Hot engine, flooding carb

[jamyers]

I've searched the forum and came up empty, so here ya go:

Stock 200 w/ electronic ignition and a good 2nd-hand ponycarb Autolite 1100 carb. Stock 195-degree thermostat and 6-blade fan (has a/c). The heater hoses bypass the hot-water spacer/adapter, nothing going through it.

The Ranchero starts and drives like a champ, except when the engine gets a bit heat-soaked, like on a not-cold day when I'm running errands and I shut it off for 5-10 minutes. When I come back out, the temp gauge shows 205-210 degrees, but it drops down once the engine is started and coolant circulates. Nothing that it hasn't done for years and years...

Only thing is, the carb acts like it's boiling fuel. It'll stumble and sometimes just die, lacks power, and generally drives like cr&p until I can get it moving and cooled down. If I keep my foot in it and keep the revs really high, it's "driveable", but the clutch isn't gonna like it for long. Not to mention it's a pita having it try and die at every intersection. When it floods and dies, restarting it takes a lot of cranking with the throttle wide open, and there's a TON of black smoke.



Tonight I checked the fuel pressure (rock-solid 6psi), and opened up the carb. Clean as a whistle inside there. Everything inside looks just perfect.

I'm out of ideas, you guys got any?

 

[BIGREDRASA]

Off-hand, 195* is mighty hot for Texas. Pull out the thermostat, and see is it still happens. If it clears up, try a 180* or 160* (Summer stat). Do you need the heater that much?

One other thing, take the airhorn off the carb, and see if it has a plastic float. Plastic become porous and tends to sink when left standing. If it does, replace it with a brass float, which will last forever.

 

[fordconvert]

An easy thing to try to see how close you are on temps is to pop the hood open a bit when you think this is going to happen so there is some room for the heat to get out around the edges. One of my cars had that same problem so I ended up installing an electric fan on a timer and letting it run for about 10 minutes. Worked for the last 7 years. Do you have some sort of alcohol blend in your fuel down there? That is what did it for me, If I went out of my way to find real gas it was fine but that 10% blend was enough to put things over the edge.

 

[BIGREDRASA]

That is what did it for me, If I went out of my way to find real gas it was fine but that 10% blend was enough to put things over the edge.

So true. In cold weather I can use Ethanol. It doesn't seem to be aproblem with FI, except for the lower MPG. It does have a higher octane. In hot weather Ethanol is almost sure vapor lock. However, what I said about the float still goes. The Ethanol just seems to make the plastic floats even more porous.

 

[BUZZ]

I had a similar problem, when I killed the engine and came back it would show about 220* on my temp gauge, so I bought a eletric fan. In the end what worked out best for me was to turn the fan unside down, because its thermostat was at the top and would shut off as soon as the top part of the rad cooled and I have it to where it will run even after I turn the key off, so now when the motors hot it'll usually run about 5 min. after I walk away, but I haven't had any problems since

 

[jamyers]

Brass Float, confirmed no leaks.

Thermostats: I swap t-stats in the summer/winter...a 180 just doesn't make enough heat for the heater to work worth a dang. Summers I use a 160. This started in the Fall, when I had a 160 t-stat in there - whenever it got over 205-210 it'd start acting up. It actually got cold enough for me to swap to the winter t-stat...as long as the engine stays below 205-210 it's fine, but it's now getting warmer. Even with a cold t-stat, running the a/c on a hot day WILL generate enough heat that it's going to perk, especially running errands around town, so I really don't think a cooler t-stat is going to fix it (besides, thats too close to a bandaid or a 'turn up the radio' solution for me.)

Fuel? I've tried switching gas stations, Fina/Shell/Exxon/C-store and haven't noticed any differences. Just simply everbody's "winter blend"???

Electric Fan: I'd add one if I could, but between the hook latch bracket, the a/c condenser, and the water pump face there's just not enough room fore or aft of the radiator.

I've even thought about hooking the heater hoses back up to the carb plate, maybe that'll actually cool it off.

I appreciate the ideas, keep 'em coming! I can't help but think it's something dinky that I just haven't thought of...

 

[Bort62]

Are you certain its a fuel issue and not an ignition issue?

 

[bigcatchdaniel555]

Never say never about the elctric fans Ive got everything you have and dual electric 10" fans on the left and right corner of the condesor it helps keep the temp down a lot. If you have pertronix definetly make sure thats not at fault. I had that problem with points and pretronix. Duraspark is great I only have somethin similiar if I'm sitting in traffic for a log time on a hot day when I go to take off the car will stumble it will start right away but once I move 5 feet its fine again.

 

[SteveS]

In my case, 82 Cougar wagon 200 six with full operating smog equipment and a 1946 the only solution was to lower the float about 1/8" below spec.

Pretty much all summer we are 100+ degrees.

This was the only thing that fixed the carb boil over when parked for a few minutes.

 

[jahearne]

What about the choke? is it an electric that closes once the coils cool off, but the engine is still hot.

 

[BIGREDRASA]

In my case, 82 Cougar wagon 200 six with full operating smog equipment and a 1946 the only solution was to lower the float about 1/8" below spec.

Pretty much all summer we are 100+ degrees.

This was the only thing that fixed the carb boil over when parked for a few minutes.

Amen to lowering the float. Try going down 1/8". That means up when the airhorn is upside down. The coil can also heat soak. I had such a problem, and only verified it by pouring cold water on the coil. 8)

 

[FalconSedanDelivery]

6 psi is a bit high for normal driving with a 1100 , 4-5 is plenty , Id put a regulator on it and adjust it down

 

[jamyers]

Ignition: DS distributor triggering a GM HEI module mounted on a gigantic heatsink near the brake master cylinder. Coil is a MSD Blaster 2 that doesn't get hot to the touch. Pretty sure the ignition isn't the culprit, but I'll doublecheck anything at this point.

Manual choke, all the way in/open 8)

I thought the stock fuel pump and carbs were supposed to run at 6-8psi, that's too high?

I'll try lowering the float height 1/8 inch and see.

 

[Anonymous]

When I had my mustang it would heat up and sometimes sputter and die. This turned out to be an ignition problem though.

Got a new dizzy, wires, plugs, coil, etc. and it was as good as new.

 

[Bort62]

The GM ignition modules are super sensative to heat. Are you sure you have a good thermal connection to the heat sink ?

 

[jamyers]

The GM ignition modules are super sensative to heat. Are you sure you have a good thermal connection to the heat sink ?

Pretty sure - I used the good grease/pooky between the module and heatsink. But I'll doublecheck it just to make sure - good point.

 

[LaGrasta]

Be sure your choke is staying open once warm. It almost sounds like it's being choked when it doesn't need too.
How is your choke operated, manual or electric?

 

[BIGREDRASA]

Don't forget to lower the float. A leaking needle valve or float set too high will give some of the symptoms you describe.

 

[jamyers]

Manual choke, all the way in/open.

It'll be thursday night before i have a chance to tinker with it, but I'll report back asap.

Thanks!

 

[BIGREDRASA]

Manual choke, all the way in/open.

It'll be thursday night before i have a chance to tinker with it, but I'll report back asap.

Thanks!

Any progress?