Hi everybody, im new to volvos. I aquired a 99 T6 with 100k.

It only starts and runs when i disconnect the battery then reconnect it again. It runs great and drives great until i shut it off, then it wont start until i disconnect/reconnect the battery again. I dont have any lights on and it runs flawlessly when it starts.

I checked and there is no spark when i try to restart it after shutting it off, it cranks but wont start

Any ideas what i could be?

Thanks for your help