trying to set timing
 

i have an 87 k5 with a 350 that ive been trying to set the timing on. the problem i have is the truck wont start with the advance disconnected. this is my 6th k5 so not much is new to me , but this has me stumped. any ideas out there

It is a vacuum advance right?
What happens if you start it then disconnect the advance?

no - computer contrled

On my old '94 yukon the timing had to be set by connecting to the computer. Is it the same case here?

Drove me nuts. Turned the distributor to adjust timing and could watch the computer adjust it right back.

This is something I found. Not sure about reliability but....LINK

fixed it - turned out it was my msd controler- had to bypass it. now i just dont know if the controler is bad, but hey the truck runs now . i took the controler out-- i guess " keep it simple stupid" rite