badOHtenTAHOE

hi i know its the Tahoe forum but seeing how im an active member here i thought it would be appropriate to ask about my Yukon being so close to the Tahoe. its an 01 Yukon slt 5.7l vortec motor and its up to about 280,000 miles and still running like a clock. tech 2 shows engine data is all normal did a starting and charging/ battery load test with the snap on d-tac machine and everything checked out. Lately its been having an extended crank to start only in the mornings. plugs and wires are brand new oem , oil is fresh. im thinking that with the miles there could be carbon built up on the valves or valve seats or maby in the combustion chamber thats causing this hard start. there are no codes besides a P0741 tcc stuck off that comes and goes but that's for another days discussion. would it be bad to run sea foam through the motor. i have heard mixed reviews about the stuff and really don't wanna push the wrong buttons if you know what i mean. i have seen people use it and blow the white smoke which is supposedly "cleaning" the engine. let me know what you guys think. thanks !

maxxman04

have you run fuel pressure test? changed fuel filter within last 20k miles or sooner?

badOHtenTAHOE

changed the fuel filter roughly 5k miles ago. no fuel pressure test done yet gotta see if theres a schrader valve somewhere i can hook up to but im assuming if that was the case of improper fuel volume it would happen all the time not just in the mornings one time a day.

maxxman04

never assume that logic prevails when turning wrench. always keep in mind that new parts, even quality parts, can be faulty right away. i have had fuel filters be more restrictive straight out of box than old filter. carbon is one of those that would cause issues more often, more than likely rule that out. i say more than likely tho, not totally. fuel injection is picky with fuel pressure. 5 psi drop from spec can equal car not running at all. other than the non start once in awhile, does yukon run and drive normal?

badOHtenTAHOE

Yeah runs great and I monitored the misfire data on the tech 2 and all cyl we're at 0 exept cyl 3 misfired once at 6000 rpm wile running the test