ThermoQuad Experts - need help

Posted By: 70mopes

ThermoQuad Experts - need help - 11/14/11 07:44 PM

I'm stumped. the choke pull off setup on my thermoquad appears to be in the right config but when it pulls off it holds my secondary air door shut (on top) How is this supposed to be set up? This can't be correct. Can anybody show me how this side of the carb should be set up?
Thanks

Attached picture 6919190-IMG_2161.jpg

Posted By: Rapid340

Re: ThermoQuad Experts - need help - 11/14/11 07:47 PM

Your setup is correct, it is there to slow the opening of the air door when vacuum drops under wide open throttle.

Posted By: mo71cuda

Re: ThermoQuad Experts - need help - 11/14/11 07:53 PM

Is the air door held closed at normal operating temp. or when the engine is still cold.

Posted By: 70mopes

Re: ThermoQuad Experts - need help - 11/14/11 08:12 PM

Normal operating temps... the pull off has a constant vacuum on it making it super tight at idle. Is that the way it is supposed to be? If vacuum dropoff under full throttle would cause the pull off to release, I guess I could see that as being a possibility. Seems weird. Perhaps extend the pulloff rod to allow for the choke pulloff to release quicker?

Posted By: DaytonaTurbo

Re: ThermoQuad Experts - need help - 11/14/11 08:58 PM

Re-read rapid340's post. He explains it. The purpose of the choke pull-off is so when you snap to WOT, the 2ndary air door opens slowly as the vacuum solenoid goes from the closed position to the open position. Yes it's just a couple seconds of difference but that's how it's designed.

Quote:

Is the air door held closed at normal operating temp. or when the engine is still cold.

Both. So long as there is vacuum, the 2ndary door is held closed.

Posted By: mo71cuda

Re: ThermoQuad Experts - need help - 11/14/11 09:03 PM

Your secondaries are opening at wot and working properly?

Posted By: dOOc

Re: ThermoQuad Experts - need help - 11/14/11 09:08 PM

MAYbe he needs that newer and improved TQ AV tool ? ...

Posted By: 69L78Nova

Re: ThermoQuad Experts - need help - 11/14/11 11:29 PM

Quote:

MAYbe he needs that newer and improved TQ AV tool ? ...

I know I do!

Posted By: Sunroofcuda

Re: ThermoQuad Experts - need help - 11/15/11 12:04 AM

Quote:

Your secondaries are opening at wot and working properly?

Here's the key question. ARE your secondaries opening after the engine is fully warmed-up? If not, then the wire sending power to the choke spring may not be allowing the butterfly to open all the way - it may not be sending juice. On a cold start, the primary butterfly will be closed all the way or else it will not start. After the engine is fully warmed up, the extra heat the power wire is sending to the manifold spring allows it to uncoil enough to open the butterfly all the way. My '73 Charger 340 had this problem & I could never get the secondaries to open.

If you are not sure if the secondaries are opening, wait for the engine to come up to full operating temp, then shut it down. Disconnect the choke arm on the butterfly & take some mechanics wire & wire the butterfly full open. Take it out for a ride. If you are having the same problem I had, it will feel like you bolted on about 80 HP.

Posted By: DaytonaTurbo

Re: ThermoQuad Experts - need help - 11/15/11 12:53 AM

Quote:

Here's the key question. ARE your secondaries opening after the engine is fully warmed-up? If not, then the wire sending power to the choke spring may not be allowing the butterfly to open all the way - it may not be sending juice. On a cold start, the primary butterfly will be closed all the way or else it will not start. After the engine is fully warmed up, the extra heat the power wire is sending to the manifold spring allows it to uncoil enough to open the butterfly all the way.

That's not quite right IMO. I ran the stock choke on my thermoquad for 8 years as a daily driver and never had the electric part hooked up. The choke does still fully open. The intake manifold gets heated up enough. After driving it like that for 7 years I put on headers and aftemarket heads with no heated crossover and the stock choke still worked fine. Also, the service manual for mine specifically said the primary butterfly door should NOT be fully closed when the choke is fully engaged. Should be open about a pencil width in front. I adjusted mine that way and it started easier and ran better when cold than it did with the door totally closed.

Posted By: dOOc

Re: ThermoQuad Experts - need help - 11/15/11 12:57 AM

Quote:

The intake manifold gets heated up enough.

....ESPECIALLY if it is an alum intake.

Posted By: dOOc

Re: ThermoQuad Experts - need help - 11/15/11 01:00 AM

Quote:

Quote:

MAYbe he needs that newer and improved TQ AV tool ? ...

I know I do!

LIKE this one ? ...

Attached picture 6919585-DocsTQtool.jpg

Posted By: DaytonaTurbo

Re: ThermoQuad Experts - need help - 11/15/11 01:00 AM

Quote:

Quote:

The intake manifold gets heated up enough.

....ESPECIALLY if it is an alum intake.

I tried it with a stock iron intake. With both the stock heads with the heated crossover and the aftermarket heads without. Took an extra 5 minutes of driving for it to warm up enough but it still got there.

Posted By: Sunroofcuda

Re: ThermoQuad Experts - need help - 11/15/11 01:53 AM

Mine never did, & I had a new choke mechanism & even bought a NOS solenoid for the intake. Never could get the secondaries to work unless I wired open the butterfly. I HATED that carb!

Posted By: 69L78Nova

Re: ThermoQuad Experts - need help - 11/15/11 03:21 AM

Quote:

Quote:

Quote:

MAYbe he needs that newer and improved TQ AV tool ? ...

I know I do!

LIKE this one ? ...

Exactly like that one

Posted By: DaytonaTurbo

Re: ThermoQuad Experts - need help - 11/15/11 03:32 AM

Quote:

Mine never did, & I had a new choke mechanism & even bought a NOS solenoid for the intake. Never could get the secondaries to work unless I wired open the butterfly. I HATED that carb!

And mine always worked so well! That was the best running automatic choke vehicle I've ever driven.

Posted By: 69L78Nova

Re: ThermoQuad Experts - need help - 11/15/11 03:41 AM

Quote:

Quote:

Mine never did, & I had a new choke mechanism & even bought a NOS solenoid for the intake. Never could get the secondaries to work unless I wired open the butterfly. I HATED that carb!

And mine always worked so well! That was the best running automatic choke vehicle I've ever driven.

For me, Thermoquads are the next best thing to fuel injection

Posted By: 70mopes

Re: ThermoQuad Experts - need help - 11/15/11 07:35 AM

Thanks for all the inputs. Was not familiar with the odd vacuum setup on Thermoquad secondaries.
Found out the following:
Was getting weak power out of the 360 on my Trailduster, turns out the secondaries were not opening under WOT - not consistently anyways. Found that when the choke was fully open, the linkage was not in the proper position to allow the secondaries to actuate. I corrected that problem with a couple of tweaks to the linkage. I also adjusted the air door pull off rod length. Mine was too short causing the air door to not open properly under WOT. Also set metering piston and bumped the timing back 5 more degrees and now power is up. Spring rate on secondary air door could proably use some tweaking. Where can I get one of those swanky tools?

Thanks again to all.

Posted By: Rug_Trucker

Re: ThermoQuad Experts - need help - 11/15/11 03:07 PM

Those tools are Doc's ELECTRIC BANANAS!! [/COLOR] I bought several. Gave some as gifts. Can't loose them in a tool box drawer!

Posted By: MRHWS

Re: ThermoQuad Experts - need help - 11/15/11 03:20 PM

My eyes..... My eyes.....

Posted By: Sunroofcuda

Re: ThermoQuad Experts - need help - 11/16/11 02:39 AM

Not all Thermoquads operate like this. I've had others where there was a small elbow piece of linkage on the RH side of the carb that I had to shorten by squeezing it tighter together - THEN the secondaries opened on that car. Don't get me wrong, I LOVE the Thermoquads, I just hate when the secondaries won't open. On my '73 Charger 340, I could find no problems with the linkage, it was all in that choke setup. The carb was rebuilt by a really good Thermoquad guy too.

Posted By: DaytonaTurbo

Re: ThermoQuad Experts - need help - 11/16/11 06:04 AM

Yes I've always had to spend some time tweaking the linkage to get the thermoquad to run well. Seems just to be the nature of the beast.

Posted By: Rapid340

Re: ThermoQuad Experts - need help - 11/16/11 01:54 PM

I have seen instances where the air cleaner base would interfere with the choke linkage (on the passenger side) and would inhibit secondary opening.

Posted By: Rug_Trucker

Re: ThermoQuad Experts - need help - 11/16/11 02:07 PM

I wired my secondary block off so it would open even with the choke on. I had converted it to a manual choke too.