My 97 7.3 has a rough idle and hesitation on take off or under light acceleration poor mpgs and a high pyrometer readings all the time. . we have done a new harness on one side that was burned and the other is ok and new o rings on all 8 injectors. new fuel filter ran a shot of lucas in bowl and changed oil and topped off. and a new airl filter. still has problem.. got better for 1 week after service and lucas fuel additive in bowl then went back to running like crap

 

Sounds like a bad injector. Any white smoke??