Hello, I just registered here. I thought I was previously but I can't find my old logbook. I've brought a couple F-150s back from the grave in the past few years. An 89' extended cab which I still drive daily. a 92' short box that favorite son drove for 3 years but finally cheaped out and is driving an Escort. So I sold the 92'. Now I'm working on a 97' that I bought out of Bonnie's barnyard, really I'm not kidding! This cuss is driving me crazy though. This sat for 2 years. It's a base model with the 4.2, auto trans, a/c and 4wd. I got it running a few weeks ago and it ran ok more or less. It was missing on 1 cylinder but I drove it out on the road a few miles and made it home on what felt like about 3 cylinders and a check engine light on. I pulled the fuel filter and had rusty gas come out. Changed the filter and it ran about the same so on the basis of Vince saying "it sounds like plugged injectors" I ordered in a set of rebuilt injectors and installed them (old ones were pretty nasty). The truck wouldn't start at all afterward. I couldn't get a reading on a fuel pressure test gage so this weekend I dropped the tank and it was spotless inside with maybe a tablespoon of water present so I dried it out and installed a new pump and now have 52 psi without the engine running. Now the sticker! When I tried to start it, it caught for a few seconds then backfired thru the intake (I think) and everything is electrically dead. EXCEPT for a clicking in the cab fuse box area that sounds like a circuit breaker making and breaking. I tracked it down to the GEM module by pulling out the 5 amp fuse and the clicking stopped. The fuse of course is not blown and tests ok out of the truck. Does it sound like the GEM module is toast? or like one of the outputs is shorted? I have like 1.7 ohms resistance to ground at the GEM side of the fuse terminal. Any thoughts on this?
I hate to seem like a drive-by shooter, I just cannot remember if I was previously registered. But man have I got a list of headaches with F-150s if somebody else has a problem, perticularly with the 87'-92' vintage. Thanks!

 

Check grounds - just in case
Check connectors - just in case

I'll try to pull out the service manual and see if there are any tests you can do.

 

Thanks, I checked all the grounds and connectors I could find. I called the local Ford dealer to day and talked to the service manager. I told him I had a 97' F-150. First question he asked was "doing goofy electrical things?" Uh yeah, actually nothing. He told me most of what I've already learned on the web. Seems these years and body styles had a perchant for leaking water down on the GEM/fuse block assembly and destroying them. They do several of them a year and Ford has been aware of this poor design since 98'. He said if I get the truck there, they will install a new (from Ford) programmmed GEM and have it running excellent for $487.00.
He went on to say a few of these a year leave there for the scrapyard as the customer won't put $500 into a 14 year old but otherwise good truck. He also stated that as this body style ages, stresses and rusts, they are seeing more of them each year. When I have this done maybe I'll figure out where the leaks are and maybe even put a plastic drip guard over the unit.

 

Well the appointment is made and I have to have this truck up to the Ford dealer on Tuesday. I really hope for $500 bucks this issue can be solved. Is there a common place that these trucks leak to nail the GEM module? Or is it a random thing with the GEM module as the bull's eye? Definently worth the hassle of looking for a leak and fixing it, than having it happen again. Any suggestions are appreciated.
Thanks