Rebuilt Thermoquad issue -- It has to be primed before start each time

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Just lettin yall know.......JB Weld is not impervious to gasoline. I found a product a few years ago that is. It is called Seal All. Comes in a tube and it's like a clear glue, but once it sets up, it's SET UP and it is completely impervious to gasoline. It works very well. It's a little runny, so you need to be careful but as long as you are ready for it to come out, you'll be ok. O'Reilly carries it. This is what it looks like. It flat WORKS.

https://www.oreillyauto.com/detail/...970/chevrolet/c20-pickup-rwd?q=Seal+All&pos=0
 
So in the first test I did gasoline for 15 minuted in just the oil pans, In this test I did diesel for 24 hours in the oil pans and bowls. Not a sign of moisture coming through the oil pans or the bowls in either case unfortunately.
JB weld may not be a perfect&permanent fix like RustyRatRod said but it seems to be holding here although its only a couple of weeks old.

Any theories? The whole plastic part of the carb seems to be good after inspection and these tests..

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Maybe it is just the the acc pump well that is losing its prime. Or maybe you have a piece of debris in the acc pump well. There is a check ball in the bottom of that brass disc. if it is getting dirt in it or in the discharge orifice and you step on the throttle a lack of pump shot will cause it to stall. I would tap the acc pump back out and blow out the check ball with carb cleaner then air. And while you have it apart, run a small drill bit through the cast discharge hole that the hose connects to. Take it apart over top of a whit rag, so you can see if any debris falls out. Double check the acc pump well seal while you are in there. It is not on upside down is it?
 
Dana said:
Maybe it is just the the acc pump well that is losing its prime. Or maybe you have a piece of debris in the acc pump well. There is a check ball in the bottom of that brass disc. if it is getting dirt in it or in the discharge orifice and you step on the throttle a lack of pump shot will cause it to stall. I would tap the acc pump back out and blow out the check ball with carb cleaner then air. And while you have it apart, run a small drill bit through the cast discharge hole that the hose connects to. Take it apart over top of a whit rag, so you can see if any debris falls out. Double check the acc pump well seal while you are in there. It is not on upside down is it?
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There was a small bit of dirt died in or stuck on the the brass disc which a scraped away, it was in the corner part where it goes from flat to 90 degrees up, other than that it seemed clean .. forgot about the rag when I did though, so something could have been missed... The check ball was clean and functioned perfectly when i tested it again with my mouth, cleaned it out anyway. The discharge hole was clear but I cleaned it up with a drill.
Which part is the acc pump well seal? The brass disc or the rubber on the pump?

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I did a test:
I manually filled the pump well with fuel, then the pump circuit works and I could pump it and make fuel squirt out of the two nozzles in the primary.

Then I did the test again filling the pump well and the corresponding bowl and put the two parts of the carb together, I could once again pump it and make fuel come out of the nozzles in the primary. However after a few pumps it ran out of fuel.

Then I filled the bowl only and did not manually fill the accelerator pump well. This time nothing happened when I pumped it. No fuel came out of the nozzles in the primaries.

Then I removed the brass disc with a ball and replaced it with the original one that came with the carb. (I had changed this part with the new one that came in the kit). I then filled the bowl and put the two parts of the carb together, tried pumping it and it worked??? :realcrazy: WTF?

The rebuild kit is form HYGRADE and seems good, the Orings are actaully Xrings which apparently cheap rebuild kits dont provide. When inspecting the non functioning brass disc it looks perfect and is identical with the original, it also performs identically when you test the valve with your mouth. Still have to assemble and test it on the car but it seems that the original disc allows fuel to enter the accelerator pump bowl whereas the new one did not.?
 
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I usually prefer the brass also. But, if the other is what it wants! It sounds like the intake check isn't working quite right in the brass one. BTW are those the floats that came in that carb? What is the list # on the carb?
 
Dana said:
I usually prefer the brass also. But, if the other is what it wants! It sounds like the intake check isn't working quite right in the brass one. BTW are those the floats that came in that carb? What is the list # on the carb?
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Oh both are brass, they are literally identical to look at! These floats came on the carb, whether or not that have been changed I don't know, I assume they haven't. They are the brass floats that are rectangular without a cut out slice/section, from what I understand you measure float hight from the middle of them, from the seam. The carb is a TQ9140S. I think that made it an early 70's if I recall.
 
Yep,
BigBlockMopar
and
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purplehazenils

….Have it right. Those pesky little transfer housings are the culprit. 35 yrs ago, when the TQ was easy to find, the first thing I did was reseal the transfer housing. Or oil pan as they call it. Problem averted.
 
I did a test run with the car, shut off and started the engine a few times and the problem is solved. It was the brand new brass disc with a ball valve pictured in post 29 that was dysfunctional from the factory..
Thanks for all the input it was a big help in knowing what to look for!
 
The problem came back after about 3 days and maybe 20 starts. Its worse than ever and its not possible to put the car in gear with a cold engine without it dying. Will have to take it apart again and see whats up this time.
 
check choke adjustment and see if it is coming up on the fast idle cam. sounds like it needs more choke and more fast idle cam
 
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