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zero

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Discussion starter · #1 ·
recently i dropped in my carb'd 351W into my fox. i keep having the same problem and noone seems to know the answer. the car runs fine.. drives like a dream.. but when i come to a stop or let it idle for too long, it just shuts off. most of the time it takes waiting a few minutes before i can start it again. i had thought it was a cooling problem and bought a two core radiator and a 2500cfm electric fan. it stays between 190 and 170 generally speaking and everything else seems to be performing well. just every time i come to a red light and im letting it idle, it boggs down a bit, returns to idle, boggs, returns, and then shuts down. i have no computerized sensors to shut it down in the case of low oil or its running too hot. i hope someone can have an answer for me. or if anyone is in the cherry point area of north carolina and would like to take a look..
thanks
 
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Discussion starter · #3 ·
it idles about 800 and dies when it hits about 500-600 when it boggs the first few times it only dips to about 700 usually
 
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Discussion starter · #4 ·
bump
 
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#5 ·
Sorry I don't know anything about carb setups but it sounds like vapor lock. Sitting still and stalling and the wait until you can restart is the major indication of this.
I know there are several methods of venting the fuel chamber to reduce the effects of vapor lock.
If it is vapor lock, you would need to figure out of it is happening before the fuel pump (from the sucking action) and is the vapor being passed down the line from there or is it happening in the at or near the lines at the carb. Is your fuel pump at or near the tank? If so, I would assume the source of the vapor is closer to the engine from localized heating or poor venting. Again, I know nothing of carb systems, my thoughts are based on things I remember from a long time ago and not from practical experience. There were no replies to your problem so far so I thought I'd give it a try.
 
#6 ·
+1 on the vapor lock, good call.

If it is vapor lock some simple things you can try: rerouting the fuel lines away from any possible heat, using header wrap on the headers (or another heat source) to lower engine bay temp, and possibly insulating the fuel line.
 
#7 ·
I'm not a big expert on carb setups either but what kind of carb are you running? I know if you have an after market like Holley, or Elelbrock and you get them too big you tend to run really lean. If its a really high CFM rated carb and you aren't getting enough fuel and all that jazz to your engine, that could cause it to stall out.
 
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#9 ·
Are you running an electirc fuel pump... The PSI may be too high and pushing past your jets. This in turn causeing flooding.. Also take a look inside the carb (when it is off) and give the trottle a little squirt. Watch to see if the gas sprays in or if it puddles in. Is this carb a used carb or brand new and what kind?
 
Discussion starter · #10 ·
the carb is a holly 600cfm. the car is running a bit on the rich side, and im not worried about that. however, im more apt to think its vapor lock of some kind. even while driving sometimes it shuts down... generally thats when im going slower.. and i dont have a carb spacer, and im thinking im going to insulate my fuel lines.. would having a half inch carb spacer make that much of a difference in the heat absorbed by the carb? i am running an electric fuel pump.. however ive got it set up to give me 6psi at the carb. the carb was brand new when i bought it last year, and never went into service untill about january of this year.
 
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Discussion starter · #11 ·
bump
 
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#12 ·
Whats with the bump thing? WTF does that mean?
 
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Discussion starter · #13 ·
it means im trying to keep the topic on the front pages so people will look at it and reply.. because id really like to be able to drive my car and not worry its going to shut off at the wrong moment.
 
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#14 ·
Sometimes it can be very hard to tell people what their problem is...Hell i know that some people can't tell you anything unless they are right in front of it. And in my case, I don't know what is going on at all...Worst case scenario, take it to someboy and ask WTF? The pros should be able to work it out. Good luck man.
 
#15 ·
zero said:
it means im trying to keep the topic on the front pages so people will look at it and reply.. because id really like to be able to drive my car and not worry its going to shut off at the wrong moment.
Click to expand...

Oh ok...
 
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#16 ·
Buy a heat shield. Holley makes them and Summit sells them. They are cheap. The heat shield goes under your carb and keeps heat off of the fuel bowls. Most likely it is a heat issue under the hood. Whether it is heat getting at the fuel bowls or the lines, I don't know without physically having the car in front of me. I'd be willing to bet this problem would not happen if you had the hood open.
 
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Discussion starter · #17 ·
would a carb spacer do the same thing? after i read that, i went out to my engine and noticed that yeah the carb is pretty warm.. so im going to give that a shot.
 
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#18 ·
I doubt it is your carb. Your motor would have to be running extra hot to get your carb to hot. The carb gets hot. Next time it happens check to see if you got fuel in your float bowls. If you got fuel in your float bowls when it dies, then vapor lock is not happening. If no fuel, may need to re rout your fuel lines. But I bet you have fuel in it. It is probably a spark problem.
 
Discussion starter · #19 ·
why would it be a spark problem if its consistently happening when the engine warms up? i get what youre saying about the carb getting hot, it sits on top of the engine, its going to get warm. but i can almost say 100% that its not spark. i had gone that route a month ago.. changed everything, the coil, the points to hei, the wires, the plugs.. everything included was changed. the car will idle forever untill the temp comes up to about 180-190.. then the idle struggles and before long the car will shut down. when i try to start it, it just spins and spins. if i sit there for anywhere between 1 and 10 minutes with everything off, the car will start.
 
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#20 ·
Could be something odd. But like I said, check yur' floats.Your air/fuel ratio may be off. Usually once warm, it allows it to be off more so than cold. You would know if it was engine mechanical probs. Check your vacuum stuff too. Make sure nothing is comming loose, or slit.
 
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ryanw
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