First let me say I am not a Ford guy. I don't say that to upset anyone, I just grew up in a family with a different affiliation. That said I am in uncharted water and could use some help from people that know more than I do. I inherited my uncles 1991 f150 custom. it is 2wd, 5sp manual, 4.9 I6, with 948 original miles. You read that right. He special ordered the truck, paid cash for it and then rarely drove it. It has set in his climate controlled garage for 31 years and was last started in 2006. So the first thing I did was to remove the plugs and spray some outboard fogging oil into the cylinders and let that set for weeks. After some time I began to turn engine over a few times by hand over a few weeks time. Finally it was time to see if it would fire. I new the fuel was bad so I unhooked the fuel lines at the filter to make sure not to pump anything into the system. Installed a battery and sprayed some fuel into air intake and she runs like a champ. Next I removed both tanks and replaced the pumps and tanks along with the filter and blew out the supply lines. I removed the injectors and cleaned them and did bench test to insure each was spraying as it should. I put some high test gas in each tank and tested for proper pressure at the rail (55lbs for each pump and it holds it overnight). Time to start. She starts up and I run it around my property and back into garage. I begin buffing out the paint from being stored so long. I get one side done and set to turn truck around to do other side. No start. Begin doing same test as before. still have same pressure, check injectors, check for fire, all are good. Starts with fuel directly into intake hose. Then I check the injectors with noid light.The odd bank is firing like crazy the even bank is not firing at all. I know that the ignition module sends a signal to the ecm which then sends a ground signal to the injectors. What steps do I need to take to test if the ignition module is indeed sending the signal, the ecm is doing it's job, and where to check for proper ground. I have checked the ground points I could find but not sure if there are connectors that need to be tested. I want to drive this truck down the road real bad. Please help.

 

It appears you are on the right track. Since it has sat so long, I would be looking at the injector wiring for those suspected cylinders from rodent damage.A vehicle which has set for so long can have MANY issues.There appears to be a circuit issue for those even banked injectors from the injectors all the way and including the PCM. I don't suspect an issue with your ignition module. Unless there is something wrong with the way the pickup coil is being pulsed by the ring in the distributor, I can't see how an ICM can single just those cylinders.I would like to see a couple pics of your "time capsule" since this truck is higher unusual considering its age and mileage.

 

yes, sounds like you're doing it right. This link has a diagram of the 4.9 from 1990 showing the grounds and odd/even firing banks. Should be the same as yours although I'm not certain.

https://www.ford-trucks.com/forums/1...eedometer.html

Raski had the same idea as I did when i first read your posting about the potential wire issues to that bank. Since you have almost no miles, it should look totally unmolested in there, so anything out of the ordinary should be visible. I too am looking forward to photos, and they may serve anyone coming through who has an older 4.9 with loads of "edits" who are trying to put it back to original.