Fuel System: dies at idle....Problem Solved!

[Lou Van Anne]

Started my V8 Champ today....she started fine when I noticed a "hiss"....as long as I kept my foot on the gas she ran fine....let off the gas and she dies.....any ideas?

[Bo Markham]

Look down the throat of the carburetor, give the accelerator pump a couple pumps and see if you have fuel coming out of both holes in the pump nozzle. You should see something coming out during idle, certainly during acceleration. If not, then you might have some debris plugging the nozzle up. Otherwise, the low speed/idle circuit is probably plugged up some where and you might have to take the carburetor apart and clean it real good. Either that, or you have a vaccum leak?

[DEEPNHOCK]

Sounds like a vacuum leak.....

[bezhawk]

Sacrificing the wrong snake to the wrong idol. Perhaps it's the idle you're concerned with? Like Jeff said look for a loose hose or other source of vacuum leak. Sometimes the PCV valve can stick. Also the brake booster can go bad, or it's hose leak.

[Dan Timberlake]

OP said "she started fine when I noticed a "hiss" "

DEEPNHOCK replied "Sounds like a vacuum leak....."


indeed it does

[Lou Van Anne]

(I never passed the spelling class in H.S.....)

Sacrificing the wrong snake to the wrong idol. Perhaps it's the idle you're concerned with? Like Jeff said look for a loose hose or other source of vacuum leak. Sometimes the PCV vale can stick. Also the brake booster can go bad, or it's hose leak.

[Lou Van Anne]

My suspicion also....going to check her out Monday...first place to look?

OP said "she started fine when I noticed a "hiss" "

DEEPNHOCK replied "Sounds like a vacuum leak....."


indeed it does

[RadioRoy]

Does the truck have a PCV valve? Does the truck have an automatic transmission so the transmission would have a vacuum modulator?

[Lou Van Anne]

3 speed with O.D.

Does the truck have a PCV valve? Does the truck have an automatic transmission so the transmission would have a vacuum modulator?

[StudeRich]

OK a Standard Trans. 62 Champ, it could only be a Distributor Vacuum Advance Hose, a PCV Hose or a Hydrovac Booster Hose if equipped, UNLESS it's the wrong or blown Carb. Gasket or loose screws on Carb.
The Bottom portion of a 2 Brl. has 4 hidden screws in the base upside down!

[Lou Van Anne]

Checked her out tonight.....two hoses run off the back of the carburetor: a small one about 1/4" and a larger one about 1/2"....the larger one had come loose from the base....going to try her in the morning....what are these hoses called?

[rbisacca]

Checked carb on my '62 Champ with AFB 4bbl. Large hose on carb rear is PCV. Small hose attached to front goes to dist. vacuum advance.

[TWChamp]

Just a guess without looking, but the larger one likely goes to power brakes or PCV valve. The smaller one might go to the vacuum advance.

[BrianC]

The large hose is vacuum to the base of the carb, the small one is vacuum advance to the distributor. Hold the idle with the fast idle screw, then tune the jets, you should be able to turn down the idle after that. If it bogs out then, check for vacuum leak at the base of the carb or the hoses, check that the choke is functioning properly. You may have to tweek the timing in combination with the adjustments.
if you can’t get a good idle after this, you may have to look at the float adjustment, make sure the needle valve is clean and seating properly. So many small things can cause the rough or no idle.

[Lou Van Anne]

Problem Solved!....reattached the large hose....the "hiss" is gone.....she's running great again! (Wish all my Studebaker issues could be this simple).