Electronic ignition shutdown?

[Drew67coronet]

Alright guys, I've got a 1967 dodge coronet stock 318 2 barrel carb with electronic ignition. After driving for an hour or two and coming to an idle the engine will start to misfire very bad and cut off completely. Turn the key and starts right back up and runs fine for a minute or two and repeats the process. When driving it's perfect runs smooth as glass. Fuel filter is completely full, and when it stalls I will check the accelerator pump. Which is giving two very healthy streams of fuel, I don't think I'm running out of fuel. I'm wondering if my electronic ignition box is getting overheated? Or not a full 12 volts? I'm stumped. It's a NOS ignition box. I have a orange box but it made no difference when I switched them out. Any help would be appreciated!

Andrew

 

[pnora]

Sounds like the carb may have issues.

 

[Drew67coronet]

Sounds like the carb may have issues.

I hope that's all it is, I would rather deal with carb issues than electrical issues. Too lean maybe? Floats set too low? I'm not sure thank you !

 

[SattyNoCar]

How well is the ignition box grounded? I run a dedicated braided ground strap on mine from the ECU to the block and use an actual nut and bolt rather than a self tapping screw/bolt.

 

[Drew67coronet]

How well is the ignition box grounded? I run a dedicated braided ground strap on mine from the ECU to the block and use an actual nut and bolt rather than a self tapping screw/bolt.

It's got a 4 gauge ground wire going directly to it

 

[451Mopar]

The ECU sounds ok. I would start with checking the reluctor to pickup clearance, then the ballast resistor and ignition coil

 

[Drew67coronet]

The ECU sounds ok. I would start with checking the reluctor to pickup clearance, then the ballast resistor and ignition coil

Reluctor clearance is .008 ballast Is new so Is coil

 

[Drew67coronet]

Also only dies if I put it in gear or if I turn the headlights on the motor dies almost immediately, has new alternator too, maybe the wiring is in need of replacing? Too much resistance in the charging circuit?

 

[Don Frelier]

Try richening the mixture screws sounds lean to me.

 

[Drew67coronet]

Try richening the mixture screws sounds lean to me.

I'll give it a try!

 

[Dave6T4]

When was the last time your car had a new coil? I have had similar problems that went away after I put a new coil on. I initially thought I had had fuel problems too.

 

[Don Frelier]

When was the last time your car had a new coil? I have had similar problems that went away after I put a new coil on. I initially thought I had had fuel problems too.

see post #7

 

[70ChargeDodger]

Sometimes the reluctor pickup cuts out when hot, I would try another distributor if you have one.

 

[451Mopar]

Also only dies if I put it in gear or if I turn the headlights on the motor dies almost immediately, has new alternator too, maybe the wiring is in need of replacing? Too much resistance in the charging circuit?

Sounds like your voltage is dropping too low(?) with low RPM and higher loads.

 

[1toolguy]

I had almost this exact same issue quite some time ago, make sure you are using a low-impedance (0.8-1.2 ohms primary resistance) coil specifically for Mopar electronic ignitions. If it's an off the shelf "universal" (aka Chevy) coil it'll have too much resistance which will overheat the ignition box and shut it down. With any luck your ignition box is undamaged but, be prepared top replace it just in case.