Troubling ignition/running problem

Heres the lowdown..1980 F350 w/ 400m. Just bought a new Holley 600. At first the truck started and idled just fine. 2 days later it would die 30 seconds after idling. Now it does fire up immediatly but will not stay running..I was asked to keep the key turned forward and give it gas to see if stays running and it does (but only did that for a few seconds, didn't want to damage starter or flywheel) The ignition switch is new and adjusted, getting 12v at the new coil, getting gas at the carb and the fuel pump is pumping. I had the ignition module checked out and it is good. Distrubitor checks out. Timing has not changed. I even went as far to run a wire from the battery to the + of the coil just to check..same result,, Motor instantly fires but will not stay running. I'm at my wits end. Any help is appreciated.

Have you checked for a vacuum leak?

Have you checked for a vacuum leak?

yes no vacuum leaks..I guess the next step is to check for continuity with all the wires but may be in vain,,i have fire,,,have gas..it does fire up but don't stay running..
the search continues
ty

are you sure you are getting 12v at the coil when it dies. if so see if your floats are set right

are you sure you are getting 12v at the coil when it dies. if so see if your floats are set right

That was the old problem... read my post..this is brand new (in the post)....now the truck does fire up but won't stay running...gas aint the problem..btw,,floats are correct..fuel aint the problem...
something to do with the ignition..but don't know...someone had mentioned the voltage regulator...???..I doubt it but said that it's all tied in together somehow..

Check your secondaries and make sure the butterflies arent stuck open just a hair. If you gassed on it and made em open , they may not have seated all the way closed. Also, have you tried adjusting the idle air mixture? If not, run em in all the way, and back em out about 4 turns and adjust from there. The idle circuit may be too lean. You can check it by holding the choke closed partially and see if it stays runnin then, if it does, its in the idle circuit or you missed a vacum leak somewhere. You can also spray some carb cleaner in the carb when it tries to die and see if it picks back up.

EDIT: you might put a test light on the coil, and check a spark plug to see if youre losing fire when it goes dead.

does it spit and sputter or does it just cut out.

Check your secondaries and make sure the butterflies arent stuck open just a hair. If you gassed on it and made em open , they may not have seated all the way closed. Also, have you tried adjusting the idle air mixture? If not, run em in all the way, and back em out about 4 turns and adjust from there. The idle circuit may be too lean. You can check it by holding the choke closed partially and see if it stays runnin then, if it does, its in the idle circuit or you missed a vacum leak somewhere. You can also spray some carb cleaner in the carb when it tries to die and see if it picks back up.

EDIT: you might put a test light on the coil, and check a spark plug to see if youre losing fire when it goes dead.
The Carb is brand new (1 week old) and ran like a champ up until this problem.
The coil is getting 12 volts with the ignition on and while cranking. My f250 did sort of the same thing and I had to run a separate wire from a push button ignition switch because my column was all screwed up from a previous theft attempt. This problem is different..if I'm getting 12 volts at the coil I should be able to bump start it at the solenoid and have it start and run. It just fires but won't stay running unless I keep it bumped...and that aint good for the starter of flywheel. This problem is definitly electrical..

A friend suggested that I replace my tumbler and see if that helps but I dont see how it would.
But any all all suggestions are appreciated ty Uncle.

does it spit and sputter or does it just cut out.

The dang thing acts as if I cut the ignition off..picture this I hit the starter it immediately fires up but dies as soon as the tumbler returns to the ignition position. If I keep the key turned to start position i can give it gas and it will run (not good for the starter or flywheel if even for a few seconds)
The Carb is brand new and ran like a champ for 3 days until this electrical crap starting happening.
The ignition switch is new and adjusted, coil is new, and ignition module was tested.
sorry to answer ya question, no sputters or spits...just dies,

appreciate ya input bucketabolts.

ok, the reason i suggested the idle circuit, is because new carbs dont always come preset correctly, and could have similar symptoms. But if you hooked a jumper wire to the coil, and you arent getting spark except when you turn the key to start, it sounds like youre not getting voltage to the ignition module. Check for voltage at the red wire on the 2 wire connector. Look here for diagrams of your system:
http://autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0a/50/6e/0900823d800a506e.jsp#hd1-1-1
It could be a bad connection at the pigtail, or a bad wire in between there and the switch. You might double check the adjustment on the switch. When you look at the schematics, youll see whats going on when you turn the key. Scroll down till you find the ones for the module wiring, and left click on it to enlarge it in a seperate window.

Edit: check all your grounds also, body/frame/engine , bad grounds can cause some strange problems sometimes.

ok, the reason i suggested the idle circuit, is because new carbs dont always come preset correctly, and could have similar symptoms. But if you hooked a jumper wire to the coil, and you arent getting spark except when you turn the key to start, it sounds like youre not getting voltage to the ignition module. Check for voltage at the red wire on the 2 wire connector. Look here for diagrams of your system:
http://autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/0a/50/6e/0900823d800a506e.jsp#hd1-1-1
It could be a bad connection at the pigtail, or a bad wire in between there and the switch. You might double check the adjustment on the switch. When you look at the schematics, youll see whats going on when you turn the key. Scroll down till you find the ones for the module wiring, and left click on it to enlarge it in a seperate window.

Edit: check all your grounds also, body/frame/engine , bad grounds can cause some strange problems sometimes.

Uncle...I am getting 12 volts at the coil..even without the jumper,,and the module..I was asked to try that just to see. I had a f250 with a sort of problem..got 12 volts at the coil but nothing to the solenoid,,i just installed a push starter button..to the solenoid..truck was attempted stolen so the ignition was all screwed up...that worked.
,,I know some carbs aren't right from the factory but this one was dead on...ran great for 2-3 days..
Then one day is goes wonkers..I have noticed that the tumbler is kinda tight and has been since the days I had the truck..gonna buy a new tumbler ..just to check,,I need one any how..
thank fer the website to trouble shoot it,,that will come in handy,,
thanks again.

Take a 12v test light and check the coil negative if it is blinking you should have spark. If it doesn't blink the pickup in the distributor is bad. If it is blinking hold a spark plug to the block if getting fire. I would check the fuel pump and fuel filter. Otherwise a plugged air filter will shot you down.