Another TQ question

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Bill Crowell

Bill Crowell

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I have a TQ on which I recently replaced the fuel bowl with an NOS one. I don't know what main metering jets it came with. I am using the same metering rods as I was using before, so this may well be a mix-n-match situation as far as main metering jets and rods are concerned.

The engine runs OK at idle, but starves for fuel on the primary high-speed circuit. I have verified that the step-up piston rack is engaged with and lifting both of the metering rods. Do you think I should lengthen the step-up piston rod adjustment because the (likely) mix-n-match jets and rods aren't letting enough fuel through, or look for some other problem instead?

Is there anything else that you think I should check? Thanks again. I really do appreciate your help.
 
There is a mechanic down the road who knows quite a bit about Thermoquads, and I think he will give me some free advice because he tried to glue my bowl wells back on with JB Weld Plastic and it failed. He charged me quite a bit, but I didn't ask for a refund because he is a nice guy; he is a smog tech who knows how to adjust the TQ to pass California smog; it is worth more to me if he feels a little bit guilty about it and will therefore give me lots of free advice to correct the problem; he has been known to put the vehicle on the dyno and adjust the step-up piston rod length for maximum power; and now that I at least know how to assemble a TQ it will be more convenient for me to ask him for advice and then do the repair at home.

So I'm gonna ride over there on my bicycle, hang around his shop and make a general pest of myself until I get a chance to talk to him, and see if he thinks I should lengthen the step-up piston lift rod, and if so, by how many turns to start with. I think he has the next couple of days off, so I might not be able to go over there for a few days.

I'll let you know what happens!
 
What carb base are you using? Maybe I can find rod and jet numbers to get you in the ball park. Do you know what is in there now?
 
A mix and Match combo? You have to do that on any carb except in a resto.

Adjusting the tree upwards brings in the enrichment earlier. If it is not enough when it is up, earlier will not make a difference.
Does the replacement fuel bowl have the same size venturi’s as the old one? What are the carb numbers?
 
Thanks for the reply, 66fs! The fuel bowl is a TQB-7. Yes, it would be a big help to me if you could tell me which jets it comes with.

I'm clueless on the rods, though. How can I figure out which rods I've got?
 
Thanks again for your help, rumblefish360. That's good info to have regarding the TQ's theory of operation, and maybe, as you say, lifting the tree wouldn't really help.

So I wonder if I am going to have to change jets? The rods must be too big if I am starving for fuel.
 
What is the carter number on the rear base? There are numbers stamped into the jets and rods also. Sometimes they need a magnifying glass and some brass cleaner/polish.
 
Do you know "WHERE YOU ARE" with the metering rod tree adjustment? If not, this will baseline you. Press the metering rod tree all the way down and gently bottom it. Hold it there. Adjust the adjustment screw until the tree is all the way DOWN while holding it lightly bottomed. Now, turn the adjustment screw until the tree JUST begins to rise. This is your baseline adjustment. From here you can adjust either rich (up) or lean (down) to make changes.
 
Wow, RRR comes through again! I didn't see that adjustment in the FSM at all, Rusty.

I'll make that adjustment. Thanks a lot.

Even if that doesn't work, it sure would be nice if, worst-case, I only had to change out the rods because I could do that with the carb on the vehicle and without removing the cover.
 
Bill Crowell said:
Wow, RRR comes through again! I didn't see that adjustment in the FSM at all, Rusty.

I'll make that adjustment. Thanks a lot.

Even if that doesn't work, it sure would be nice if, worst-case, I only had to change out the rods because I could do that with the carb on the vehicle and without removing the cover.
Click to expand...

That's because it's not there. It's one of those "adjustments" that was set at the factory and we were considered too stupid to mess with it. LOL
 
Bill Crowell said:
Thanks for the reply, 66fs! The fuel bowl is a TQB-7. Yes, it would be a big help to me if you could tell me which jets it comes with.

I'm clueless on the rods, though. How can I figure out which rods I've got?
Click to expand...

We’re running around in circles here Bill. Your not paying attention or you just don’t know. Which is it?

Do you now have rods and jets in the carb?


Bill Crowell said:
Thanks again for your help, rumblefish360. That's good info to have regarding the TQ's theory of operation, and maybe, as you say, lifting the tree wouldn't really help.

So I wonder if I am going to have to change jets? The rods must be too big if I am starving for fuel.
Click to expand...

I’m going to repeat myself here OK. Ready?

If the carb is not being used on a stock/resto engine, your more than likely need to change jets and or rods.

Bill Crowell said:
The throttle plate is a 6461S.
Click to expand...

That number is nearly as useless as ..... insert a crazy saying here......
On the carb base plate there are numbers.
What are they?
 
6461 S 1974 440TQ low performance California early, C body Plymouth, Dodge, Chrysler, Imperial. I will look up the jets and rods later as well as a 73 400 HP for comparison.
 
Last edited:
1.50 primary bores. primary jets 120-4098, secondary jets 12-5137, rods 75-2005 (.065 x .055 x .040)
 
Last edited:
66fs said:
6461 S 1974 440TQ low performance California early C body Plymouth, Dodge, Chrysler, Imperial. I will look up the jets and rods later as well as a 73 400 HP for comparison.
Click to expand...

66fs said:
primary jet 120-4098, secondary jet 12-5137, rod 75-2005 . 65 x .055 x .040
Click to expand...

And finally, the information shows up.
66fs, are you sure this is what Bill has?
 
You really need a wide band to tune a carb nowdays. Gas is much different than it was when these carbs were tuned making yesterdays tune not accurate today.
 
rumblefish360 said:
And finally, the information shows up.
66fs, are you sure this is what Bill has?
Click to expand...

No, he should verify exactly what he has. I have the 74 Chrysler Parts Manual and Carter strip kit info. This is what that carb should have had from the factory. Sounds like a good base line. The 1974 440 HP carb only changed rods to 75-1966 (.067 x .052 x .045). As we should know, the factory TQ usually needs a choke to start and run right till they warm up. They can work as well as fuel injection if set up correctly. Mine did on a HP 273 daily driver in South Dakota.
 
Bill Crowell said:
Wow, such misdirected anger!

rumblefish360, is something bothering you?
Click to expand...

Whoa. LMAO! You assume so much. Anger? LOL!

What does bother me is this answer.
Bill Crowell said:
I believe I have already answered all of your questions, rumblefish360.
Click to expand...
It’s extremely rude and untrue.
But that’s OK, you have fun with that ****. And your carb crap. It’s fine. I’m not gonna help. I’ll just watch......

This one is a peach too.

Bill Crowell said:
regarding the TQ's theory of operation, and maybe, as you say, lifting the tree wouldn't really help.

So I wonder if I am going to have to change jets? The rods must be too big if I am starving for fuel.
Click to expand...

If you like, just this once, I’m willing to break out the crayons and draw pictures for you on how the carb works. That is, if you can tolerate me regurgitating factory information and what was already printed out in books again.

That is, since you doubt. It’s really NO problem.
 
66fs said:
No, he should verify exactly what he has. I have the 74 Chrysler Parts Manual and Carter strip kit info. This is what that carb should have had from the factory. Sounds like a good base line. The 1974 440 HP carb only changed rods to 75-1966 (.067 x .052 x .045). As we should know, the factory TQ usually needs a choke to start and run right till they warm up. They can work as well as fuel injection if set up correctly. Mine did on a HP 273 daily driver in South Dakota.
Click to expand...

Oh thanks! For a second there, I thought it might have been actually possible that this guy knew or took some time to actually work on his garbage to know exactly what is in there and tell us so we could actually HELP HIM get somewhere with this project.

He was asked ..... not I....

Why is it such a popular thing not to answer questions about your particular problem and leave the ones trying to answer the question hanging and guessing?

It’s not like we asked what color the car was.

You looked up the carb numbers (you shouldn’t have to but if he doesn’t know where to get the numbers, no big deal if he said so.... right?)
Now we assume?
 
rumblefish360, you really need to figure out why you're so angry. Giving angry responses to questions doesn't persuade anyone. That is the opposite of persuasion. You obviously have something going on in your personal life that is making you angry, and you should figure out what it is rather than taking it out in your fellow FABO members.
 
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