weak spark to none

[bbmopars]

I have a 440 with factory electrinic ignition.im gettin weak spark on the positive side of coil.when run i hotwire from battery to positive side of coil i get better spark.also in run position tryin to start with out hotwire i loose all spark,then it comes back when i let go of key.Anyone have this problem before or similiar?

 

[swies]

Had similar issue. Check the ballast resistor. If you are not sure about what that is, search this site and you will find all kinds of info. In crank mode your ignition gets full 12 volts. In run it goes thru the resistor and lowers that voltage. If it is bad or any of the connection are it will not supply enough to keep it running. Just my thoughts.
Or your ignition switch is bad and not getting the run voltage sent on its way. But I still am going with resistor.

 

[bbmopars]

Had similar issue. Check the ballast resistor. If you are not sure about what that is, search this site and you will find all kinds of info. In crank mode your ignition gets full 12 volts. In run it goes thru the resistor and lowers that voltage. If it is bad or any of the connection are it will not supply enough to keep it running. Just my thoughts.
Or your ignition switch is bad and not getting the run voltage sent on its way. But I still am going with resistor.

Oh ok i replaced the resistor. Im thinkin the switch

 

[swies]

Was it running before you replaced the resistor? Also, there are two different resistors if I recall. Make sure you have the right one.

 

[bbmopars]

Was it running before you replaced the resistor? Also, there are two different resistors if I recall. Make sure you have the right one.

Yah and its the 2 prong single wire resistor one

 

[swies]

Yah and its the 2 prong single wire resistor one

So there are other places to check. Under steering column where switch harness connects and at firewall bulkhead connector. If either of those has bad connection it will cause same prob. If those are good? Switch is next.

 

[bbmopars]

So there are other places to check. Under steering column where switch harness connects and at firewall bulkhead connector. If either of those has bad connection it will cause same prob. If those are good? Switch is next.

Ok i will have

So there are other places to check. Under steering column where switch harness connects and at firewall bulkhead connector. If either of those has bad connection it will cause same prob. If those are good? Switch is next.

Ok i will have to check and if i power goin it.i replaced the engine harness as well

 

[AJ/FormS]

I have a 440 with factory electrinic ignition.im gettin weak spark on the positive side of coil.when run i hotwire from battery to positive side of coil i get better spark.also in run position tryin to start with out hotwire i loose all spark,then it comes back when i let go of key.Anyone have this problem before or similiar?

What year? The early ones were a dual-ballast resistor, which has 4 connectors on it. The one resistor supplied the ECU with power, and the other was a step-down for the coil. The dual item has orienting notches cuz the ecu side is different from the coil side. It only codes right when the matching connectors are used.
Start with a fully charged battery. And a cold ballast resister.Put an analog voltmeter on the coil plus, and turn the key to run; the voltage should be within 1/2 volt of the battery.Now turn the key to crank. You should see the needle momentarily drop to zero, and then bounce back up to near battery voltage dropping with the cranking time.
>If it does this there is nothing wrong with the circuit all the way from the battery,to the start-relay, through the bulkhead connector,through the ammeter,the key switch,the #1 splice,back through the bulkhead again, thru the ballast and finally the coil, AND back to the battery thru the engine block.
But if it drops to zero and never comes back, then you simply move up the line to each connection point I listed, until you find the voltage. If you put the tranny in gear (automatics only), the starter won't crank.And if the starter won't crank, the Ecu doesn't fire either, cuz it needs signal from the magnetic pick-up/ reluctor.
If the voltage pops back up to some voltage in excess of 1 volts less than the battery(starter not cranking), then there is a high resistance connection somewhere between the coil and the battery, go look for it, same as before.
Happy hunting.

 

[swies]

What year? The early ones were a dual-ballast resistor, which has 4 connectors on it. The one resistor supplied the ECU with power, and the other was a step-down for the coil. The dual item has orienting notches cuz the ecu side is different from the coil side. It only codes right when the matching connectors are used.
Start with a fully charged battery. And a cold ballast resister.Put an analog voltmeter on the coil plus, and turn the key to run; the voltage should be within 1/2 volt of the battery.Now turn the key to crank. You should see the needle momentarily drop to zero, and then bounce back up to near battery voltage dropping with the cranking time.
>If it does this there is nothing wrong with the circuit all the way from the battery,to the start-relay, through the bulkhead connector,through the ammeter,the key switch,the #1 splice,back through the bulkhead again, thru the ballast and finally the coil, AND back to the battery thru the engine block.
But if it drops to zero and never comes back, then you simply move up the line to each connection point I listed, until you find the voltage. If you put the tranny in gear (automatics only), the starter won't crank.And if the starter won't crank, the Ecu doesn't fire either, cuz it needs signal from the magnetic pick-up/ reluctor.
If the voltage pops back up to some voltage in excess of 1 volts less than the battery(starter not cranking), then there is a high resistance connection somewhere between the coil and the battery, go look for it, same as before.
Happy hunting.

Listen to this guy. I was hoping he would chime in. Knows what he is talking about.

 

[bbmopars]

What year? The early ones were a dual-ballast resistor, which has 4 connectors on it. The one resistor supplied the ECU with power, and the other was a step-down for the coil. The dual item has orienting notches cuz the ecu side is different from the coil side. It only codes right when the matching connectors are used.
Start with a fully charged battery. And a cold ballast resister.Put an analog voltmeter on the coil plus, and turn the key to run; the voltage should be within 1/2 volt of the battery.Now turn the key to crank. You should see the needle momentarily drop to zero, and then bounce back up to near battery voltage dropping with the cranking time.
>If it does this there is nothing wrong with the circuit all the way from the battery,to the start-relay, through the bulkhead connector,through the ammeter,the key switch,the #1 splice,back through the bulkhead again, thru the ballast and finally the coil, AND back to the battery thru the engine block.
But if it drops to zero and never comes back, then you simply move up the line to each connection point I listed, until you find the voltage. If you put the tranny in gear (automatics only), the starter won't crank.And if the starter won't crank, the Ecu doesn't fire either, cuz it needs signal from the magnetic pick-up/ reluctor.
If the voltage pops back up to some voltage in excess of 1 volts less than the battery(starter not cranking), then there is a high resistance connection somewhere between the coil and the battery, go look for it, same as before.
Happy hunting.

oh ok i have a 71 dart 2 prong resistor type.

 

[bbmopars]

Listen to this guy. I was hoping he would chime in. Knows what he is talking about.

Alright

 

[AJ/FormS]

What ECU are you running? Orange, Chrome, Gold, or other.
If other, pop the connector off it and count the brass pins in there. If there are 5, then it if very likely that it should have a dual-resister.
But this matters not,right now, as it starts and runs on the jumper.
Do the voltage test. It will wring out the problem.

 

[bbmopars]

What ECU are you running? Orange, Chrome, Gold, or other.
If other, pop the connector off it and count the brass pins in there. If there are 5, then it if very likely that it should have a dual-resister.
But this matters not,right now, as it starts and runs on the jumper.
Do the voltage test. It will wring out the problem.

A ecu from autozone and it has 4pins.how do you do a voltage test?

 

[AJ/FormS]

A ecu from autozone and it has 4pins.how do you do a voltage test?

Post #8

 

[bbmopars]

Post #8

I found i had a burnt distributor wire.so i took it back to the store.Are the petronix iginitor distributors good like the 2 or 3 type? I see can bypass the whole factory electronic igintion setup them as to.

 

[bbmopars]

I found i had a burnt distributor wire.so i took it back to the store.Are the petronix iginitor distributors good like the 2 or 3 type? I see can bypass the whole factory electronic igintion setup them as well to.