440 breaks up at higher rpm's

[hemi01charger]

I'm running the mopar electronic ignition system and I noticed when I'm driving and get into it the engine starts breaking up at around 3,500 rpm. Then it quit on me one day at the gas station and would turn over but barely stay idling and would quit. Thought it was the ballast resistor, so I ran a jumper wire and bypassed the ballast resistor and it turned right over and ran fine. Replaced the ballast resistor with 3 different ones and still have the idling problem and breaking up. Coincidentally, running the jumper wire also got rid of the breaking up of the motor at higher rpm's. As long as I don't run a ballast resistor the car runs like a top. I assume I'm putting more voltage to the coil when not running a ballast resistor. Any ideas as to what the problem could be?

[elacruze]

First thought here is a bad coil. If the coil is shorted internally, it can still function with the pre-short windings to get along a little. Raising the voltage improves the output in any case so may put the weakness over the hump so to speak. It's possible you have some simple connection issues, first verify a good ground from the module to the firewall; do you have a tach, and if so is it jumpy? That plus an intermittent miss was my clue that the internal module ground had failed.

[4cruzin]

May be a fuel problem??  What size gas line are you running?   Where is your fuel filter located?  Do you have a fented gas cap?   

[firefighter3931]

Are you using an orange box ? If so, those are known to be problematic 

I'd run a resistance test on the coil and if that checks out....look at replacing the ECU 



Ron

[doctor4766]

Are you using an orange box ? If so, those are known to be problematic 

I'd run a resistance test on the coil and if that checks out....look at replacing the ECU 



Ron

True story?
Can that limit the revs under hard load?
What colour MP box is best?

[hemi01charger]

I've tried a different coil. I'm running a 3/8 fuel line. Edelbrock performer pump and an 800 cfm performer carb. I had an orange box on there. Tried a cheap box from the part store and even a Mopar chrome box and still breaks up at 3500 rpm and up. Only seems the car will run right when I bypass the ballast. It's driving me nuts. Have any of you guys seen the wiring harness that M&H make for the Mopar electronic ignition? They have you run a 4 ballast resistor and I tried that set up and my car won't even fire with it. 

[charger Downunder]

You might want to read this over at moparts maybe some help.
http://www.moparts.org/Tech/Archive/elec/3.html

[elacruze]

If you've exchanged both coil and module, look to the distributor. Be sure the air gap on the pickup is not too wide, and be sure they have not come in contact and damaged the coil core or reluctor. Mine came loose a while back, and wouldn't run much above 3000rpm.

[Cooter]

I hope your not running a Resistor type coil along with the Ballast Resistor. If so, your coil may not be getting but around 3 Volts. If running the ballast rtesistor, you need a NON resistor coil, if not running the ballast resistor, then you need a resistor type coil.

[Chryco Psycho]

is the rear air door on the carb adjusted too tight or stuck you could be runnng out of air on 2 bbls

[charger Downunder]

I hope your not running a Resistor type coil along with the Ballast Resistor. If so, your coil may not be getting but around 3 Volts. If running the ballast rtesistor, you need a NON resistor coil, if not running the ballast resistor, then you need a resistor type coil.

This might be easier.
Bosch GT40R Use with resister
Bosch GT40   Use without resister

[hemi01charger]

I had the black Mopar performance coil on there, but it went bad and I replaced it with a spare coil ny buddy had. It's a chrome Mallory coil.

[billschroeder5842]

Please post your results as my car is doing the same thing breaking up at 3500ish.