Engine idles ruff
 

Last week changed out distributor an cap an rotor. Also new plugs an wires. I have a tag under the hood saying unadjustable timing an idle, done by computer. Check with ford an tried to look online but didn't have luck. So didn't bother with timing. Two days ago was hot an didn't think to check my coolant level an she was on the edge of overheating. Got home, parked her an left about 5 hrs later... Got a mile down the road an she was accelerating slow even tho my foot was down. Code 1507 came up so I changed out the iac still hasn't changed. It feels like the engine isn't going gas somewhere or something, checked both pumps an both are running about 53ish maybe 54. I don't want to lean against the injectiors but that's what I'm feeling. Thanks for reading this all. 96 f150 176000 miles

Which engine?

4.9 inline 6. Completely forgot about putting that. I read a thread saying a failed spark plug could do it. I pulled them an they all look good. But parts fail..