see my 2 posts on 11/26/05, 1989 chevy tbi for my problems then go to my
response to 87 gmc tbi won't start. I replaced the ignition control
module, truck runs fine. to replace go to autozone.com , repair info, look
up control module. napa store near me has equipment to check your module.
easy to replace 30 minutes. good luck, let me know how you did.