Went from guessing injector pop pressure by ear to a $40 bench tester, and my idle finally smoothed out | Diesel Mechanics - Freelance Forum - The Community for Independent Professionals
Went from guessing injector pop pressure by ear to a $40 bench tester, and my idle finally smoothed out
Had a 6.7 Cummins come in back in March with a rough idle and a slight miss that the owner swore was a fuel filter. I did what I always used to do, pulled the injectors and popped them on a buddy's old hand pump and listened to how they cracked open. Sounded fine to me, so I put them back and chased the problem for way too long. Finally broke down and bought a cheap pop tester with a gauge on it, around $40 off the tool truck, and the #4 injector was popping at 260 bar when spec is closer to 310. Couldn't hear that difference with my ear no matter how hard I tried. New injector, idle cleaned right up, and the guy was happy. I'm not saying the ear method is worthless for a quick check, but having a number on a gauge beats a hunch. What do you all use to bench test injectors, or do you just send them out and let the shop deal with it?