Vapor lock

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EL5DEMON340

EL5DEMON340

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Now that I have a 6 pack on my car when it sits hot for more than 10 or 15 minutes it is hard to start, guessing it has to do with all that mass because I didn’t have this problem with a 4bbl. I run a electric pump so no problem when driving. Can I replace my regulator with a bipass regulator and run a 5/16” line along side my 3/8” supply line, then dump it back into my tank via the sending unit 1/4” port? Or is there a better way? The heat crossovers are blocked. Thanks
 
Have you checked the power valve, and is it the correct one?
 
That is possible. What valve do the tuning specs call for and have you experimented going up or down, or putting a block off in place of the valve. Years back when I ran a 340/6 4 speed car on the street, it was a constant tuning event. This was because the car was my DD, but was raced on the weekends. I know technology has come a long way since then, I'm just adding .02.
 
I do not advocate a clear fuel filter, but they can be useful in diagnosing things like this, if it is vapor lock it will have no fuel in it.

also when restarting after the 10 to 15 minutes try not pumping any additional fuel into the manifold but hold the throttle open about 1/2 while cranking.


I had a situation where with my stock 273 2bbl the engine would idle then the idle speed would fall off then pick back up. At the same time I could watch the fuel filter go from full to empty then just as the speed fell off it would fill again. Also when the engine was particularly hot from sitting in a fast food line, when I hit the street I had to be super easy on the gas or it would stumble, after a minute of driving it would be fine. I suspected the alcohol in the fuel so I tried non alcohol fuel and all the problems went away and I can not make it happen any longer. i did not change any line routing or add insulation etc.

I fixed both issues by using non alcohol fuel ( Pure-gas.org - ethanol-free gasoline in the U.S. and Canada )
 
When you do finally get it started , can you determine if it was flooded, by way it runs? (chugging/some black smoke) This will be able to tell you what's going on, to a certain extent. Maybe one of those carbs is overflowing or something similar.
 
cudavert said:
When you do finally get it started , can you determine if it was flooded, by way it runs? (chugging/some black smoke) This will be able to tell you what's going on, to a certain extent. Maybe one of those carbs is overflowing or something similar.
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Once it starts it’s fine, it does have a MSD. It doesn’t really chug or blow smoke out.
 
Take a look at your choke when it happens, I have 360 with 6 pack that I recently put on my 65 barracuda and my heat crossover is blocked as well. Sometimes when it’s hot and you pump it the choke will still slam shut and cause hard starting. I was told with those crossovers blocked the choke will not function correctly. I plan on fixing it just been to lazy to deal with it.
 
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