I'v replaced a few parts on my 91 trooper. Its been setting for a while and I'm ready to get it back on the road. Me and my brother couldn't seem to get the timing right and decided to check the injectors to make sure they were firing properly. we took the fuel rail out and he held the injectors in while I turned it over and they all fired well except that they all fired at the same time and then paused only to fire together again and again. This explains why it was backfiring and couldn't get the timing right. We switched out the ECM and the distributor with ones from a working trooper and they still all fired/squirted at the same time. I would very much appreciate any helpful info on this mystery
thank you
Ben