i put a thermoquad on my 78 440 and it seems very mushy. it does not have a crisp response. the engine is stock with a ch4b intake and headers. it pulls a rock solid 17in of vac and total timing is 34 degrees. where should i look for the problem. or is this common with TQ's.

thanks
Shane

How did you get a TQ to "fit" on a CH4B ?

the dreaded adapter plate.

Shane

You may be describing any smog 440 but keep in mind the thermoquad uses small primaries and LARGE secondaries. Try to verify that the secondaries are indeed opening. If the choke is not all the way off or if there is interference with the aircleaner base they will not open.

If that checks out, make sure the choke pull-off is allowing the air door to open. (the air door is directly above the secondary throttle plates).

Throttle response on the primaries should be quite good, I know mine always was. Stock camshaft? How much initial timing do you have?

8 deg initial timing, it had a 3310 holley on it that was flooding it with gas. it runs alot better with the TQ. it has the stock cam. also if you slowly give it gas it has a slight hesitation/bog.

shane

Check the secondary air valve adjustment,too loose it will fall on it's face,to tight it will take forever to get there.

also this carb was set-up/used on this engine while it was in a motorhome in Denver Co. would altitude compensation be an issue?
carb info.

Model Application
9150 78 440 Truck HD AT CA (4095441)

Pri. Sec. Rod
4099 5125 2110

bore 1 1/2


shane

You may want to cover the two #2 pencil lead holes at the inside of the choke tower wall. Use a small piece of tape over each hole, then go test-drive the car. If the results are positive, then put a dab of epoxy over each hole.

This will 'richen' the cruse and wot circuits, David.

Pic for refrence:

Thanks DemonSizzler i'll give it a try.

Shane

The smogger 440's are very sensitive to ignition timing, at least mine was. Try bumping up your initial to 12-14. Is your vacuum advance hooked up?