carb guru ?

[Rox Crusher]

Do we happen to have any carb gurus in the group ?

On my F150, I have an Edelbrock 1407 which appears to be this 750 cfm with manual choke.

http://www.jegs.com/i/Edelbrock/350/1407/10002/-1

I thought it was vapor locking as it would quit running anytime it (1) was above 65* ambient and (2) the engine was at operating temp. The crappy after market gauge would read 205* as quickly as 10 minutes of running.

When I first got the ol girl I had the fuel pump and fuel filters replaced "just cuz". When spring (last spring) came around is when it first started leaving me stranded. When this happened I would generally have to wait 15 or 30 minutes for it to cool down and be able to start & run again. I don't drive it much so I just lived with it through the summer.

I have done plenty / had plenty of things done to it trying to resolve it, most of which I believe needed to be done anyway;
- replaced ignition box
- new fan clutch
- new plugs, wires, distributor cap
- new radiator (original one was leaking and weighed at least 80 lbs from all the shiot in it)
- new 180* thermometer

Recently it has been getting worse but could generally be restarted by squirting a good amount of fuel into the carb after it cooled down a bit. But it also was indignant enough to quit running even before getting up to 100*. So I dropped it off at a nearby shop and told them I thought the carb needed some work.......but they decided to throw an electric fuel pump on it as I had apparently said "vapor lock" one too many times. This helped, but didn't solve it.

I don't know the first thing about carburetors but am absolutely convinced that this is the real problem and whatever is wrong is getting worse.

I am hoping to have someone knowledgeable look at it, tune it, smack it with a hammer, replace it with a better one, something, anything..................but not wanting to spend precious hotrod money converting it to EFI.

[71 Broncman]

I've been dealing with the same issue on my 75 HiBoy for about a year and a half now. I have an Edelbrock 1406 (600 cfm) on a cast iron intake and headers. The vapor locking co-insides with the mandate to leave the ethanol in gas year round. I had insulated my fuel lines about 20 years ago and never had with vapor lock until then. Some of the issues are; ethanol boils at lower temps., ethanol absorbs atmospheric moisture, ethanol has less energy output than pure gas, and it tends to corrode the inside of an aluminum carb if left sitting for any length of time.
The things I have done to combat the issues have been kind of incremental but here is what I've done to remedy the problem.
Re-routed the fuel lines to the outside of the frame rail.
Insulated the lines with heat sleeve from the frame rail to the carb.
Placed a 1/2" isolator under the carb.
Cut Run Cool hood vents into the hood to vent built up underhood heat.
Put spacers under air cleaner (14", drop base) to keep heat from being trapped around carb body.
I also put 6 oz's. of Lucas fuel stabilizer in at every fillup to counteract the ill effects of the ethanol.
I am going to install a regulator to get the fuel pressure going into carb down to around 4 1/2 - 5 psi and see if this helps because Edelbrock carbs only like 5 1/2 psi max. The Carter mechanical pump I have puts out about 7 psi.
All totaled this has made the truck fun to drive again because I don't have to worry about sitting on the side of the road with the hood up waiting for it to cool down enough to start.
Some things for you to consider. Hope some of this helps.
Mark.

[Rox Crusher]

thank you Mark, some good info there

I forgot to mention that when the shop installed the electric fuel pump they also rerouted the fuel lines away from the dual exhaust and the engine

[ZOSO]

I did most of the same things on my 79. Only thing I did differently was a different fuel pump that put out 14psi. Then about a foot from the carb ran a regulator that dropped it down to 6psi. Higher the pressure the higher the boiling point. It worked great and I never had issues after that.

[71 Broncman]

One other thing I forgot to add was installing a tank vent. My truck never had one so I picked one up at the JY. Venting the tank helped a lot as I would sometimes get a about 10 psi of vacuum built up.
Mark.