Timing Issue Need Help

[DJ23GSX]

A buddy of mine is having a timing issue. When he shines the timing light down on the timing plate the tick mark on the crank pulley just goes around and around it doesn't stop on the plate like its supposed to. The timing light is hooked up to the #1 cyl the plug on the firewall is grounded and the datalogger cable is unplugged. Is this a timing light issue or a dsm issue? His idle is quite choppy too. All the timing marks linee up as well.

 

[killer_eclipse]

i would try a different timming light... but i had a similer problem with my friends car very choppy idle timming would tick would be all over the place turned out he needed new wires and he had a vacuum leak...

 

[DJ23GSX]

timing light is fine and works perfect on other dsm's. His crank pulley fell off yesterday so it must have been loose when he was checking his timing causing the mark to just keep going around and around.