1.6 16v obd1 problem

[incision]

hi i swap an 1.6 16v 1994 on samurai friend's last years and ride good but this spring the samurai feel bad missfired when warn dont keep idle and stall. we find the return line was completetly block off, we fix it but problem still on. can it broke injector? timing belt was good the pump pressure are good too i change the sparkplug because they have lot of carbon powder on it.

other problem i try to read dtc code on the cluster but it dont flash when i jump the 6pin plug (near to the battery)?

iam totally overpass please help me!!!!