Diagnosing a Potential Fuel Problem

>The cold-start is probably a combination of choke adjustments, a lean low-speed circuit,lazy timing, and/or operator error.
>The engine not liking to run until the temp comes up, is either a lean AFR, or lazy timing or a combination. I have noticed that aluminum heads and the AirGap do take a bit of warm-up time, but a fat low-speed circuit solved it for me.A direct drive fan may aggravate the warm-up time.The cold engine likes a ton of advance. I give it that thru the vacuum advance can,using ported vacuum, and the fast-idle cam to activate the circuit.
>The stall on the corner sounds like fuel slosh, and the long crank time kindof proves it.If the fuel ends up in a corner of the bowl, and the float drops, BAM!, the electric pump will over-fill the bowl in a heartbeat.
>6.7mpg! You actually checked it?! Wow, that does seem excessive. First I would examine the entire supply line for leaks.Then I would pull the dipstick and make sure the fuel is not ending up in the pan. If no leaks are found, you have two choices;1) get an AFR gauge, or 2) empiracle testing. The first circuit to undergo testing is the one you spend the most time on. But in all likelyhood, fuel consumption will settle down, as the novelty of the mighty stroker wears off,lol.
> as to carb size; Performance sucked on my 367 with a 600 vac carb. It was better with a 750 vac carb. It perked up quite a bit with a 750DP. It is 100% street driven.I really liked the TQ, and the TQ really liked the 367. But I wanted the AG, and I had accumulated all these carbs, so I went on a testing spree. I must admit, the 600 can make amazing point to point mileage. Someday, I'd like to test an 850DP!
>The CFM formula says a 750 is right for my 367 to 7000rpm. The formula says in a stroker,a 750 is good to 6200,and 850 is good to 7100.
That same formula says a 600 is good to about 5600 in my 367. I don't think so Tim. That 600 was good for fuel-mileage and banging around town and nothing else. The 750 is plenty for me,I guess,lol.
> I'm not a big fan of electric pumps.
The engine doesn't care how much pressure the fuel comes in at, as long as the pump does not overpower the float valves.The float level is only slightly affected by fuel pressure in the normal range,so long as the pressure does not exceed the valves ability to regulate.The low-speed circuit is the one that is most affected by a fluctuating fuel level.But even then it is a minor thing.
You can see this in action, by killing the pump on a warm engine, at idle, and waiting. One of three things will happen;1) if the fuel level is just right, it will idle normally for maybe 15 seconds, then begin to slow down,labor,and eventually stall,or 2) If the fuel level is too low, the engine will immediately lose rpm,labor, and stall,or 3) if the fuel level is too high, then the idle speed will slowly rise, level off, then begin to drop,labor and stall.
> personal opinion, but I think that fuel system is wanting a fuel-return.