i have been trying to figure out why the 5.0 is running rich.i tried to pull codes from it and the code puller isnt working. i tried it on a 89 conv. and it worked so its not the reader.the following parts are new; plugs, wires, oxygen sensors(2), distributor guts and module including cap & rotor.car has 50,000 org. miles. the code reader does nothing but beep constantly and steadly. the orginal story was the cars fuel pump died. they replaced it and it started to run rich after that. that was before i got the car. the dash board is a mess and not everything is hooked up. will that make a diffrence why i cant pull codes??? or maybe a relay somewhere. i have narrowed the code reader problem to the "store" wire. checked wire going to eec and its fine. there is no output coming from the computer on that wire. anybody have any suggestions or comments please feel free. considering im lost with this any bit can help.

 

Your car suffers from what alot of our cars do. D.P.O. (da*n previous owner) syndrome. Wiring is a pain, I wish you the best of luck. Have you read the tech article on running rich, here: https://mustangforums.com/m_2355308/mpage_1/key_/tm.htm#2355308

 

If it's running cold it will tend to run rich.... If it doesn't have a thermostat or a lower temp one, that can cause it (the DPO thing)...