Thermoquad Dripping at idle.Help!

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Aus360

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Hey all you TQ gurus! I have a problem which has been driving me mad for weeks. My 850 TQ will not stop dripping from the L/H side booster at idle no matter what I have tried.

New needle and seats,swapped from side to side,no luck. Same with the floats. Set the fuel pressure regulator to 3psi,still drips. Idle is rough,and I
nearly die from the fumes! The primary wells are not leaking,just the L/H booster.

The carb runs awesome on the primary's and secondaries,great TQ throttle response,just wont idle. I have the carb off the car ATM,its in great condition
but the throttle shaft is a bit wobbly which worries me,so im waiting for a bushing kit I ordered. Any ideas??
 
Dripping from center of the booster?! This is normally a float not set right or the needle and sea on sealing flooding out that particular side.

Nitrophil floats? Double check that there still able to float. Submerge them and let sit. If they don't float after there under for a little while, there a slow leaker and sinking in the bowl.

It may take a minute or a day to find out.
 
Yes its dripping from the centre of the booster nozzle. Ill check the the floats again,i have tested them before and they looked ok.Ill check needle and seats again as well.

Ive set the floats at 29/32'' and tried the factory 1'' setting as well but still drips.They are the nitrophyl floats.Needle and seats are new,and the seats are tight. Seat gasket looks ok. Man im stumped,i don't want to put the 3310 back on,lovin the TQ REsponse and sound!
 
The nitro phial floats can go bad. If such is the case, PM me, I have a set you can have.

Also, this may sound stupid but are you sure every screw is tight?

Also, that bushing kit ... Where did you get it. I've never seen (or looked) for one. Where did you get it and is it custom to the carb.

I particularly like the TQ a lot. It may give up a few ponies to the Holley, but for a stock carb, these things rock. I find it hard to justify spending the money (again) on Holley a d not the base units for my street - street-strip ride.

If and when I start racing again at a comp level, where serious coin gets dropped for a serious Holley for a serious engine, well that is a different story.
 
Throw those floats in the ditch and get you a pair of brass floats.
 
Rumble; Everything is tight,im going to pull it apart again while its off the car and look at everything with a magnifying glass.I checked all the air bleed passages for a blockage too but all looks good.I got the bushing kit from Quadrajet parts.com. Its got enough bushings for three jobs,uses a piloted drill bit. They say it will fit any carb with a 3/8'' shaft size.

I love the TQ,the 360 really seems to like it. I like the 3310 as well, but it doesn't seem to have the sharp response of the TQ.Uses more fuel too.They are very hard too beat for a street carb when their right hence why I want to keep it. Thanks for the offer as well!

Rusty; I thought about this too,but ive swapped over floats and changed them and the problem is still there. What the hell,maybe I should just try some brass ones. Are they less prone to leakage?
 
Unlike nytril floats, the brass floats cannot become porous. Before I did that though, I would disassemble the carburetor and look very closely with a magnifying glass at the carburetor top and the plastic body in the area where the leak is. There may be a crack there.
 
Ha ha ha ha ha!!!!!!

I don't think I have any brass ones to give. I'd like a quartet!

Cracks in the bowl have been sealed up with JB Weld without issue here.
I don't know what any key else uses.
 
Even with the floats set correct and the needle and seat verified good, I have found that too high an idle setting can cause this drip. I am not talking idle RPM, but primary blade settings to far open, past the idle circuit hole. This allows increased flow past the nozzles, pulling fuel out. Try adjusting the blade, idle speed screw, to close the blade a little, then get your RPM to specs other ways, initial timing, PVC flow, etc. If you have a cam bigger than stock, these adjustments may be hard to zero in on.
 
Can nitrophyl floats be faulty from new? Because all the ones I have are new. I cant see four brand new floats being faulty. Just sayin'! Im thinking maybe because of the wobbly shaft, it could be drawing extra air into the primary that the idle circuit is not 'seeing' then drawing the fuel through the booster. It might be drawing a long bow with that one I know,but im willing to try anything now!

For the record ill give my engine specs: 360,10:1 comp;Eddy RPM heads and intake; Comp Cams XE268 cam 0.477/0.480 lift,224/230 @ 50thou duration;110LSA;Crane 1.5 rockers;1 5/8'' headers,dual 2.5'' exaust. I have an adaptor for the TQ on the RPM intake.MSD billet distributor,HE coil, Timing currently 14deg initial;36 total.
 
I doubt the new floats are bad. Nice combo.

Address the shaft issue first and report back.
 
RustyRatRod said:
Since they're new, I agree.
Click to expand...

Ok cool. Thanks for the input guys. hopefully ill get the bushings later in the week. Would like to post some pics too,Whats the best way? Im pretty new to this stuff!

MOPE69 I have noticed a little misalignment on that side,i think the bushing might fix it. I reckon you could be right,we'll see I guess!
 
FIXED IT!! The air horn gasket was the wrong one. It had the later type on it which didn't seal off the idle feed ports between the air horn and the fuel bowl. Especially on the L/H side. I did put the bushings in the primary shaft too,feels much better.

I cant belive I didn't notice it before ha!
 
Well how bout that? Good job.
 
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