6 Pack Issues

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Eddie348

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Good afternoon. Experiencing a vapor lock after waiting in a drive thru line - Looking for advice on what to do to avoid or someone in the Chicago area that can assist. Mechanical set up on a 69 Dodge Dart GTS. Thank you in advance

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Are you running a mechanical fuel pump? There are threads on here that discuss using a fuel filter with a return that helps. Use the search function.
 
Good afternoon. Yes Carter M6270. Sure will. thank you

 
The engine was rebuilt - Ran great no problems until the 6 pack installed. Thank you
The easiest solution is to pull the six pack back off and send it to me.

I am running a tanks Inc. in- tank pump with a regulator and return line to the tank. It works great.

I think the simplest solution would be to try the filter with a return and make sure all of your fuel lines are away from heat sources
 
Either put an electric pump on it and run a return line, OR a mechanical pump with enough pressure to stand running a return line. The return line and higher PSI pump will solve the issue.....that is IF it is really vapor lock. I've said this many, many times, but real vapor lock is pretty rare. In fact, I'd be skiddish to make that diagnosis for you, because of the type of fuel hose you are running. Even though it has steel braid over the rubber fuel hose, that's still an extra layer of insulation, however poor steel is for an insulator.
 
The other thing I would try is run the fuel lines separately to each carb. That’s how the factory did it. Not sure if that would cause it or not but for most of the time, you’re only running on the center carb.

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The other thing I would try is run the fuel lines separately to each carb. That’s how the factory did it. Not sure if that would cause it or not but for most of the time, you’re only running on the center carb.

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Eh......"sorta". They had a main line from the pump to a "fuel log" with two tees. Kinda what he has, with the individual lines eliminated. They still all had fuel at the same time. Keep in mind too, he's manual, not vacuum. His has accelerator pumps on all three carburetors and I'm pretty sure he's running 1:1 linkage, so they all open at the same time. The stock setup looked like this....but I'm sure you're familiar with it.
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Eh......"sorta". They had a main line from the pump to a "fuel log" with two tees. Kinda what he has, with the individual lines eliminated. They still all had fuel at the same time. Keep in mind too, he's manual, not vacuum. His has accelerator pumps on all three carburetors and I'm pretty sure he's running 1:1 linkage, so they all open at the same time. The stock setup looked like this....but I'm sure you're familiar with it.
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Yes, you are correct about the fuel lines and accelerator pumps.
But, I’m not sure what his linkage looks like. What I have, I believe it’s the factory setup, not 100% sure. Is adjustable so you can have the outboard carbs come in when you want/need them. Also the outboard carbs on mechanical setups do not have mixture screws like the vacuum carbs do. Only the center carb. It has a metering block with the mixture screws.

If it didn’t vapor lock before the six pack was installed, I would think it would be something in the change to cause it if in fact it is a true vapor lock.

Op, are you sure all carb adjustments are correct? Floats, jets ect?

There are some great threads on FBBO about six pack tuning. Very lengthy reads but worth every minute.

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All good evening. Thank you for all the great advise. Will a Phenolic 1/2 spacer also assist? Might be several issues here. Can a hot ign. coil cause it? Appreciate everyone
 
Yes, you are correct about the fuel lines and accelerator pumps.
But, I’m not sure what his linkage looks like. What I have, I believe it’s the factory setup, not 100% sure. Is adjustable so you can have the outboard carbs come in when you want/need them. Also the outboard carbs on mechanical setups do not have mixture screws like the vacuum carbs do. Only the center carb. It has a metering block with the mixture screws.

If it didn’t vapor lock before the six pack was installed, I would think it would be something in the change to cause it if in fact it is a true vapor lock.

Op, are you sure all carb adjustments are correct? Floats, jets ect?

There are some great threads on FBBO about six pack tuning. Very lengthy reads but worth every minute.

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I tell you man, that factory setup was HARD to improve upon when it was tuned right. They'd suck up some asphalt.
 
All good evening. Thank you for all the great advise. Will a Phenolic 1/2 spacer also assist? Might be several issues here. Can a hot ign. coil cause it? Appreciate everyone
I wouldn't think a spacer would hurt. I think though, before the spacer, I'd use those thick insulating gaskets. That way you are eliminating the gasket "sammich" and eliminating all those gaskets where leaks could occur.
 
Thanks Rusty. I know you have been part of my journey with this build. Can you advise what gasket to try first. Wish there was someone nearby that I could get all of this fixed. It is a fun car to drive when it acts the correct way. Thank you
 
@coloradohill I believe everything was set up correctly. The set up was rebuilt and installed by Brian6pak (May he RIP). I have not done anything other than ensure the filter element is good. Thank you for all the great advise
 
@coloradohill I believe everything was set up correctly. The set up was rebuilt and installed by Brian6pak (May he RIP). I have not done anything other than ensure the filter element is good. Thank you for all the great advise
Although I never knew him, I’ve seen very nice things written about him and can tell he was well respected here. So, I also would think that is set up correctly.
 
The engine was rebuilt - Ran great no problems until the 6 pack installed. Thank you
After reading again, did you ever have the engine running good with the six pack installed?
The way I’m reading this is it ran good before the six pack was installed (no vapor lock).
So after the six pack install, did it run good until it vapor locked just recently?

Also after the vapor lock, what did it take to start it again?
Thanks
 
Eddie, first thing I'd do is confirm the vapor lock. Get an IR temp gun and shoot the fuel hose in several places. Then shoot the carburetor base plates and float bowls. If you think that those temps are too hot, here's my suggestion. See the red arrow. Remove that last banjo fitting and replace it with one JUST like you have in the front. Then, you can come off that, route that hose to a fuel pressure regulator and then come out of the regulator with your return line. I would also add a fuel pressure gauge between the pump and carburetor.
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Good evening. I have had 3 occasions of Vapor Lock (I believe) after the 6 pack was installed. Also installed a new accel coil when the 6 pack was installed. Nothing else. Car runs fine until it sits for a bit or it's hot outside. After 1 to 2 hours of it sitting the car starts up again.
 
Although I never knew him, I’ve seen very nice things written about him and can tell he was well respected here. So, I also would think that is set up correctly.
He was a great Man with a kind and good hearted soul. We spent a good time putting the 6 pack on.
 
Eddie, first thing I'd do is confirm the vapor lock. Get an IR temp gun and shoot the fuel hose in several places. Then shoot the carburetor base plates and float bowls. If you think that those temps are too hot, here's my suggestion. See the red arrow. Remove that last banjo fitting and replace it with one JUST like you have in the front. Then, you can come off that, route that hose to a fuel pressure regulator and then come out of the regulator with your return line. I would also add a fuel pressure gauge between the pump and carburetor.
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Rusty good evening. Any suggestions what fuel pressure regulator to use? Thank you
 
One other thing I have been doing over the years is to run the Edelbrock intake gaskets that block the heat crossover on the heads.
I’m now running Edelbrock heads without the heat crossover. Takes a little longer to warm up and idle but in the hot weather it helps a lot.
Looks like you have iron heads?
Might try the other intake gaskets if you aren’t now.
It’s a pain to change them but will help in the heat.
 
Rusty good evening. Any suggestions what fuel pressure regulator to use? Thank you
Probably this one. It's a good compromise of quality and price and it has the 1/8 port for a pressure gauge. What fuel pump do you have?
 
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