Tony2Shae

The title says it all. I am new to the forum and to the power Wagon clan, left the Chevy Square Body group for something much better, at least I hope. So here's the issue, I own a 78 Power Wagon. It's a 318 LA with a factory style Carter 2 barrel. It is a manual with the full time 4x4 setup. This thing WILL NOT stay running to save my life I swear. It has some wierd underlying problem and I'm stumped. Here's what's been done.
- Carb been Professionally Rebuilt
-New Fuel Pump and Filters
- New Gas
- New Coil, Plugs and Wires
- New Ballast Resistor
- New Control Module
- New Cap and Rotor
- Alternator and Battery have both been to the local part store and have passed their test.
- ignition has also been hot wired to eliminate the column.
Now that has all been done to get it to run, you can turn the key it will start up every time and it can idle in the driveway for up to a hour no problem. It will not make it around the block without shutting off. It doesn't stumble like vapor locking or lack of fuel. It just turns off. I am stumped. The timing has been checked and set for our altitude and still it does this. Please does anyone have any idea of what is going on.

RacerHog

Welcome to the site. Sound like it's got a vacuum leak. Check the hoses, intake, power booster, for leaks.

fivepoint

When you are driving and it does shut off, what do you have to do to get it running again? When it does shut off, have you looked in the carb and pumped the accelerator to see if the carb has fuel in it? When it shuts off, do you have power at the coil? I'm just trying to determine if it is a fuel or ignition problem.

Tony2Shae

Thanks Racerhog and Fivepoints. See that's just the thing, everything short of wiring has been replaced ignition and fuel. I have 2 Carter two barrels for the 318. Both are rebuilt and we have tired both on the truck. It has a new mechanical fuel pump and 2 new glass filters. One before the pump and one after. As to start it. Just turn the key and she will crank. I believe there was one instance when we let it idle for 45ish minutes and then very gingerly drove it maybe 200 feet and it shut off and would not start till the next day. But that is what I was told from my father in law he has the truck at his house in a different town. An as for Racerhog point, we have tried to see if there was a vacuum leak if any and we can't trace anything down from the tank to the carb. I checked 3 times and my father in law twice.

RacerHog

Ok... In that case it looks and sounds like all is good on those parts. And will assume No vacuum leaks exist. And providing all that is in great working order. I would say that we are back to the carburetor.
Most of those had a de-cell pod on the side of the carb. Some where spring operated and some where vacuum operated via the air amplifier.
( NOTE: These are not to be mixed up with the A/C Step Solenoid.)
The purpose of this service was to keep the throttle plate from slamming shut and causing the stall issue you are referring to (I Believe).

Tony2Shae

Thanks for the info Racerhog, I'mma give this another shot with the second carburetor I have. I'mma do it this weekend. Only thing that sucks with my line of work is having a project and working 6 days a week and being clocked in for 10-14 hours a day.

Gorts 5th

I had a buddy years ago that had the same issue.
it turned out that a paper clip had been used to make a test lead for the coil was left on and it would spin and ground out the coil causing the stall /not run.

dodgem880

While it's running wiggle all your connections and wires on the primary side of your ignition. Like at the ballast resistor, ignition module, coil terminals and firewall bulk head connectors. See if you can get it to stumble or die. I once had a bad connection at my ignition module plug that would cause the engine to die when idling for long periods. If I wiggled the bad wire on the connector the engine would stumble or die.

Use a voltmeter to confirm your charging system isn't over charging. I once had a bad voltage regulator that would overheat the ICM causing the engine to shutdown and not restart for hours.

You hot wired the ignition? So your connected your hot wire directory to the coil? (bypassing the ballast resistor).

If not, there are two wires for powering the ignition. One is pink for full voltage during cranking and one is red for ballast voltage while running.

The engine is not likely to start if hardwired to the ballast side, not enough juice..

Tony2Shae

Sorry I haven't been on in a while everyone. So I'm at a loss. Every component, voltage regulator, ballast resistor, fuses, carb, fuel pump, coil, cap and rotor, plugs and wires, got wired passed the key to eliminate the problem. An same thing. Truck made it to the same spot and shuts off.. battery has been tested and Alternator. Both pass. Tank Has been dropped and chemically cleaned.. new lines... Timing is set for elevation. 5000 plus feet.

Drag Pak

Any chance the distributor shaft is tight in it's bushings and overheating the magnetic pickup causing failure of the pickup?

RacerHog

Thats a good one. I had a bad reluctor in the dist. and it caused us to replace a few controllers.
You have made sure the controller has a good ground... Rite?

Tony2Shae

GREAT NEWS!!! I finally got the issue narrowed down... Kind of. I absolutely suck with electrical. However, I hooked a voltage gauge to the truck other than the stock one. When the truck shuts off it over charges the battery. When it starts it's just below 13 volts and when it runs it's at 13.8 so that's awesome. However when you start to drive and shift it begins to over charge the battery. It will instantly peg the charge to 18 or more. Gauge stops at 18. And the truck shuts off. And then it drops back to 13.8 Soo, with that in mind and all the parts changed. What could possibly cause this lol.

RacerHog

Answer on other post...