Injector leak test

[Hermjeji]

Tested 3 of the ISX we have, one CM 2250 and two CM2350 isx. The 2014 cm2350 failed the pressure test immensely, dropped from 29k to 21k in a second and down to 300 PSI in 30 seconds. The 2013 dropped gradually about 8000 PSI in 1 minute as posted previously, but the cylinder cut out test revealed nothing to me (back 3, front 3 ran fine, each piston ran fine too). Wanting to buy injector leak test kit, should I go with OEM from Cummins or does this one from Amazon do the job (or other places). Also if it’s dropping that much on the cm2350, any guesses?

3164001 Fuel Injector Leak Test Check Kit Alt. for Cummins ISX/Signature Engine https://amzn.to/3rTAP38

Cheers.