I have a 1993 Bronco 351W. The engine starts fine when its cold but is sluggish (but always starts) when the engine is warm/hot. I replaced all vacuum lines, replaced the starter because I read heat soak can be an issue, changed the battery cables and made sure they were grounded properly, & changed the fuel pressure regulator. No codes are coming up on the OBD1 scanner. I have run techron fuel system cleaner through it as well. Also has a new battery, if that matters. I will appreciate any suggestions as I am running out of ideas and don't want to keep chasing this. My mechanic skill level is new but becoming more experienced. Thanks for any help.
mileage?
Hook up a fuel pressure gauge and look at your fuel pressure after you turn the truck off. The pressure should very slowly drop, if it moves at all. If it drops noticeably in a short time, you may have leaky fuel injectors.
Cold engines need extra gas to start and run. Hot engines do not. Leaking injectors can basically flood out the mixture and can lead to extended cranking time.
Thank you. I'll check it out.