scamp80602
Life Long MOPAR Man
1975 Scamp 318 - no mods, all original.
Just started having issues that I've narrowed down to no spark. It's happened as follows 5 times now, thankfully, in the garage every time: When cold after sitting for 2-3 days it will start perfectly and after idling for about a minute, it will stop cold. At that point, no spark at front right plug. when trying to restart. If I wait an hour - sometimes less - it will start right up, and be fine - stopping and restarting multiple times with no problem.
No problem with starter circuit - turns over every time
Today, after reading several great posts here on the subject of no spark, I made sure my grounds to the ECU, voltage regulator, firewall, and alternator were sound, and checked continuity of the distributor mag sensor. I also took the service manual and made ignition circuit resistance and voltage measurements during normal operation - with the car running and then with car stopped with ignition on - so I could compare during failure mode. Voltage readings were not different at coil, ECU, and ballast when it did fail again - ignition on at the time of failure testing.
I have a spare ECU, and will sub that the next time it fails.
I think I did correlate starting with disconnecting the alternator on several occasions, but that was early on, and it may have been flooded just prior - can't be entirely sure about this.
What I've done:
new ballast, and plug wires just installed - cap, rotor, ECU, voltage reg, battery 1500 miles ago.
I don't suspect a distributor rotation issue - runs fine when it runs.
I do suspect magnetic sensor, and the coil - both original. I have both on order.
It would be so much easier to fix, if whatever it is just broke completely - I hate chasing intermittents.
Any other suggestions would be welcomed - Thanks!
Just started having issues that I've narrowed down to no spark. It's happened as follows 5 times now, thankfully, in the garage every time: When cold after sitting for 2-3 days it will start perfectly and after idling for about a minute, it will stop cold. At that point, no spark at front right plug. when trying to restart. If I wait an hour - sometimes less - it will start right up, and be fine - stopping and restarting multiple times with no problem.
No problem with starter circuit - turns over every time
Today, after reading several great posts here on the subject of no spark, I made sure my grounds to the ECU, voltage regulator, firewall, and alternator were sound, and checked continuity of the distributor mag sensor. I also took the service manual and made ignition circuit resistance and voltage measurements during normal operation - with the car running and then with car stopped with ignition on - so I could compare during failure mode. Voltage readings were not different at coil, ECU, and ballast when it did fail again - ignition on at the time of failure testing.
I have a spare ECU, and will sub that the next time it fails.
I think I did correlate starting with disconnecting the alternator on several occasions, but that was early on, and it may have been flooded just prior - can't be entirely sure about this.
What I've done:
new ballast, and plug wires just installed - cap, rotor, ECU, voltage reg, battery 1500 miles ago.
I don't suspect a distributor rotation issue - runs fine when it runs.
I do suspect magnetic sensor, and the coil - both original. I have both on order.
It would be so much easier to fix, if whatever it is just broke completely - I hate chasing intermittents.
Any other suggestions would be welcomed - Thanks!
