injector pulse width not changing

[TY417]

My friend has a 88 safari van that we can not get running right. It will start and move but runs like s**t. everything has been replace map, tps, computer, chip, fuel pump new tune up. All the reading with diacom, snapon and an oscilloscope are ok except the pulse width for the injectors that stays the same, even when loading the engine by power braking.

Any suggestions would be appreciated. My friend is about to junk it.

Thanks

Ty417