bad misfire and ignition problem.

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ratty dart 340

ratty dart 340

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Hello everyone. I recently drove my 73 dart sport down to get alligned. It has a 71 360 engine with electronic ignition. While in the shop I had them look at vacuum lines and the brakes as well as tune the carb. I recently installed push button start to bypass the key. It worked flawlessly with no misfires at all. And the alternater was charging and I measured about 13.5 volts at the battery. When i got to the shop it was still working fine and sounded great. It was there a few days and they couldnt seem to align it perfectly(different issue). Come today, the guy said he measured 18 volts at the battery when running. He pulled the car around and it sounded like crap..

we had scheduled to get new tires on in the parking lot next door, so we drove it there and tried to figure out the problem. We went and bought a new coil, ignition box, and a new voltage regulator. this helped slightly. We also chcked timing, plug wires and the whole 9 yards and still no luck. However, we did find that the jumper that connects to the distributor had been resting on the header and burnt the wires pretty bad. We replaced this jumper but had no luck. Is is possible that when these wires shorted out, that the distributor and or other parts could have gotten messed up? We have a new distributor getting here on monday luckily.

The engine seems to run slightly better when very advanced, and we have the carb tuned well enough to know that the misfire isnt just a bad air/fuel mixture.


Any help would be greatly appreciated. Let me know if the video links work.


Videos:
Video of car running

Another
 
You may have somehow developed reverse polarity in the distributor pickup circuit. AKA if you reverse the two pickup wires, this changes the timing relative to where the rotor is pointing to the cap contacts. This has become known as "rotor phasing." You can search that phrase, there are all kinds of videos, etc talking about that.

Your fancy pushbutton (and why did you do that) may cause a DIFFERENT problem

"The way things work."

In the old days, when you twisted the key to "start" the RUN circuit went COLD. This is true of Mopar, Ford, and GM. There HAS to be some power to the ignition to get it to start. With GM and Ford, this power was sent to the ignition via the "IGN" contact on the starter solenoid. But Mopar did this in the switch. They are IGN1 and IGN2. IGN1 is the "run" contact of the ignition switch, and IS HOT ONLY in the "run" position. The powers underhood loads like ignition, VR IGN terminal, alternator field, electric choke if used, etc etc.

Again, that power goes DEAD during start.

When you twist the key to "start" TWO circuits are alive. The "S" start circuit which engages the start relay and starter, and the IGN2 "bypass" circuit, which feeds hot 12V direct to the coil + for a better spark during starting.

When you got the idea for a push button, that no longer works. This means that your IGN power goes through the ballast during starting, and ALSO all the stuff such as the cluster etc is still powered in start, and that the coil does not get as much power during start for a good hot spark.
 
67Dart273 said:
You may have somehow developed reverse polarity in the distributor pickup circuit. AKA if you reverse the two pickup wires, this changes the timing relative to where the rotor is pointing to the cap contacts. This has become known as "rotor phasing." You can search that phrase, there are all kinds of videos, etc talking about that.

Your fancy pushbutton (and why did you do that) may cause a DIFFERENT problem
Click to expand...
Once I am at the car again I will take pics and go in detail how the push button is wired. We did it because we figured out the key issue but we just liked the push button and re-wired everything on the ignition coming into the car from the bulkhead. I am very convinced the push button is wired correctly, because we had good charging, no fires, no misfires, nothing was wrong… until today after the shop messed with it.
 
67Dart273 said:
You may have somehow developed reverse polarity in the distributor pickup circuit. AKA if you reverse the two pickup wires, this changes the timing relative to where the rotor is pointing to the cap contacts. This has become known as "rotor phasing." You can search that phrase, there are all kinds of videos, etc talking about that.

Your fancy pushbutton (and why did you do that) may cause a DIFFERENT problem

"The way things work."

In the old days, when you twisted the key to "start" the RUN circuit went COLD. This is true of Mopar, Ford, and GM. There HAS to be some power to the ignition to get it to start. With GM and Ford, this power was sent to the ignition via the "IGN" contact on the starter solenoid. But Mopar did this in the switch. They are IGN1 and IGN2. IGN1 is the "run" contact of the ignition switch, and IS HOT ONLY in the "run" position. The powers underhood loads like ignition, VR IGN terminal, alternator field, electric choke if used, etc etc.

Again, that power goes DEAD during start.

When you twist the key to "start" TWO circuits are alive. The "S" start circuit which engages the start relay and starter, and the IGN2 "bypass" circuit, which feeds hot 12V direct to the coil + for a better spark during starting.

When you got the idea for a push button, that no longer works. This means that your IGN power goes through the ballast during starting, and ALSO all the stuff such as the cluster etc is still powered in start, and that the coil does not get as much power during start for a good hot spark.
Click to expand...
Yes I follow you throughout that message. However, we had it running great with ballast and everything in place. I do not see how the push button could change how much voltage is being sent to coil compared to using the key if everything else is still the same.
 
May have left the key on too long when setting up for your push button start.

Can over heat the coil and then they start going bad.

Try another good coil and make sure to not leave the key on any longer than necessary.

That's the one drawback with your push button to start, your key needs to be on to supply power to things.

With the Key only original start it's: put the key in and go right to cranking for the start.

☆☆☆☆☆
 
George Jets said:
May have left the key on too long when setting up for your push button start.

Can over heat the coil and then they start going bad.

Try another good coil and make sure to not leave the key on any longer than necessary.

That's the one drawback with your push button to start, your key needs to be in to supply power to things.

With the Key only original start it's: put the key in and go right to cranking for the start.

☆☆☆☆☆
Click to expand...
All the key does is lock the steering column. There is no electrics at all connected to the key.
 
What supplies the on power to the push button, or does it stay hot all the time? And where is the inline switch to cut power to the ignition to shut the car off?
 
George Jets said:
What supplies the on power to the push button, or does it stay hot all the time? And where is the inline switch to cut power to the ignition to shut the car off?
Click to expand...
we have a switch panel with 6 switches. One switch is for ignition which supplies power when turned on
 
Sounds like the way the old farm tractors were wired.

Hot all the time push button, but a toggle switch next to the push button to turn on and supply power to the coil.

Edit: if this is so you need a ballast resistor inline after your toggle switch to reduce the power to the coil to 7 volts for the mopar ignition.

You do not want the full 12 volts going to the coil.

HEI conversions use the high voltage square e-coils and they run the straight 12 volts without over heating the coil.

Feel your coil after leaving your toggle switch on for 20 seconds. If your coil starts heating up, you need to get the ballast in line.
 
Last edited:
George Jets said:
Sounds like the way the old farm tractors were wired.

Hot all the time push button, but a toggle switch next to the push button to turn on and supply power to the coil.
Click to expand...
Yes that sounds correct I think. So is there something inheritly wrong with that for my situation? We had the car purring like a kitty and charging correctly. But something at the shop screwed something up. And the jumper wires happen to be burnt. We replaced voltage regulator, coil, and ignition box, and a new jumper. This is why i think it could have fried something in the distributor..
 
The wire to the coil that burnt, did you have to cut and reattach the wires?
If those wires were reversed, that has been known to cause the reluctor to be "out of phase" and does cause nightmares with timing as you have described .
Good luck
 
George Jets said:
See the Edit: on Post #9
Click to expand...
we still have the 4 terminal ballast in the original location, and hooked up. Isn't that "in line"? i will measure again but im pretty sure i have measured at the coil with it running and got around 7 volts.
 
ratty dart 340 said:
we still have the 4 terminal ballast in the original location, and hooked up. Isn't that "in line"? i will measure again but im pretty sure i have measured at the coil with it running and got around 7 volts.
Click to expand...
OK
Make sure the coil is not heating up as the engine is running, should be cool not hot.

If coil is hot, could be toast already from whatever wiring problem that went wrong.
 
ratty dart 340 said:
Hello everyone. I recently drove my 73 dart sport down to get alligned. It has a 71 360 engine with electronic ignition. While in the shop I had them look at vacuum lines and the brakes as well as tune the carb. I recently installed push button start to bypass the key. It worked flawlessly with no misfires at all. And the alternater was charging and I measured about 13.5 volts at the battery. When i got to the shop it was still working fine and sounded great. It was there a few days and they couldnt seem to align it perfectly(different issue). Come today, the guy said he measured 18 volts at the battery when running. He pulled the car around and it sounded like crap..

we had scheduled to get new tires on in the parking lot next door, so we drove it there and tried to figure out the problem. We went and bought a new coil, ignition box, and a new voltage regulator. this helped slightly. We also chcked timing, plug wires and the whole 9 yards and still no luck. However, we did find that the jumper that connects to the distributor had been resting on the header and burnt the wires pretty bad. We replaced this jumper but had no luck. Is is possible that when these wires shorted out, that the distributor and or other parts could have gotten messed up? We have a new distributor getting here on monday luckily.

The engine seems to run slightly better when very advanced, and we have the carb tuned well enough to know that the misfire isnt just a bad air/fuel mixture.


Any help would be greatly appreciated. Let me know if the video links work.


Videos:
Video of car running

Another
Click to expand...

Being this happened under someone else’s supervision the very first thing I would do is verify the plug wires firing order.
(Just in case no one mentioned it yet)
 
[1] Is it charging at 13-14v now? 18v is too high & may have damaged the ECU. This needs to be checked first.
[2] Do not see how p/up polarity could be reversed, as the plug/socket is keyed to prevent that. Reversed p/up is unlikely to run at all because it advances the timing 30-40* & is erratic. It can also affect rotor phasing, with the rotor directing spark to the wrong cyl.
 
ratty dart 340 said:
Yes I follow you throughout that message. However, we had it running great with ballast and everything in place. I do not see how the push button could change how much voltage is being sent to coil compared to using the key if everything else is still the same.
Click to expand...
I explained it to you if you read my post. The key in the start position, completely changes the circuit.
 
I didn't read all the posts. But here is what to check. There is a blue wire coming from the voltage regulator. Follow that wire into the harness and there is a factory splice. Usually that splice which feeds the coil and the regulator and other things corrodes. I found that to be the problem of the same symptoms you are having. Check the bulk head for corrosion of that wire first.
 
RustyRatRod said:
See post #12. :realcrazy:
Click to expand...
Not sure why he wants to do a push button start, be like new cars with no key, just a fob??

Better help him along to let him build his car the way he wants.

We all may learn something in the process.

Radio Check.jpeg


☆☆☆☆☆
 
101 Shotgun approach to troubleshooting :elmer::BangHead:
 
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