isn't it ?? Am I wrong ??

Now what is unclear (at least for me) is the following : does the cam has to be put in a complete vertical position, so the part under it (with the fast idle screw) isn't in contact with the cam on one of the notches or does it have to be in contact with one of the notches of the cam when you turn the screw ??

That is my question Hope you can help

ah, well if you're setting it manually, it's useless. If you set the fast idle when the car is warm, it won't be the same as when it's cold. (so don't bother doing this after the car is warmed up)
When you get into the car, and it's cold, tap the throttle, then go look at the carb. The primary throttle blades should have snapped shut, and the fast idle tang should be all the way up. If not, you must reset the choke. If so, then start the car and adjust it.

Now to answer your question without beating around the bush anymore, you should be able to twist the throttle cable (ie, rev the car, but when the car is off), and pull the fast idle cam as far clockwise as you can, then let off the throttle, and the fast idle cam should stay. That's the highest step, which I believe is the rounded part of the "teeth", above all the teeth. Almost vertical, but slightly off I think. This should be the rpm the car goes to on a cold start. So the "thingy" should be on the highest part of the fast idle cam, when you first cold start the car, and that's when you turn the phillips screw to adjust your fast idle RPM.

hope that answers all questions.

if you're setting your choke/cold starting conditions from scratch, check the post I made recently about setting your choke. I made a pretty extensive post about how to set it all up. (unless you just need to adjust your fast idle speed, then you're set).

I know about all the setup process but I wasn't sure about the step on the cam.

From what I read, my setup wasn't exactly what it should have been due to that misunderstanding of mine, so I think you've completely answered my question

Thanks a lot for you help !!!

Finally, I think I've found a good setup for the cold start.

It starts, without pumping on the gas, at first try. It doesn't smoke or smells gas and it idles nicely around 1000 rpm when cold.

But I have another question. When the choke flap is completely open, idle rises a bit (around 1200 rpm) and when I push on the accelerator to stop the cold idle cycle, the engine hesitates and has some difficulties to rev. But I didn't notice black smoke or things like that at the exhaust.
So I push harder and it goes to regular warm idle, around 700-800 rpm in Park.

After it is in the 700-800 rpm range, if I accelerate, there isn't any problem. It revs nicely, without hesitating.

So what causes the engine to hesitate when I want to stop the cold idle cycle ?? A vaccum leak somewhere ??

Thanks !!

you should have to tap the gas at first when you cold start it, but not pump it.... (you still tap the gas right?)


I don't worry about any driveability problems when on choke, as it's running pretty rich then anyway, and I just baby it until it's warmed up right.

Yes, sure, just one time, in the goal to get the choke flap to close.

I've done the test with the air filter box in place and strangely it runs fine.
Although the idle is slightly lower, it starts at first try after I tap the accelerator one time, and when it's getting warm, it revs without hesitating.

So I will try to test drive it tomorrow