Just as titled. I have an 85 gs with a rebuilt carb as of 3 weeks ago, mechanical secondaries, and emissions removed. Car ran VERY well for the last couple of weeks then all of a sudden it ran like it was down a coil or too rich.

Come to find out that with the car warming up (and running), the primaries and secondaries and both dumping a ton of fuel into the barrels. Choke is normal as far as pull and rpm, along with throttle cable as well.

What would cause a carb, with the engine on, to dump gas into the barrels? What actuates that when the engine is on?

 

float needle maybe stuck....tap the carb with a rubber mallet..good luck

 

In order of most to least likely:

Stuck float needle(s)
Needle seat(s) missing sealing washers or not tightened properly
Worn float needle(s)
Float(s) binding in bowl(s)
Saturated float(s) not floating high enough
Misadjusted float(s)
Fuel pump overpressure (only if both front and rear involved)

 

It baffles me that the new float needles could be stuck but it makes sense. It seems to be both sides tho...

 

They tend to be prone to it while new; once they break in, the problem goes away.

 

It worked flawlessly for about 2 weeks tho....

anywho, took the carb apart to find nothing visibly wrong with the floats or needles. Took those assemblies apart, and everything still looked good just like when I put them together about a month ago. Going to clean up the plugs and fire it up (hopefully) tomorrow to see if gas is still dumping into the carb.


There is a hose next to and slightly below the fuel return line. This hose is vacuum.....and comes off the same mount/cast as do the fuel lines. Anyway, when I took this hose off to remove the carb, some gasoline came out which surprised the hell outta me. Why/how was there fuel in this line? May be from all of the fuel being spat into the carb that it got backed up?