Dodge Van 1979, 318 V8 2 bbl, AT Original 54,000 miles.

OK, 3 slow pumps on the pedal and it starts right up cold. Runs decent. Occasionally has a slight stumble at throttle tip in from low speed...but it had that since 1979- gd emissions tuning.

You can run this van slow or hard for 5 to 6 miles and it accelerates well, including foot on the floor. After 5 to 6 miles of 50 mph traveling it will start to stumble and eventually stall. It wont restart...spins over freely..not a hint of starting...I thought perhaps the spark was gone...it isn't. So you wait 5 to 10 minutes and then it starts again.

Today, driving with engine cover and air cleaner off, I tried to make it do it again. I drove around the plat 10 times at 30 mph,- about 15 miles- with occasional burst of acceleration, it ran great, even when i came to complete stops. I wanted to stay in the plat in case I had to walk home. Would not do it.

So, I was forced to take it out on the secondary highway, repeated the route that made it fail last time, ran it up to 50 mph a couple of times, came to an intersection and a stop sign, sure enough it started to run bad, couldn't save it by shifing to neutral and pumping the gas pedal gently and it died. This time I noticed a slight wetness near the base of the carb. So I pulled the spark plug wire and yes it does have spark. so then I waited as usual until the van was in a better mood and it started. On the way back it did it again. Waited, started.

Got home, shut off and watched, big plume of white smoke out carb (seen it do this the other times too) I assume this is gas vaporizing and I see again the wetness coming out base of carb.

So, I am thinking... Sinking Float?

These items in last 1k, however I only put a cpl 100 miles on it a year:
spark plugs
wires
cap, rotor
fuel pump
fuel filter
rubber fuel line
starter relay
starter
air filter

So it has gas, spark and air.

Vacuum gauge reads 19 mm at low idle speed, 21 mm at 1st step fast idle, reving engine and holding revs, vacuum falls but then climbs back to 21 mm

sprayed base of carb with water while runing to see if there was a leak...no change

Shook carb while running...no change

Choked air horn with hands and it started to stall indicating (no vacuum leak?)


So, what the heck is it?

By the way, I called Autozone and read them the tag numbers on the carb and they said they meant nothing to them and did I have a Holley or a Carter. It has lots of numbers but these three are separate and stamped much larger "333". anyone know which carb that is?

 

Hmm, sounds like the engine is flooding out. Can you tell where this wetness is leaking from?

 

the first time...at the end of the highwary run...I saw a drip on the throttle shaft linkage and some wetness around the base.


Then when I made it back home and shut it off I got a bigger leak that seems to come from the base of the carb, at gasket level, and it seems to come from all around the circumference of the carb at once.

Which leads me to think that...I don't have a schematic of the carb...it could be overflowing out the float bowl?

OR Could the metering needles be hanging up? that would account for poor running but I don't know if those needles stick, will they allow fuel to drain into the carb?

 

Yes to all of these questions. It sounds like you could have some dirt in the carb that is causing your problems. It might be time to strip it down, clean it, and replace all the gaskets.