JimC25
Member
Hello, I'm new to this forum and Bronco ownership and am hoping for some direction on where to go with this. I recently picked up an '89 Bronco with a 5.0. Was told it last started a few months ago. I did all of the basic tests. It has good spark at the spark plugs and about 40 lbs. of pressure at the fuel rail. I tested the signal to the injectors with a noid light and sometimes I get a positive pulse and sometimes I get nothing. Also, when the key is in the on position, the test light shows positive current to both sides of the fuel injector plug. Compression test shows I have one very weak cylinder (70), but the rest seem good at 120, so I'm thinking it should at least start. Also, I can get it to start if I spray carb cleaner or gas in the throttle body, but it dies shortly after. Based on that, I think the problem is fuel isn't getting through the injectors because the injectors aren't getting a good signal to fire. So far I've changed the PCM, the EEC Relay, the Fuel Relay and the inline fuel pump. I also drained all of the gas and put fresh gas in the tank. I am thinking I may have a short somewhere that isn't letting the negative pulse get to the fuel injectors, but I haven't started chasing the wires yet. I spent most of yesterday chasing grounds around the engine bay and cleaned up all the ones that I found. Any ideas on what else should be checked or could cause this intermittent signal is very much appreciated! Thanks in advance.
