F150 Engine Light

Any of you guys know anything about '88 F150's with a 5 litre. I have one that's been sitting for about two months while I was driving my '89 SC for the summer and now it won't stay running when cold and the engine light is on all the time. I took the Idle Air Control Valve off and cleaned everything with throttle body cleaner, checked for vacuum leaks, put new fuel in the tanks and have been driving it for at least three hundred miles with no changes. Anyone know what I should look at next?

i would try unhooking the battery for 5 or 10 min to reset everything ,one time i had my throttle body off and it idled at 2000 for over a week till i unhooked battery then it took 3 days and about 200 miles before it learned to quit stalling at stop signs , or read the code that is stored in there and fix what it says

Change the Fuel Fi;ter. If this Helps doa good Professional High Pressure Fuel Injection Cleaning. Injectors and Rails are known to produce varnish when sitting too long.