FUEL PRESSURE AND VALVE ADJUSTMENT

[Rawze]

(01-09-2024 )JWEAVER Wrote:  Need help! I have a 2019 x15 performance series, truck started smoking and skipping, machanic done a cut in cut out test it showed cylinder three no change. They are saying its a burnt valve. Suggesting rebuilding at 500 thousand which im fine with if were solving the problem but im trying to figure out if the injection pressures are the same on the x15 performance series versus a 2017 isx engine or am i looking at different pressures? Weve read that these fuel pumps are or were causing a problem. Do the valves take the same valve lash as the 2017 isx? Thanks for the help willing to pay for help. Weve talked to numerous cummings care employees and have gotten several different answers and more confused now than we were to begin with and thanks again!

Sounds like a bunch of garbage to me.

A cylinder cut-out test is NOT a reliable way on its own to check to see if the head is bad. You may have legitimate issues.. but your post implies it would sound more like what someone that would rip you off, or has absolutely no clue what they are doing, would say.


== first of all, if someone thinks they have a valve issue in the head then the valve stem heights and clearances need to be checked to see if there are any abnormally recessed valves.

After that, the rockers+rocker shafts all need to be removed and then pressurize the head to 30-psi air pressure, each side at a time, on the intake manifold .. and then the exhaust manifold to see if the valves are fully sealing correctly. Find out what the leak rate is (should not leak at all in 10 minutes with all valves closed on either side).

Then pull the injector(s) and boroscope any suspect valve(s), etc. if there are concerns or issues, inspect the valve seats, etc.

I.E.> Find out and identify PROPERLY what any ACTUAL DAMAGE IS BEFORE PULLING THE HEAD OFF IT and stop guessing like blind damn mice!.

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Next.. some hocus-pokus crap debates about injection pressures have noting to do with valve seat issues. If the programming matches the ser# of the engine then the injection pressures are set correctly in the program for that engine and its injector(s). ... and if the pressures are not properly held by some knd of fuel problems, then there will be a history of alarms/faluts for incorrect injection pressure in thee ecm.

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Also.. is this engine de-mandated?. -- if so then you need to copy the program out of the ecm A.S.A.P. and e-mail it to me and have it properly reviewed. This is nothing to take for granted at all. More than 90% of all delete programs are absolutely harmful to the engine and will in fact cause damage like valve seats getting eaten up, dropped liners, cracked pistons, injector tip failures, turbocharger failures, and a myriad of other possible failures. The trucking industry is plagued with bad delete programming that destroys engines. Far too often, truck owners also assume like fools that 'their delete' is good until it finally takes its toll and causes some severe damage.

Lastly.. if you want to know what the valve lash should be to the rockers, etc.. then register your engine by its ser# on quickserv.com (its free) and you will have access to all the service procedures and manuals, all parts lookup, and everything else.