Dave Hall wrote:
On 19 Dec 2004 19:24:09 -0800, wrote:
I have an early 1980's modle 318 Chrysler engine installed in a
mudboat. About 2 years ago I developed a problem with the Ignition
coil burning up. The engine has the original electronic ignition
system installed, but has been completely rewired by a Dodge
dealership, the control module, ballast resistor, and the
distributor
pick-up assy. have been replaced. However, I continue to have the
problem. The engine runs perfectly for about 3 months and then
without
any warning, will backfire and die. There will be no ignition fire
until the coil is replace, then the engine will start up and run
fine
for another few months. Any help or suggestions with this problem
would
be GREATLY appreciated.
Sounds to me like your coil is being "fried" because there is too
much
voltage being run through it. Most coils are designed to run at the
full 12V when starting, but then switch in a dropping resistor which
drops the voltage down to about 8V when running. If this dropping
resistor is absent, the coil will get the full charge at all times.
Another thing to check is your charging voltage. If your alternator
regulator is acting up, and the charge voltage runs up to 16 or 17 V
the same thing could happen. Although, you'd probably notice your
batteries boiling over and very bright lights as well.
Dave
I appreciate all the responses very much. The resistor resistance is
app. 1.2 ohms and running voltage is 8.2 volts. Alternator output is
14.4 volts. The coil is mounted directly to the block and the bracket
seems to be tight and clean, no signs of corrision. I tried install a
higher resistance resistor and dropped the running voltage to 7 volts,
but that made the ign. fire too weak. I have tried using Mopar coils
as well as aftermarket coils with no noticeable differance. Someone
suggested using a HEAVY DUTY coil, where can I buy one and what do I
ask for? This problem certainly has myself, the Dodge dealership and
several local independent mechanics scratching our heads.
Thanks again
Ronnie