Posted by daniel on Wednesday, February 08, 2006 at 11:52PM :
In Reply to: truck is running funny not ha ha though. posted by Axle Steve on Wednesday, February 08, 2006 at 7:56PM :
If you think it's the switch: Take a truck lightbulb in it's socket. Wrap a wire round the body to make the other lead. put one end on the 'IGN' post on the back of the switch and ground the other on the body or the big center post on the switch which should be ground. Turn the switch to the run position and the light should be constant even with key wiggles.
If you suspect weak spark: Pull the wire to the distributor while cranking (use a big dry rag) and look at the spark. It should be white-blue, not orange. If Orange, your coil is probably weak.
If the idle circuit is whacked, the truck would still run if you pumped the gas before it dies. It would be obvious, as you stomped the gas while it was dying, that your pedal action kept it running. For a plugged line or shot pump, disconnect between the pump an the engine, aim the line in a empty can and crank it (Ground the big wire from ign. coil to distributor). Should be a good flow .
Next, reconnect both and peer down the carb throat while truck's off. Work the linkage and look for a stream of gas from the accelerator pump spigot, down the barrel.If none,do what Dave S. says.
As far as the plugs, you could break off the contact and the thing should still run, so gap is a smaller issue.
Check that the frame, engine and body are grounded. Ground wires, funnily enough, get left off quite a bit o the time.
Daniel