*HELP* Starting issues!

[68suprB]

68 super bee 4 spd
383 bored .30 0ver
Pertronix Electronic Conversion
Comp Cam 292 duration .501 lift
Stock rebuilt Carter 4bbl AVS
New fuel line from tank to carb
If the car sits 1+ days or so, gas pedal has to be pumped 10-15 times, then motor will fire up, run for 2 minutes or so at idle and stall, then secondaries must be held open manually while cranking to get it to start again.
Today I pulled the carb off and completely tore it down, cleaned and re-assembled it (all gaskets ok). Car started up with a little hesitation, idled for 15 minutes then i drove it 10 miles with absolutely no issues, didn't stumble, stall, etc...good power and ran perfectly fine. After parking it I let it sit 20 mins....nothing. Starter is engaging, but motor will not start no matter what, even tried starting fluid with no luck. Here's what I'm thinking:
1) Somehow the carb is the issue
2) I could see air bubbles coming into the fuel filter from underneath (filter is directly under fuel pump) and the fuel gradually drains back out of the filter the longer it sits. I would think this would be an issue after sitting for several days because it would be sucking only air in for a few seconds until the pump can pull the fuel back up to the carb, but not after running for 20 mins and only sitting for 5 minutes
3)along the same lines- maybe a pinhole in the gas tank somewhere? Fuel line is totally new from the gas tank to the carb, but if the air is being introduced before the fuel pump, it must be the gas tank?
Thanks guys

 

[HEMI-ITIS]

Even if the fuel is bleeding back,there should be enough fuel the the bowels to start and run while the fuel pump bring fuel back up the fuel inlet.:blob1:

 

[snakeoil24]

Are you getting spark?

 

[440roadrunner]

Fuel boiling off seems to be a "modern problem" with ethanol fuels.

I would definitely confirm that your spark is OK

To do this you MUST use the key unless you are running a system (like MSD) with the ballast bypassed.

Rig a spark gap at the coil tower and crank the engine using the key, you should get a nice hot spark at least 3/8" long or longer

Next time you suspect the problem will occur, before you do ANYTHING else, remove the air filter, use a flashlight if necessary, and see if a pump from the throttle gives you anything from the accelerator pump. This will confirm that fuel is boiling out of the carb

On my 67, the things I did to reduce vapor lock/ fuel boiling problems are:

installed a vapor return system, easy with the proper Wix filter, 33040/ 41 which have built in return ports

Installed an insulator gasket under the carb

I finally eliminated the mechanical pump, and mounted an electric back at the tank.

Turn on the key, let the pump run for a couple of seconds. Even last winter, we had some nice sunny 25F days, and about 4 pumps and she's runnin!!!!

 

[68suprB]

Just pulled a plug and checked, no spark...but how could it go from running fine, parking it and turning it off, then there's no spark 5 mins later? just don't make sense....

 

[ArtH]

Check the air gap on the pertronix module and rotor; the kit should have come with a plastic (non magnetic) gauge for this purpose. Off hand, I can't think of what the gap should be but you could look that up on their website - I think they have pdf file instructions you can download.

The second thing to check is if it is working at all. The old Pertronix units will burn out (for lack of a better term) if the key is left in the ON position and the engine not running. Supposedly, Pertronix II solved that problem.

Make sure you have the correct coil. When I converted (two cars) I bought the Flame Thrower coil they recommend. Again, I forget the value in terms of Ohms, but there is a difference. Also, Pertronix wants battery voltage so you should not have any resistance going to the positive side of the coil. I have run my engine by jumping from the positive side of the battery to the coil with pertronix unit in place. The engine will run with the key off. I currently use a relay that sends battery voltage to the positive side of the coil when the engine is started. I've had a Petronix I unit on my 72 Lincoln for years with no problems. I also converted my 77 Cordoba using their distributor and it too runs fine.

Check your voltage reading at the positive side of the coil to make sure you are getting 12 + volts there. If that's okay, just check the wires from the pertronix module to both sides of the coil. Make sure there are no shorts or breaks in the wires. It shouldn't take you long to do that. If you can establish they are in good order, then I'd suspect the coil has failed or has an intermittent failure going on. Either way, you would need a coil.

 

[ArtH]

With regards to your fuel line. Check the flexible connection (usually rubber fuel line) from the tank to the steel line that runs to your fuel pump. Years ago, I had a car giving me fits trying to start it. When I saw that 12 inch pos hose, I could see it was sweating. I replaced it and found that with my finger plugging one end and applying vacuum to the other end, it would not hold vacuum. It was shot.

 

[68suprB]

Thanks art, I'll take a look at the flexible fuel line but it's new so shouldn't be the issue. I looked at the voltage regulator today, and it looked fried. The bottom coil was black and even the backing looked burned up, so I replaced it, but still nothing. I tried switching coils and still nothing, so i think my problem may be the pertronix unit. I did accidentally leave the key in the "on" position the other day for an hour or two, and I'm thinking i fried the pertronix unit, even though it is supposed to shut off after an extended period of time. There is power all the way up to the coil but not afterward. Maybe changing to a new one will help....