electronic EFI timing

[Gary John]

I am still having injector timing problems with a 1990 bronco II. I have learned that there are two electronic timing systems on the bronco II with a 2.9 liter engine. One is a random timing system that is regulated through the distributor and the other is a Sequential timing system that is also regulated through the distributor. The problem is, How can I tell which one I have? when I pull the connecters and test for current all the connecters are hot with the key on. Can anyone tell if there is a "Chiltons" that will give me the information I need?