I bought my 500l at an auction and it had an aftermarket distributor made by " 123 Ignition". Very high quality but I am starting to think it is causing a series of misfires (5 or 6) after the car had run about 5 minutes. The misfires then stop . Anybody have any idea what this might be. One theory is that when the battery is finally fully charged after the start the voltage regulator switches over and in the process delivers a voltage spike that puts the computerized distributor into protection mode for a split second. I am ready to believe it as I have checked everything else several times. Thanks, Nedsly