I'm Neal and I am here to assist you. Only accept when you are happy with my assistance. If I can't help I will open your Question to other experts.
Have you checked the fuel pressure? Low pressure, even a few pounds can cause problems like that.
I have no effective way to check the presure. I have to go to work now and won't be able to provide any additional info at this time. I had this same problem in 2009. I spent time with another mech. we never did find an answer bases on what he provided to me. don't know if you can review the previous posts. ther eis a lot of information there.
thank you for your time. I'll check for a further responce when I get back.
PS. It's an 89 Iszue amigo pre OBD II ( it's a OBD I and there are no codes)