timing issue, cant figure it out

[csdpb]

I have an 1989 300zx that i have been restoring, i look to you guys for help often and get great results. so thank you for all of your input.
my idle goes up and down 50 - 100 rpm's and the timing marks, when a light is out on it, bounce back and forth. im at a loss with this and need your help. all vac hoses are in good shape, and have installed new plugs and wires. all sensors are new. maf cleaned and tested to work where it is supposed to. please help. im at a loss.
thank you

[evildky]

surging idle is usually a vac leak, which can be many places other than the vac hoses, a little carb cleaner goes a long way to trackign down leaks, it can also be an iacv issue, which a little cleanign wiht the carb cleaner might well resolve