checking my TQ performance

[billschroeder5842]

How can I test to see if my TQ is opening the 4 BBL?

My 75 roadrunner, with a 400 4bbl and a thermoquad runs very smooth and dependable. However it feels like it is lacking in the "oomph" department. Yes, it is a 75 and full of smog stuff, but it should have a bit more?

I'm wondering if the secondary's on the 4 barrel are opening? I messes with the linkage enough to know that I'll mess something up.

Carburetors mystify me so how can I see if the 4bbl is working properly?

Thanks!

[Cooter]

All TQ carbs had mechanical throttle bores, but relied on an air flap on top to help control stumble ( vacuum sec.)

If you hear that distinct moan, it's opening. You could try the WOT snap test while in park to just see if the flap in top is opening.
basically, snap throttle wide open and flap should move. 

These carbs do have a provision if the choke is 'set' it will NOT LET MECHANICAL LINKAGE WORK REAR barrels.
Make sure all linkages are sprayed with WD40 and aren't sticking.

[billschroeder5842]

Thanks-The snap test shows it is not working nor do I get that "WWOOOAAAA" sound when I punch it.

I checked the shop manual diagram and the linkage SEEMS to be correct. I can manually move the linkage around at the rear/side of the carb and get the 4bbl to open but cant seem to make the connection between WOT and getting it to open.

It seems I can bend some things to get it closer to working but am concerned about messing something up---it really does run well albeit as a 2bbl!!

[John_Kunkel]

On the drivers side of the carb there is a device called the "secondary lockout", its purpose is to prevent secondary opening unless the choke is full open....be sure the choke is full open and the secondary lockout is properly adjusted.

[billschroeder5842]

Yep, you got it. I adjusted the tang "up" according to some of the photos I saw. The 4bbl instantly opened and the "Wwhhhaaa begun"

Now I have a smog bundled 75 that runs very well with the illusion of 4bl power.

Thanks!