Missing bad out on road.

drscott

drscott

Member
30 PU is missing really bad when running on road. Idles good but won't hardly run while out on road. I've had a great model A gentleman help me all winter on this truck. I will get his thoughts next week. It acts like it is starving for gas. Got it home took off gas line, very little debris in bulb. But gas did not flow through line very good.

Any thoughts would be greatly appreciated.
 
First you gotta' find why WHY the gas is not flowing well! With gas line off at carb, Minerva would flow a 5 to 6" stream, with only 1/2 tank of gas!
It's just a simple process of elimination.---Bill W.
 
Forget that "point setting" stuff for now. Like Bill W. said above, find out why the fuel is not flowing. With that line disconnected, blow some compressed air BACKWARDS thru that line to possibly dislodge some crud at line/tank. If it flows better, you've found problem. Use all these little clues to your advantage. DD
 
Took off gas line. Took off bulb no dirt in bottom. Put bulb back on and it took about 1 to 2 seconds to fill up. Getting ready for test drive again.

Points are ok.
 
Is the miss just one miss every now and then or does it start missing and it feels like it is ready to die off completely?
 
Same thing. Missing real bad as soon as it get a load on it. Did a quick check of the timing. Seems to be ok. Again, starts right up and idles perfect.
 
Take fuel line out of carburetor and watch the flow. As Bill said, it should flow fully and not stop or slow down.
The line into the carburetor should extend beyond the ferrule by more then a 1/16" or so.
Make sure the gas cap vent is doing its job. When this monster starts running poorly just loosen the gas cap and see if that helps.
Does this monster run OK at lower speeds and just start running poorly at higher speeds ?
If this doesn't help, maybe the carburetor will have to come apart.
I'd work on the fuel system before fooling around with some electrons.
 
It takes higher voltage to fire the plugs under load than when idling. Hold the coil wire 1/4" to 1/2" from a head nut and check for a hot blue spark. My original slant pole coil will easily throw a 1/2" blue spark.
 
Point gap
Point gap
Point gap

Classic symptoms.

Been there. The point gap is too small. Symptoms makes you think it is fuel.
(Less likely but it could also be a bad condenser.)
 
Point gap an easy check do that and then make sure that the ferrule on the gas line into your carb is not set too far back from the end of the line......if it is and your fuel line is 'into' the carb too far then you will have a gas starvation problem it is blocking the fuel flow.

Happened to me years ago.
 
I agree with V8COOPMAN. If your stream is very weak,,,,i am talking about your fuel stream,,,Then maybe small debris or rust blocking your tank drain at fuel line.
 
As in post #7 pull the fuel line off at the carb and blow some compressed air back up into the tank to clear things out. Make sure your fuel system is right before you start on the electrical side of things.
 
you can also run a piece of wire thru the line if its old it could have a lot of crud in it . if it starts to "starve for fuel what happens if you pull the choke rod when it happens?
 
This may sound crazy, but check the spring tension on your points. I had the springy part of my points break once. The thin copper conductor had just enough springiness to close the points at idle. Once I was moving at speed, however, the points would float like crazy and you can imagine how lousy it ran.

It took me a long time to find the problem. The points looked normal when I was troubleshooting. I didn't notice until I manually pulled the points open and notice how there was so little tension. Then I noticed the little piece of broken spring.

Good luck!

Ken
 
Where the fuel makes a 90* turn in the shut off valve very fine sediment get packed in. Pull the fuel line off at the carb, hook a hose on, and drain the fuel into gas cans. If the fuel valve is packed may take hours. Then remove the fuel valve clean the gunk out install a pencil filter and motor happy.
 
KGBnut said:
This may sound crazy, but check the spring tension on your points. I had the springy part of my points break once. The thin copper conductor had just enough springiness to close the points at idle. Once I was moving at speed, however, the points would float like crazy and you can imagine how lousy it ran.

It took me a long time to find the problem. The points looked normal when I was troubleshooting. I didn't notice until I manually pulled the points open and notice how there was so little tension. Then I noticed the little piece of broken spring.

Good luck!

Ken
Click to expand...

That was my thought as well.
 
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