My '67 Idles really rough when I can get it to actually idle. Also when I stop at a traffic light or stop sign it always stalls. This econo has a 302 from a 1972 bronco that was custom fit. I've had this truck since 1991 and it's always ran good and purred like a kitten when idling.

Things I've done to rectify the problem are as dollows.

cleaned the carb with carb spray. replaced the points and condenser. installed new ignition wires. checked spark plugs (good condition). replaced air filter and fuel filter.
Since the plugs look good I think the ignition system is healthy but I cannot check the timing because the engine doesn't have the proper balancer . Fuel is pumping with plenty of pressure.
The next thing I suspect is possibly a vacuum leak.

Somebody suggested the new ethanol gas is the problem....
Any advice is much appreciated.

 

if it is a vacum leak you should be able to partialy cover the carb venturi when it is running and smooth it out some. also it will idle up when you do this.

i dont think it is ethanol, it usually doesnt affect carbs much. cant say the same about e.f.i. systems tho.

i personaly use wd 40 or carb cleaner to locate vac leaks by spraying it around the carb base and any vac fittings on the motor, but remember it will burn!

 

Jim,

I found that closing down the choke plate a little bit helps with the idle. Tomorrow I'll try that trick to locate a vacuum leak.

To check if the vacuum advance is leaking should I unplug the vac line to it and plug it?

Mike

 

Unplugging it would only make it not function. Find or borrow a hand vacuum pump to check the advance canister... or just try sucking on the hose really hard and see if it holds pressure or leaks..... Does sound like a vacuum leak could be your rough idle problem...

 

Well not much time for working on the Econo today. I had to put new pads and rotors on my wifes Honda grocery getter. Of course this required a couple trips to the parts store and then I had to test drive it to make sure it felt alright. Now I'm running outa daylight.
I couldn't perform the carb spray trick because there is way too much wind from the fan.
When shes sitting there idling I tap the gas, then when the engine slows from that tap she stalls. Every time. I decided to make sure the points were set right so when I took the cap off I was shocked to see the points are already worn out. I just put these in over the summer and I can't have even put 1000 miles on since then.
I'm thinking maybe I shoud check the gaps on the plugs while I'm at it.
Any other ideas why these points wore out so fast?

 

Too much voltage going to them, does your truck have a ballast resistor? The lead wire from the points to the coil is allegedly a resistor wire, they will break down with age....

 

The Econos do not have a ballast resistor. The voltage regulator can cause this same problem. Maybe replacing the voltage regulator and new points may solve the problem of stalling. I know bad voltage regs can also ober charge the battery and cause it to blow or burn out premajurely drying the battery cells.
I think the problem is the regulator. Replace it, they are not to expensive.