Can't shake vapor lock issue!

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1mopar4life

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My 74 Dart has a mild 318, factory rad/fan, electric fuel pump and I keep having what seems to be a vapor lock issue. After driving and bringig the car up to 190 degrees it will die in gear at stop signs. It had the Charcoal canister removed and that line was crimped. I have the gas cap drilled for a vent which helped some. I have a 600 Eddie carb and single plane Eddie Troker 2 340 intake. The base of the carb is cool, the fuel lines are run as best away from the headers as possible and it still dies. I have the timing set at 0 on the balancer, where should it be at exactly? I have a timing light and checked my timing with it. Do I need to open the line that originally vented the tank back up? It runs fine at any time and any gear except when stopped at a stop sign waiting on traffic, it is a 904 Auto car as well. Thanks for y'alls help as always!!
 
Is the float bowl vented?
 
That's a good question, how can I tell it is? I may put one of my Holley's on it and see if it helps any.
 
I would start by bumping the timing up, but check your total advance if you are running a stock "smogger" distributor

My favorite thing is a vapor return system, and since you have eliminated the carbon can, you can use the 1/4" return line for that

Just get a Wix 33040, 5/16, or 33041, 3/8, or a 33054 which comes out at a 90.
You just hang the filter with the 1/4" fitting up, and run the 1/4 fitting back to the tank.

Where is your fuel pump mounted?

Are you running any insulator spacers under the carb?
 
I am going to go out on a limb and say the dizzy isn't a smog one. My fuel pump is mounted right at the tank away from the exhaust pipes. I don't have any spacers under my carb but it doesnt get hot, you can put your hand at the base of the intake and it isnt hot even after the engine has been run hard. I am running around 1100rpm in neutral and 700-800rpm in gear at idle.
 
Plugs were a light tan but now my water pump, oil pan, trans pan and rear end are all leaking so I'm just walking away from this project for a little while before it ends up in the classifieds! I can't seem to make it idle up much from 700-800 in gear no matter how I adjust the carb or timing.
 
How new is that Edelbrock carb? Is it the old Carter AFB style?
 
Had the same problem with the totally stock and very tired slant in my Feather. Started dying about half the time when you slowed down for a stop light.

Thought about raising the float level, but never got around to it. Kicking the static timing ahead to the spec on the fender sticker and richening the idle half a turn did the trick.

I don't understand the need to modify the tank venting system, even at just under 300K the tank venting system and charcoal canister are in place, and work just as God and Mother Mopar intended.
 
I have had luck splitting a fuel line and putting it over the metal part of the fuel line to insulate it. We have lots of vapor lock issues at this altitude and (after everything else is set right) this always does the trick.
 
I insulated all my fuel line from under the car up to the carb and still vapor lock action occurs. Even with the fuel cap off it still has the same problem. Im beginning to think my pump is junk, filters are stopped up or something to that effect but that doesnt make sense to me because it always runs well at any rpm over 1200 and doesnt miss or seem like its leaning out at high RPM. If I hang onto this car much longer I am going to put a new tank, sending unit, fuel lines and a new vent in it. The tank isnt in great shape but it worked great until we tore the car down for the suspension swap. Its the strangest thing Ive seen!
 
The tank may have gotten bumped when doing the suspension work which could have knock some of the old gunk down and got sucked up I'm taking it's the original tank. Just a thought being it started after you did the rear end stuff.

Good luck figuring it out and let us know what you find out. It might help someone else.
 
Im going to change the fuel filter at my pump as well as get it to do the die at idle and see if I have fuel pressure. I don't see why it could lose pressure only at idle.
 
Wow, a lot of tailchasing when the cause of the problem (or at least a very major contributor) is right there in the first post in the thread:

It had the Charcoal canister removed and that line was crimped.

That was an unwise thing to do, whether you did it or a previous owner did. Read up on how to put it back together the way it's supposed to be, uncrimp/repair the hacked line and hook it up right, then put the correct (undrilled) pressure/vacuum fuel cap back on and see if your problem doesn't go away.
 
I opened the crimped line back up and it still does the same thing. It is indeed venting the tank as it should from that line but still no change. I have another fuel filter to put on tomorrow. If this doesnt cure it, a full fuel system replacement is going to be in order with a mechanical pump, new lines, new tank and sending unit.
 
Throwing parts at it is unlikely to do much except drain your wallet, especially since none of the parts on your newest shopping list is causing the problem.

My suggestion wasn't to just uncrimp the line, it was to fix and unhack the charcoal can system, including the carb bowl vent and purge provisions.
 
I disagree with all the bawlin 'n hand wringin' over carbon cans. Yes they work when hooked up, but sounds like yours is really really hacked.

First, your cap is NOT vented. It should say "pressure vacuum" and that is more of a positive/ negative pressure "pop off" NOT a vent.

You need to get back there WITH A SHOP MANUAL and look over the "can" in the rear where all the vent lines converge from the tank, and make sure that is all hooked up, and replace the rubber lines for deterioration.

IF I were doing this, I'd add the original "pre can" style vent, which is a tube brazed into the filler up high just inside the trunk. This then goes into an "upsided down U" and goes back down along the filler tube through the trunk seal, and ends (open ended) into the rear frame rail, where it can drain if overfilled.

Alternately, maybe braze a line into the TOP of the rear vent can and run that up as high as possible, then back down as the original did.

PLEASE consider adding a vapor return system as I mentioned. THEY DO WORK end of story. You can use your original front -to- rear 1/4" line for the return, but some of these had a check ball up front. You can recognize it by an odd "crimped looking" section in the first couple of inches. Just cut that off.

What I'm running on my mild 360/ headers

Red pump in the rear, to mechanical pump. The mechanical may go away

Inexpensive spacer about 3/8 under the carb. If I'd done this over, I'd have plugged the head crossover. Edelbrock 600

Wix return filter 33041, plumbed to 1/4 " return line.

This has eliminated almost ALL my starting problems. On a hot soak in the sun on a hot day, it might spin the starter for 5 - 8 seconds.

I get in, turn on the key to run the pump a few seconds while fastening my belts and shutting the door. So maybe 10 seconds of "pump time." This gives the pump time to flush vapor out of the front line, build up "clean" pressure, flush heated vapor/ fuel out and fill the carb bowl.

Regardless of what Danny boy would have us think, the engineers weren't always thinking of "our best interest" Pinto's n Vegas are proof of that
 
After it is warm and acting up, try starting it and manually closing the choke to see if it makes a difference. If it does, rev the way up then close the choke all the way until it dies. Sometimes that will suck junk out of the idle circuit. You can also try pulling the idle enrichment screws out and gently blow come compressed air into the holes.
Also look in the distrubutor and make sure the weights aren't sticking advanced when it gets warm.
 
I had this happen to me and it ended up being the pick up coil or ignition box, I can't rember or I might have replace both. Would lose spark at low RPM
 
wow your still chanceing this I would be have to agree with the other try the coil if it only does it when its warm
 
I have zero factory parts left of the canister or anything close to it other than the metal line from the tank to under the pass side door. Im going to find a better mouse trap than the crap from the factory. My big block pickup vents only from the gas cap and has never Pinto'd so Im going to make it happen that way if all else fails. I did go to mechanical pump which helped a ton but after playing with the carb, we've found its a POS. I wont have another Edelbrock on a vehicle. I am looking for a 600 Holley right now to put on it. It is venting, the intake is cool, its got fuel pressure, the lines are insulated. Its not a vapor lock issue, its a carb that is about a 1000 years old and needs rebuilt or used as a paper weight issue.
 
I ran Seafoam through the carb and then put the other half in the tank and ran the crap out of it after it got up to operating temp. Ran extremely well, ol 318 pulls alot harder with the different fuel pump and having the carb set halfway right. Ran around town after that and had no die at idle issues. We'll see if it keeps running good. Even with 2.46 gears, itll finally boil the tires!
 
The charcoal cannister has nothing to do with your problem. It is a primitive pollution control device that was marginally effective when new and becomes basically worthless after it gets gas soaked and plugged in a few years.
 
Thats what I've come to believe as well. My issues are stemming from the carb being old and more than likely gummed up. I am looking toward upgrading the ignition system or at least replacing the old parts with new ones to add another bit of preventative maintenance. I've had this car for close to a year and just now getting close to enjoying it!
 
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