Rough start on '92 Volvo

[jkeithsr]

He said the rought starts could be due to the injectors.
The mechanic gave me two bottles of techron. He said to put one bottle in for two consecutive fill-ups with premium gas.
And to bring it back if there's no improvement. There wasn't.
A friend is very high on SeaFoam. I'm half way thru a tank with this and one of two of the latest starts was much better.
Not so on the second one. Any ideas or advice before I burn out the starter would be appreciated. Thank you.