Carberator issues

I think your explanation above is the clue to the solution. The Fox I6 has all kinds of vacuum lines, valves and sensors. With AC, they have a vacuum tank, that serves as a buffer for all the vacuum needs for the AC ductwork and the engine needs on acceleration. Since he doesn't have it, there's no throttle plate closure and the vacuum stays active, sucking gas from the carburetor. What a clear explanation! Well done!

This one might help point to which valve is stuck open or closed.

TBird, I have the 1979 Factory manuals in PDF format. Huge files, but I can parse out the Carb/Vacuum section into MS Word and send that to your son's IPOD?

Excellent post, Junk. You've created a spark.

 

A couple of thoughts from yrs past.
51 Chevy had a slightly warped crankshaft. Just bad enough that it would'nt start when hot.
Lived with it. I was young and dumb!
65 Chevy with headers. to much heat on the starter. That locked it up till it was cool enough to start again.
Made heat shield for starter.
70 duster 340 had an resistor on the firewall that would heat up and keep power from the starter till the resistor cooled down.
Bought new resistor.

 

All good ideas but:

1. The throttle plate closed all the way.
2. The carb is adjusted to spec except the float is adjusted a bit low which does not affect drivability.
3. All vacuum lines are correct, in place and functional.
4. The hard start is a flooded condition after 20 minutes.

The engine cranks just fine at all times. It will start but requires cranking for about 10 seconds and results in a big puff of black smoke. Thus why it's a flooded condition.

The carb is getting hot after the engine is shut off from a full operating temperature.

The discussion is about why is it getting hot?

Is it:
1. Normal and only because of ethenol in the fuel resulting in a lower boil temperature for the fuel? California is using 5-8% content of ethenol.

2. It's hot because of an exhaust restriction?

3. It's hot for some other reason not yet discussed.

 

We don't really know how hot is hot?
Leaky needle valve is something I'd suspect if the engine isn't all that hot.
I have never had a carb boil over and I have run my engine hot.
Like as in the temp guage pegged all the way at highway speeds.

 

Hey, wait a minute! Mine was acting up because the accelerator pump adjustment wasn't right. It would take about 4 or 5 tries and pumping the pedal like crazy to get it to run. After I set it to carbkit specs, it started just fine. Two little screws hold a metal cover on at the top and front of the carb. Set that and see if it helps. Especially if you changed the jet.

 

Mine starts great in the cold. It only has a problem 20 minutes to an hour after driving, then it has the flooded start problem.

 

I guess my 85F weather is cold for you. This was a summertime issue for me. Andy did a bit of tweaking for me, and all went well after that.

 

Ok, for the first person that actually solves the problem....they can buy the car for $2,400.

 

For the last several weeks smart a$$ it's been in the 20's in the morning and only today gone over 60F. It starts right up in the cold.

 

Sheesh! Why so low? The Carb is worth that in Mystery value!!

El Nino isn't particular is he? That's cold for you guys. Anyway, when it was 85F in July, the car acted up. How's that?

 

It soundsd like what my Datsun is doing. Once I get it started it runs fine. Mines a cold start issue BUT it could be the same issue. Which carb are you running??? Is it the motorcraft 2bbl that looks like a weber??? If so check for leaky jets in the bottom of the fuel bowl. That's what my weber seems to be doing.

 

Actually it's the Motorcraft 1 barrel. I took it all apart and no leaks. All the plugs are solid.

I did advance the timing to 12*BTDC and it's better. I'm going to go to 14* and see if that helps more. My gas milage is back up to 18+ around town now too.

Of couse I'll have to reset it back to 12 for emissions check next fall. I'm allowed + or - 3* from the factory setting of 10. One of the tricks to get a cleaner emissions check is to retard the timing a bit. I ususally set it at 8* for the test. It lowers NOX and HC to be a bit retarded.