[64speed]

Well I got the vented gas cap so I am good

[Tom Vaught]

Not true at all, you ASSUME that you are good. A vented gas cap will flow no where near the air flow that a simple 1/4" or 5/16" (inside diameter) line will flow. If the vented cap, by itself, would work, why do Tanks, inc and Aeromotive have dedicated vent line connections on their fuel systems.

Keep on assuming and you will continue to spend money to find what is wrong.

Tom V.

I wish you luck on your investigation.

[64speed]

Well if I install the new gas tank will it not be vented?

[Boostedbird]

You haven't answered anyone's questions and probably haven't tested anything that was suggested. It would be easier and quicker if you would try to use the help that you asked for. It's really easy to test the tank vent. Just drive around some with the gas cap off or loose. If it fixes it check the tank's vent line.

[64speed]

I did try several of the options that were suggested as well as trying a few of my own. I looked for hidden filters. I drove around without a gas cap. I put a vented gas cap on. Just because I didnt give you a blow by blow doesnt mean I didnt follow the advice.

["QUICK-SILVER"]

Originally Posted by 61-63

If you haven't changed your rubber fuel lines from the end of the metal line to the tank and on the other end from the end of the metal to the fuel pump, try changing them. A pin hole leak in one of those can cause the fuel pump to pull air on and off and cause what you are experiencing. I had a friend who had that problem drive him crazy and putting a new line from the tank to the end of the metal line finally fixed it for him.

Seen that happen a few times. Car would stall or quit with no regular pattern to it. The rubber hose, between tank and chassis, would suck air in but not leak gas. There was enough restriction on the sock (pickup screen) that the hose would try to colapse and open up a crack or pin hole.

Trash in tank or stopped up sock (in tank pickup screen) causes restriction. The restriction causes extra low pressure (vacuum) in the fuel line between tank and fuel pump. Fuel will boil at a lot lower temps under the vacuum situation causing 'vapor lock'.

One of the most aggrevating cars I ever worked on, that had a random stall or starve for gas, ended up having a CONDOM in the gas tank. It would work it's way onto the sock and then fall off after the engine died and the fuel pump quit sucking.{this was not funny}

With the low boiling point of modern gas, heat from exhaust pipes, restriction between tank pickup screen/sock and fuel pump, and the fuel will boil causing vapor lock. These cars did this when they were new....So doing it now with the stuff that's called gas....is not uncommon.

A few minutes cooling off, dirt falls off the sock, lines cool off, air seeps in the tank from improper venting, etc... and the car cranks and goes on.

[64speed]

Thank you Quick-Silver for your thorough answer

[64speed]

Well I think inadvertently I narrowed it down to the fuel system. I cruised thru town yesterday and got gas and had zero problems (about a 10 mile trip) I came home and ran in the house and then ran out to go to my In-Laws and within 500 feet from the house it was stumbling. Now when I had been looking under the hood before I left I noticed the fuel filter was full and appeared almost perfectly clear with some minor bubbling every time the pump pumped. When it started stumbling I pulled over immediately and the filter was only half full with foamy looking fuel in it. I limped home and left it idling in the driveway until it smoothed out again and I took off again and again it did it. I limped back home again and left it idling until it did it at idle and when I looked at the filter again it was only half full and foamy. It has never done it at idle before, it has either ran or shut off. Well anyway I crawled under and it appears to have some kind of rebuildable fuel pump on it but I ordered a new edelbrock anyway so I am gonna replace the pump, tank, and ALL the lines. If that doesnt fix it then I will set the car on fire. Just Kidding.....kinda. Thanks everyone for the help

[STEELCITYFIREBIRD]

A condom!

I had one with some thin plastic that would suck up on the sock intermittently, plastic bag or maybe ciggy cellophane wrapper.

[Greg Reid]

First, a disclaimer...I did not read every reply to this thread so forgive me if I repeat something.
First step, determine for sure if it's fuel or ignition related. They both get worse as ambient temperature rises.
I had a very similar problem with an 80s era Dodge truck. It was fine in the morning (cool) and would cut out in the evenings (hot).
The way I determined ignition or fuel was that I drove it fairly hard up and down my road until it started cutting out. I immediately pulled to the side of the road, removed the breather cover and gave it a couple of pumps. Just bubbles. Definitely fuel related.

LONG story short, it turned out to be my fuel pump eccentric. I wasn't getting a full shot from the pump due to the bad eccentric. I never fooled with it, just installed an electric pump by the tank and bypassed the mechanical. Never had an issue with it again.

[pfilean]

I had the similar surging problem. Thought that after about 10 years I should replace all the rubber sections in the line with something newer. Old rubber line didn't look bad but I changed it anyway. At the same time I noticed a little seeping from some compression fittings that I installed this spring when I put in a primer pump. As had been mentioned, a little seeping spot can suck some vacuum and mess up a mechanical pump. Thought those compression were tight but I guess I was wrong. Anyway, with it all up tight and new rubber I have not had a problem so far. Will see again tonight. It's good and hot today so I'll see if that makes a difference.

[geeteeohguy]

Had the same problem in '88 on a trip to Yellowstone in my '67. Thought it was vapor lock. An in-line electric pump helped, but didn't fix it. Turned out to be a collapsed sock inside the fuel tank at the pickup tube. Cut it off and no problems since. Have also run into cracked rubber fuel line from the tank to the steel line. Doesn't leak fuel, but draws in air and the pump sucks air. Keep us posted.

[64speed]

Just when you thought the issue had died an update appears. Well its taken me some time but I got the fuel system portion of the rebuild done. The fuel tank is new, the fuel pump is a brand new edelbrock, it has all new metal lines and rubber lines from front to back and a new filter and carburetor. Still surges. Guess I should have done the ignition portion first. Anyway I was doing disc brakes at the same time. I guess I will finish that up and then install all the MSD stuff. If that doesnt work I am throwing an ignition switch at it for good measure. If that doesnt work the car will be for sale BAHAHAHAHA

[64speed]

If you havent read my previous post on intermittent surging please do so. Well after replacing the WHOLE fuel system the surge was still present on the test drive and I made it back to my house where it died in the driveway. Now it turns over and will not start no matter what I do. So I guess the only thing left to do is replace all the ignition components? Whats the average life of a pertronix unit? Could it have been slowly failing this whole time? Thoughts?

[TedRamAirII]

While its dead, check for spark. Take the coil wire off the distributor and see if spark occurs. No Spark? check the + of the coil while cranking car, Voltage? (use a test light) now put the test light on the - of the coil, should have a flashing light while cranking. Solid light? no trigger for coil, check distributor (points or otherwise) No Light? short between coil and distributor, or points/pertronix. If you have a Pertronix unit, it should be easy to put points back in for a test.

[400 Lemans]

Yeah i had the very same symptoms as you a few years ago with pertronix in the points distributor. Stranded a few times on side of the road. Car would just cut off while driving down the road. Then after a while i could finally get it fired back up. But one time it backfired and actually swelled the mufflers up. Went to an HEI and never looked back. Problem solved. No more pertronix for me.

[STEELCITYFIREBIRD]

Do you have good solid spark?
No experience personally with Petronix system.
A good friend with a 67 Chevelle had nothing but trouble from his, removed and replaced with alternate system, MSD I believe, and his car runs very well again, his was only in service for a year and minimal use.
With that...I'd determine the cause before replacing the whole ignition system. As stated once you verify, adequate power to the coil and switching of the ground by dizzy, you have made an accurate diagnosis, which leads to a proper repair.
Plugging in many parts is like clearing heavy traffic with your cars horn ......... leads to rage.

["QUICK-SILVER"]

Originally Posted by 64speed

If you havent read my previous post on intermittent surging please do so. Well after replacing the WHOLE fuel system the surge was still present on the test drive and I made it back to my house where it died in the driveway. Now it turns over and will not start no matter what I do. So I guess the only thing left to do is replace all the ignition components? Whats the average life of a pertronix unit? Could it have been slowly failing this whole time? Thoughts?

Originally you found that pouring gas in the carburetor it would fire back up.
So I would have to say no about the pertronix failing this whole time.

You may/maybe not have another problem now. You've got to check and see if it's fuel or spark this time.

Definitely curious to see what you find. Got my fingers crossed that it's not the fuel pump eccentric or timing chain.

[64speed]

no the rotor is turning when the switch turns the motor over so the timing chain is not broken.

[Greg Reid]

Originally Posted by 64speed

If you havent read my previous post on intermittent surging please do so. Well after replacing the WHOLE fuel system the surge was still present on the test drive..

Did you verify that fuel is actually being delivered? As I recalled in my previous post, I had a similar problem that turned out to be the fuel pump eccentric. This was after replacing or checking everything including the pump. When it finally died completely and would not start (like yours is now) I pulled the line at the carb and turned the starter over- No fuel out of the brand new pump. I removed the pump and gave it a couple of shots by hand and fuel shot out.
I then knew that it had to be the eccentric.