Quit Running

My guesses - manifold/vacuum hose leak or bad fuel bowl level or float? I'd check those first

You have a fuel supply problem.
Unless you like to donate $120 everytime out you should go through the system.

Start at the carb. Before you pull it off, check the fuel level. If it seems about right, go to step 2, check the fuel presure.

I personally would check it with the tank low, close to empty.

If that is ok you need to check for debris in the line and likely in the tank.

Take heart. The tank is "fairly easy" to drain and doesn't necessarily need to be removed. If you get to this point, then definately drain the tank from the factory drain plug. Anything could come out of there. You aren't missing your dog or cat are you?

Goodluck.

Richard,

I've seen ignition modules and the pick up in the distributor both make a car behave that way when they are failing, the motor dies, then works okay for a while, then dies again. In other words, they don't die completely, they fail intermittently, more often than not heat related (the motor will restart when the ignition cools off).

An egr valve that sticks open will also kill a motor at idle, but they don't cause backfiring. I'm asuming you don't have an egr system since you have a Holley carby.

Engines backfire when the exhaust system collects unburned fuel, because the ignition isn't igniting all the cylinders, or because the fuel system is running very rich. So the fact your engine was backfiring before it died tells me to suspect those two things.

A dirty fuel filter will allow a car to start & idle just fine, but will make the motor lurch under load like going up a hill, due to a lean condition, not a fuel rich condition. Carburetor floats that sink or are saturated make the car run rich and make it hard to keep it idling. But once saturated, carburetor floats don't work OK again. When they are dead, they are dead. Same thing goes for crud stuck in the fuel bowl needle, once it is stuck open, they stay stuck open.

That is why my first impression, based on the info you've provided, I lean towards suspecting the ignition. Intermittent problems are normally electrical.

Get yourself an aerosol can of that electronic "freeze" stuff. When the motor dies again, spray the ignition module to cool it off and see if that brings the motor back to life. Or just install a new module, and drive the car. If that's a Mallory Unilite dizzy, well, I've written warnings here before. The Unilite will cause problems from time to time.

There is also the possibility the voltage supplying your ignition system is on the borderline of being too low, due to high resistance in the ignition switch.

good luck my friend

cowboy from hell

quote:

If that's a Mallory Unilite dizzy, well, I've written warnings here before. The Unilite will cause problems from time to time.

2511 had a Unilite when I bought it.

26,000 miles later I've had the following problems with it -

zip, zero, nada, nothing

I have talked with folks that had problems with their Pertronix conversions, and read of many owners that have repeatedly sent in their MSD boxes for rebuilding.

Any electronic aftermarket device is subject to failure, just as an OEM part.

George for some reason dislikes them, but my Unilite just keeps on tickin.

YMMV

Larry

LOL...

Larry, I'm equal opportunity! I don't like the MSD 6AL either!

The most reliable ignition really is the Ford Duraspark, although I'm not a fan of Ford distributors.

The Mallory Unilite is a lot like me, its been around a long time, and I've seen them fail more than once or twice. Its not a matter of "dislike", its a matter of experience, the Unilites die a lot more often than the factory ignitions.

Not all Clevelands drop their valves either, but I happen to know a cautious gentleman in Fresno who recently updated his valve train!

quote:

Originally posted by LF - TP 2511:
...my Unilite just keeps on tickin...

Besides things that "tick" are possibly time bombs!

Love ya bro!

Just to add fuel to a lack of fire. I recently had an Accell Coil fail. It had to be hot and then it wold start producing an intermittent spark. I saw this with one of those tester pugs. Checking the internal resistance, it was a little off.

Thanks for all the help, Mark from Jersey even called me with his experiences. Before I head out to Kingston (300+ miles) I think I will flush the gas tank and change the module. It's a lot cheaper than being towed home.
Richard T.

When I used to run Mallory ign I took spares of everything(module,coil,roll pin etc)with me when I went on long trips.
I had a coil that acted like what you describe.
It was a promaster and it would start and run fine then after some heat it would miss and act up just like George described. At first I thought I had a roll pin problem(that came later but thats another story)because of the backfire. I changed the coil and it was fine until I took that ignition off of the car.
Good luck on your trip.

Just to start off I know why I never owned a Chevrolet. Id like to bump this and describe my issues. I started 1717 last Saturday, sounded differant than normal kinda like a "stuffed" muffler, went a 1/2 mile from the house and it just shut off. She tried to start but would back fire through the carb and never ran right again.
I have a Unilite with a Promaster coil.
My dizzy has been setup with dual pick ups. I pulled the one in use and moved the other to the correct side so I didnt have to rewire the cap.
I replaced the ballest resistor with a new Mallory #700 resistor. Also replaced the coil with a new unit.
Tried starting the car tonight and she did fire but would not run right. I shut her off.
Now where is this roll pin I have seen talked about here? Does the dizzy have to be pulled to replace this pin? Just a note fuel delivery is not a issue. Fuel is right on the mark in the bowls, and can see it discharge into the carb.
Help!!!!
I was just on the Mallory website, well so the roll pin is for the gear, I found a question in Mallory's knowledge base posted to them from a Pantera owner. Great answer from Mallory increase pin size to 3/16ths on Ford V8's.
Unilite Rollpin.

JeffS,

Just a note:

Before you remove your distributor, take the cap off and mark on the dist body where the rotor lines up to. Make another mark at the base of the dist and the engine block. Make sure the the bottom mark starts on the dist and continues right onto the block.

If your roll pin is intact, and the shaft did not spin, then the top mark will insure that you line the rotor back up with the cam and the engine will stay timed. The bottom mark will insure that your actual timing setting will remain the same.

If your roll pin did shear and the shaft did spin, the the bottom mark will still hold your timing setting, but you'll have to get your #1 piston back up to top-dead-center on the compression stroke (both valves closed), and drop the dist back in lining up the rotor with the #1 spark plug terminal on the cap. (You can start your timing with the bottom mark, but I'd chuck a light on it just to verify and/or adjust the timing.)

At this point if you were to mark the exact position of the rotor as it lines up to the #1 cylinder on the dist body (erase the old mark), you could tell if the roll pin had sheared again just by bringing the #1 piston up to top-dead-center on the compression stroke. If the marks don't line up, or are significantly off, you know that the pin sheared. Just keep in mind if you've adjusted the timing after making the mark to compensate for that amount of twist, or make a new mark.

Michael

Thanks Michael, Thats exactly how I was going to mark the dang thing, the tip on checking the number one position before pulling the distributor I havent thought of. Thats the first thing I will do when I get on it this evening.
Jeff

Thanks for the input guys, put number 1 cylinder up on the compression stroke. The rotor was off line by a "good" amount. So out came the bulkhead, I set the rotor to the number one position and the balancer was over 30 degrees off, so I put the balancer at the "0" mark, marked the dizzy and pulled it. Yep the pin was hanging out on one side. Pulled the rest of the pin, drilled out for a 3/16ths pin and reinstalled. Had to roll the crank just a little to get the oil pump driveshaft to engage the dizzy. Set the marks I applied, tried cranking and she fired up on the first try!
Shut her down cause Im going to change the oil tomorrow just in case any debris made it into the oil pan.
Again thanks guys. George I now consider the Unilite a POS. I know you like the Duraspark, what distributor do you use??
Jeff

Glad to hear you got it solved.

My dist pin sheared on my '74 when I was about an hour away from home. Once I determined that it was a timing issue, I kept turning the dist until the car started and ran. As I was limping home, it shut down again, so I twisted it as far as it would go and it barely ran, but I got home. I never tighten the bejesus my dist clamp bolt for this reason. I snug it so that it won't move, but if I put enough force to it, it'll slowly turn.

Michael