help my 84 928S won't atart
 

Today I removed the central control board to clean the contacts. I replaced everything correctly but it will crank but no fire. I disconnected the battery first to keep safe. I've checked the board twice and no appearance problems or miswired. The only plug I can't identity is this one. Help any ideas?

Could be Z-plug. It controls security system. Plug it back in or make a Z4 to Z6 jumper. You will see very tiny numbers and letters if you look closely. Try to post picture.
Good luck,
Dave

Yup it was the alarm. Bypassed it like you said and boom. Funny I had to so this on my 86 944 too. Thanks for the tip!!

Glad to help. It happened to me also.
Dave