Engine Died on 1st Ride Won't start

-

domdart

FABO Gold Member
FABO Gold Member
Joined
Feb 14, 2015
Messages
398
Reaction score
233
Location
Johnstown, PA
I'm almost done with my first restoration. I put a 72 340 into a 68 Dart. I broke in the engine about a month ago. I've been starting it and running it till it gets nice on hot every 2 or 3 days. I took it for a ride for the first time last night. I went a mile down the road and back. When I got back, the car stalled right in front of my garage. The starter cranks but the engine never tries to fire up. It is getting fuel. I pulled a plug to test for spark. My wife cranked the starter a few times. I only saw one spark and it seamed weak. I had my choke hooked up to my coil causing the terminal to glow. I've since hooked it up to the input side of the ballast. The engine always started as soon as it cranked. I have a multimeter (used it once to find the input side of the resistor). I'm going to put a new coil and resistor on it tonight. What kind of diagnostic tests should I do?
 
Electronic or points ignition?
And if it is electronic, did you remove the ballast resistor to get 12 volts to the coil?
 
I tried starting it every 30 minutes or so. It never tried to start. It is an electronic ignition from the 72 duster. I had the 72 distributor rebuilt. I have a new ignition module, a new voltage regulator, and a new v8 harness from Bill Evans. I used an old coil and the ballast from the 68 Dart. Oddly, when I pulled the plug and cranked it sounded like it tried to start.
 
Check your grounds. The motor should at least try to fire with a bad ballast resistor, it'd just die when the key was in the "run" position so I think your problem is elsewhere.

What's the voltage to the coil?
 
If your getting 12v at the coil I would try a different Ignition box.
 
MSD any other ignition is a waist of time. Mopar electronic systems are over 40 yrs old and were not that good in the 70's. Ignition systems have come a long way.

Do you still use a rottiery phone? Could you go online in the 70's? Rest my case.
 
It is an electronic ignition from the 72 duster. I had the 72 distributor rebuilt. I have a new ignition module, a new voltage regulator, and a new v8 harness from Bill Evans. I used an old coil and the ballast from the 68 Dart.

correct me if I'm wrong, but shouldn't you remove the ballast resistor in order to run an electronic ignition?
 
I only saw one spark and it seamed weak. I had my choke hooked up to my coil causing the terminal to glow. I've since hooked it up to the input side of the ballast. The engine always started as soon as it cranked. I have a multimeter (used it once to find the input side of the resistor). I'm going to put a new coil and resistor on it tonight. What kind of diagnostic tests should I do?

This can be a number of things, and there are some checks you can make. You may have "done something" related to the choke.

"What you need." (in general)

Get yourself a spark tester so you can look for spark without help. I use a Lisle, like this

s-l300.jpg


You already have a multimeter, and you need a 12V test light

Get a few alligator clip leads. Radio shack used to have. You can buy them through online electronics suppliers, Digikey, Mouser, some others, and on ebay

=========================================

First thing to do is determine if the system is getting power in BOTH start and run. These are two different circuits. "Clip" your meter to the coil + and to ground. Turn the key to run, note the reading, and then twist to start and note the reading while in start

You should have 5-8V or so "in run" and you should have "same as battery" in start. That is, if the battery sags to 11V while cranking, then you should have close to 11V at the coil + when cranking.

If not a quick check..........take an alligator lead and run power direct from the battery (starter relay) to the coil +. Do not leave this hooked up longer than necessary to test.

Make sure the ECU is GROUNDED. Dismount the box, clean the firewall and back of the box flanges, and remount tight, with star lock washers.

Work all connectors, the ECU, the ballast, and the distributor ESPECIALLY in and out to scrub them clean and to feel for tightness

Remove the distributor connector. Turn the key to "run." Repeatedly touch / untouch the bare side of the connector on the "engine side" of the distributor connector to ground. Each time should produce one spark snap.

DO NOT check spark (to start with) through the wires, as resistance wires can lead you astray. "Rig" your spark checker right at the top of the coil tower, to ground. You should get a nice fat spark, perhaps 3/8" long or more.

Rig your multimeter to the distributor connector. Set the meter to LOW AC volts and crank the engine. The distributor should generate about 1V AC.

Inspect the interior of the cap, rotor, distributor. Look for dirt, moisture, damage. Look for strike damage between the reluctor / pickup coil, and check the distributor for shaft wear. Buy a .008" (inches not metric) brass feeler gauge and check / adjust the reluctor to pickup gap.

================================

With the system connected "normal"

and assuming you have cranking voltage to the coil+

and assuming the test shorting the distributor connector to ground showed OK

Most likely is a distributor pickup bad
=================================

If the distributor connector "short" test did not produce spark

and jumpering 12V to the coil did not work

then it's a tossup between ECU and coil, whatever you can round up "cheaper."
 
I got home from work and installed the new coil and ballast resistor. The car fired right up. Is whatever happened to the first coil going to happen to the new coil? I took the same ride again tonight then let it run for about 15 more minutes with no problems. I'm going to get more familiar with my multimeter and begin learning how to troubleshoot under the hood. All advice is greatly appreciated! Thanks FABO.
 
-
Back
Top