No start issue on my 1979 Magnum

[Pete Kaczmarski]

I know its should be on B Body forum but I suspect most of them don't have lean burn system.

Yesterday I had taken my '79 Magnum GT out to get to my '62 Chrysler 300. It started normal and I parked it outside. A couple of hours later I tried to start it and it cranked normally but did not seem to "pop". I gave it some gas but same result. I have a tool that tests if it has spark and how much attached to a spark plug wire. Several times is said "excellent". I held the gas pedal down to the floor and other methods including starting fluid, same results. You could smell the gas so I took all plugs out (some could smell of gas) and replace with new ones. Still nothing. One thing was weird was several times when I stopped cranking it it sounded like when a car "diesels" on shutting it down. It did that several times for about one second each. That made me thing of timing. A friend stopped 30 minutes later, reached thru the open window and it started immediately. Any thoughts? I suspect a faulty "Lean Burn Computer".

 

[Davea Lux]

I know its should be on B Body forum but I suspect most of them don't have lean burn system.

Yesterday I had taken my '79 Magnum GT out to get to my '62 Chrysler 300. It started normal and I parked it outside. A couple of hours later I tried to start it and it cranked normally but did not seem to "pop". I gave it some gas but same result. I have a tool that tests if it has spark and how much attached to a spark plug wire. Several times is said "excellent". I held the gas pedal down to the floor and other methods including starting fluid, same results. You could smell the gas so I took all plugs out (some could smell of gas) and replace with new ones. Still nothing. One thing was weird was several times when I stopped cranking it it sounded like when a car "diesels" on shutting it down. It did that several times for about one second each. That made me thing of timing. A friend stopped 30 minutes later, reached thru the open window and it started immediately. Any thoughts? I suspect a faulty "Lean Burn Computer".

Sounds like you are not getting power on the start circuit to the ignition. Check the connections to the ballast resistor to sure you are getting power in and out of the resistor. Yours should be the dual path type and the start path may have failed or the terminals are corroded from sitting. If you have the car parked any where near a transformer or under high tension wires, that can cause issues with the lean burn computer because it is not shielded for magnetic interference.

Dave

 

[Pete Kaczmarski]

Thanks for your thoughts. The car is super clean so I suspect no corrosion by the ballast resistor but will double check. In my experience when the ballast resistor goes bad it will run in the crank position but when key is released to run position it stops running. As far as power lines the car was about 60 feet from them plus a building for that distance. For the fun of it I tried a 360 2 bbl computer today and it did start right up like normal although not the one for a 360 4bbl.

 

[traintech55]

Sounds like the pickup coil inside the distributor is bad. If you can lay your hands on ANY Chrysler electronic distributor, plug the orange and black connector into the harness, turn the key on, and spin the test distributor by hand, look to see if you have spark.

 

[Mopars & Missiles]

Typical lean burn problems, sounds like yours has changed the timing too much. My 79 Magnum would periodically do stuff like that. Once on a long highway trip (family vacation), stopped at a red light (was doing about 60 prior) and the thing immediately started loading up. Bunch of black smoke out the exhaust for what seemed like several minutes. Was all I could do to keep it running. It did finally die right there in the middle of the highway at the light. Fortunately, I was able to get it to restart before to many irate drivers gave me the horn. Nursed it off the highway and into a parking lot where I could try to check out the problem. Couldn't find anything wrong for sure but did several checks on the computer connectors (for corrosion, poor mate, etc. looking for a needle in the haystack). Anyway, after it cooled down for awhile it fired back up and ran normally for the rest of that trip. (Mine was 360-2) Ended up replacing that computer later on anyway. Lean Burn systems were an advance for "their time", but realistically they were pretty primitive and unreliable. I think a large part of the lean burn computer problems are "heat" related. I admire you for still running a stock lean burn in your car. Good luck.

 

[65sporty]

Are you really attached to the lean burn system? I would ditch it and convert it over to a Mopar electronic system like this one.

 

[furious70]

The ignition switch could be the culprit too