340 ignition problem?

OK, very first thing is to try and split the problem as to whether it's "fuel" or "electrical."

Some things you should just HAVE, period end of story

You should have a multimeter of some sort. Even a cheapie Horrid Freight "if it works right" is better than nothing. You can pick up a decent meter at any parts store, or Sears or even Radi Shack for less than 50 bucks

Go to Radio Shack and get a bag of clip leads

Get a shop manual and by that I mean a CHRYSLER shop manual, not a Haynes, not Chiltons, or some other. You can buy reprint paper ones, or "on CD" Google around

You can download several shop manuals on this site, but unfortunately none of them are newer than 72, and in either 73 or 74, there were considerable changes in the wiring, so using a "wrong year" diagram can get you into trouble.

So pick up a multimeter and an auto store "spark tester." There are various kinds.

Make some tests:

Set your meter to low DC volts, and clip one lead to the coil plus terminal, the other to battery, such as the starter relay big battery stud. Remove the coil wire and wedge it against something to ground it, so the engine will not start

Prop the meter up so you can see under the hood gap, and crank the engine USING THE KEY. While the engine is cranking, read the meter. You are hoping here, for a very low reading, not over .3V (three tenths of one volt) or .4V at the very most.

Now clip the meter to the same battery source, and the "key" side of the ballast. If you have a 4 terminal ballast, this is the end of the ballast with a jumper across the two end terminals.

With engine not running, turn the key to run, and read the meter. Once again, not more than .3V is acceptable.

If this checks out, some "general" stuff.............

Remove the cap and check the rotor for debri, damage, dirt, moisture, or wear

Look over the reluctor and pickup coil for strike damage, rust, or debri. Get a .008" brass feeler gauge (inches not metric) and O'Reallys Auto had these last I looked. This is the gap you want to set the reluctor to pickup coil gap

Wiggle the dist. shaft while looking at this gap and check for side - to - side bushing wear.

Use your multimeter to check each plug wire AND the coil wire. If these are older resistor wires, you want no more than 1000 ohms per foot of wire. Most are less.

Use your spark tester to check spark. Ground the tester, hook right to the coil, and crank USING THE KEY. You should get a nice hot blue spark, at least 3/8" long, and usually about 1/2" As the engine cranks, this should be a nice rythmic spark, bang bang bang..................

Remove and inspect the ignition box. Clean/ scrape the firewall and rear of the box clean, and re-mount using star lock washers. Make sure it's tight.

Remove the ignition box connector, the ballast resistor connectors, and the distributor connector. Inspect them visually for damage or corrosion, and work them in/ out several times to "scrub" the terminals clean, and "feel" for tightness.