2003 F150 4.6 Romeo 274,000 miles. Motor starts fine when cold, after warm-up it takes longer and longer to start vehicle As day progresses. New coil packs, all Timing components, Oil pump, water pump, thermostat, battery, starter. It was doing the same thing before all components were changed. Any suggestions

 

Before all the work, did you ever get a base line comp test on it being it’s a high mileage mill?
Fuel pressure/volume etc?
Prior to work, was the CEL on?

 

No it needed timing guides etc. while I was in there I replaced all the other things but never did any baseline checks

 

No baseline was done prior to work, Also replaced temperature sensor. I was told by another Ford owner that himself and a couple of other people have found there is a gasket on top of the gas tank that could be causing the problem with a bad gasket. Ever hear of anything of that nature.