Ad Radar
Facebook Click here to find out more!

383 Runs Rough, Will not stay cranked

Mopar Muscle
Item Posts    Sort Order

383 Runs Rough, Will not stay cranked

bama_d bama_d
New User | Posts: 2 | Joined: 10/13
Posted: 10/14/13
06:11 AM

I have a 68 Dodge Monaco.  It was my dad's car I got in 2005 when he died.  He was a very good shadetree mechancic and rebuilt the engine in 1995, drove it a little, and then let it set for years.  I got the car and restored it - new paint job, repaired gas tank, etc., everything needed to get it running again.  It's ran good for 7 years now.  I had driven the car in February and it ran as usual, no problems.  Next time I tried to drive was in June - I know, I shouldn't let it set that long and that's the first time that's happened.  In June, when I cranked, it ran rough, missing, wouldn't idle.  Finally died after ~10-12 seconds and wouldn't crank at all after that.  Note - when it's set for a while, I always just poured a little gas in the carb, and it would fire right up and run okay after a few seconds.  But this time, it was a very rough idle, missing, died. So I'm thinking ignition.  It still had the points/condenser setup, so I finally broke down and replaced this weekend with the electronic ignition module and new coil.  Poured a little gas in the carb, and it cranked, but same thing - running like crap.  I could keep it running, even though rough, but I was by myself and couldn't get to the front and keep it going to check anything.  So when I let off the gas, it died.  Never could get it to crank again.  I know the problem is not in the firing order because absolutely nothing had been done since it ran okay in February.  I did not replace the distributor cap because again, it was okay in February.  So not sure of the problem.  Maybe fuel issue?  I did change a fuel filter I had put in right before the fuel pump.  It looked bad - sort of gummed up.  That didn't help, still wouldn't start.  I started thinking old gas, but that doesn't make sense because I'm pouring new/good gas in carb to start - it should at least fire.  Voltage regular?  Could carb be gummed up causing this?  Carb is new 4-barrel Edelbrock installed in 2006.  I'm not sure where to go right now with it and asking for help/suggestions.  Thanks  

waynep712222 waynep712222
User | Posts: 127 | Joined: 04/13
Posted: 10/14/13
08:07 AM

gasoline can go bad in a few weeks... or if the cap does not seal.. much faster than that..

more to come...

you probably have fouled the spark plugs...

which ignition did you install????

did a resistor bypass get installed so there is additional voltage to the positive side of the coil while cranking???

got pictures..

can you clip a test light clip to the positive side of the coil... shove the probe into something to ground it...

turn the key to the RUN position.. you should get a medium bright test light..

while cranking.. you should get a bright test light..

returning the key to the run position.. you should get a medium bright bulb again..  

bama_d bama_d
New User | Posts: 2 | Joined: 10/13
Posted: 10/15/13
07:55 AM

Cap on tank was sealed- I checked and it was tight.

Could be fouled plugs but wouldn't even a fouled plug(s) still fire somewhat after the car ran bad after initially cranking.  There was no fire at all after the initial crank - both June and past Sunday. You would think it would at least try and crank again, and run bad again.  Wouldn't even do that.

I did jumper across the ballast resistor with a wire.  I didn't remove the resistor, just put a wire between the plugs - I think that should do it.

Electronic ignition I installed was an Accel POINTS ELIMINATOR CONVERSION PART NO. 2030.  The coil was an Accel 8140 Cannister coil.  Instructions say can use without ballast resistor if using this coil - that's why jumpered across the plugs.

Some more info - talking with a friend who has always messed with older cars.  Subject of battery came up.  Both times car cranked and ran bad, I had just charged battery.  Both times car cranked on first try.  Subsequent to first crank after going dead, you could easily hear battery going down fast trying to re-crank.  You couldn't crank the car more than 10-12 seconds or so without getting close to zero.  I would put the charger back on the battery while I was checking other things and re-cranking.  Battery never did go back to full after first crank.  Can the battery have insufficient voltage to maintain good spark/fire, but have to enough to engage starter?  Battery is 7 years old.  To eliminate this altogether, I went out last night a bought a new battery from Advance Auto - they had a coupon for $40 off purchase over $100.  So the car gets a new battery and eliminates low voltage/bad battery as a potential problem, even if it wasn't one.

My friend also mentioned a test light, which you advise as well.  I'm going to swing by parts place and get one next day or so.


waynep712222 waynep712222
User | Posts: 127 | Joined: 04/13
Posted: 10/15/13
12:12 PM

HF 30779 Zpsc0772e7e
this is a harbor freight 30779  and is under 5 bucks..


this is a harbor freight 37772 and is 20 bucks..

this is a coil output tester .. available at most parts stores for under 8 bucks..


you can even make your own...


or just position the end of the coil wire 1/2" away from the engine block..

please.. DON'T hold the coil wire with your hand.. while this is being done..

it may turn into a shocking experience..

it takes a minimum of diagnostic tools to work on cars...

a digital volt meter.. since you don't have points.. you can get by with a conventional volt meter as is shown above..

a test light..

a spark tester...

a timing light, a vacuum gauge, are also part of a minimum diagnostic tool kit..

a remote starter button also helps a LOT...

i expect that you have a spark plug socket and enough hand tools to change them.. and on mopars that can be a challenge.. i used to do the spark plugs on my aunts 68 new yorker.. from under the car.. it was quicker..  but that was a 440..