Fast cam setting idle on a thermoquad

[Pratty]

Hi all, I've got a TQ that has two vacuum pulloffs, the one on the side of the (electric in my case) choke setting and another on the other side where all the fast idle cam and rod are. It's fully restored and after adjusting air door, choke kick and other settings, is going beautifully but for one thing. I'm no expert but I am a mechanic and have been trying to understand how to get these great old carbs running right. I know how to engage the choke for cold starts and that works fine. After going to the floor with the accelerator, slowly release so the fast idle screw rests atop the fast idle cam. All good. But my fast idle screw always ends up right at the end of the first step, as in, the highest speed setting, just near the drop to the second step. I can't get it to end up coming to rest on the second step, just before the step up to the highest first step. Consequently, or maybe its for a different reason, if I set the fast idle to say, 1300 RPM (auto trans), it starts fine but the slightest touch of the throttle drops it down and stalling on a cold morning is a problem. What am I missing here? Cheers and thanks in advance to anyone who has some thoughts on it.

 

[Geoff 2]

Comments. I am in Sydney & have worked on these carbs since the 70s. I remove ALL the choke mechanism, not needed in our mild climate. The triple booster primaries do not need a choke.

- The Ford TQs had some ridiculously small sec jets, some were 0.098", smaller than the primaries!!
- Get rid of the restrictive Ford fuel filter & replace with a Ryco or similar in line paper filter.
- The factory spec for the air valve spring is usually 1 1/4 turns. I watched a TQ on the dyno earlier this week that was set at 1 1/2 turns & it had a power dip. Set it to 2 1/4 turns, dip was gone.
- Enlarge the sec jets to 0.125" [ 1/8" ].
- Removing the elec choke housing will leave a vac port exposed; be sure to plug it.

 

[493 Mike]

The rod connecting the cam is the usual adjustment point. Bend it to raise the screw up higher on the cam. A service manual would show the exact area to bend. I have never seen a TQ on a Ford or with 2 pull-offs. Of course I've never been to Australia!
Mike