How To Do A Cylinder Cut Out Test and Check for Weak Injectors. Cat, Cummins, Detroit.

Cylinder Cut Out tests are one of the most common tests that are ran on Diesel Engines, but many people are unfamiliar with what the readings mean or how to do a Manual Cut Out test to really isolate each cylinder. This video goes into detail on how to test for weak cylinders, dead cylinders, and other engine problems. The video then discusses how to test the weak cylinder for compression and valve damage. Please leave questions in the comments section below. Did this video help you save time or money? If so, consider sending support on Paypal, for the username and thank you very much for watching.



31 thoughts on “How To Do A Cylinder Cut Out Test and Check for Weak Injectors. Cat, Cummins, Detroit.

  1. I have a 3406e that ran very well and then it started a intermittently fireing put a injector in it ran fine for awhile then it started it again later down the road we did a cutout. And tried switching injectors 1too number 2 changed a little tried wiring harness both rocker box and motor to ecm and all sensors checked cylinders no issues that could find when it's loaded and pulling the missing and jerking get really bad only way to drive it is let off or push it down harder doesn't fix the missing but it pulls better 1300rpm to 1550 this missing comes on and sometimes a miss after I get off a ramp to pull up to a light it comes down to a idle it will miss I can't think of anything thing else to I've done everything

  2. I wish I had the capability to scan my 06 Cat C 13. It developed a mild skip so I changed both fuel filters and the skip never went away.
    Whats really crasy is ever since I changed the Secondary fuel filter the restriction gauge at max power goes to almost 5.
    Before I changed the filter it would reach 4 at max rpm.
    Love your vids man! Also the clown and buzzer is funny!

  3. I thought u were going to do the test with the engine shutoff to see if the injector solenoid were doing the noise they do…

  4. adept ape i was wondering if you had a video of any leaking injector o-rings with the truck running i have a truck that it is pouring oil out around a few of the injectors

  5. People who thumbs down your videos are knuckleheads. On another note, I had the pleasure or diagnosing and replacing my first ARD head on a C13 this week. Your videos helped me understand the system much better. Keep up the great work.

  6. Hey, awesome vid explaining what to look for. Would you be able to do a complimentary vid about a contribution test, how to interpret the readings and pin point bad injectors?

  7. I just got work in a mechanic shop. Small, disorganized and trucks keep returning. I have never seen them do such a test with a computer and the program, although they have one. So far I keep seeing the same trucks return within days for engine related issues. And some other trucks return with more issues that did not exhibit other problems. I think I am seeing first hand a hack mechanic shop where used parts are recycled, lack of inspection is an issue, lack of documenting work done, and impatient Owner. One truck in particular had a bad turbo and engine work done. Then it came back for more engine work and a new broken turbo. Then it came back with a blown piston sleeve. Catastrophic destruction. I expect it to be back again. And I have been at this mechanic shop for one month.

  8. I have a cat 3406e been overhauled recently with a new head and it’s getting a miss under load and has a little rough idle but usually when I’m loaded pulling a hill and if rpms are around 1400 or so and boost sits around 20-30psi it jerks the truck and bucks I have to either let off or press the throttle for it to smooth out for most part and also noticed once I get into the higher gears usually 12-13 gear the rpm climb really slow and takes very long build speed this is empty or loaded. Or if I keep it on cruise and it pulls smaller hill and gets back on to flat and boost starts dropping for about 35 around 30-20psi it’ll do same thing jerk truck back and forth and soon as boost drops below 20psi or so it’s smooths back out. Could this be a bad injector. Sorry if my explanation is all over place just trying figure how put it into words.

  9. Hey bro would love to get in touch with you I have a mxs c15 with some issue with no engine lights has power issues it has low boost and kinda sluggish it’s I’m buring a wick load of fuel I use to get 1000-2000km a tank, I have a local gravel truck!! The weird thing is a few times a day the truck will all of a sudden start to produce proper power again 40-50ps boost and will pull good and hard, then after about 10-15 mins or so maybe more it will be back down to having that sluggish low power again

  10. Volvo d13 2012 i shift
    I have vibration on 40 to 45 and 50 to 55 front of truck is shacking steering weickle too, and rpm nidalee jumping, i change cylinder head becouse of pitting on 6 injector cap fiting and change the 6 injector only becouse rest of are ok mechanics say, now truck is shacking again on same speed, they do test will driving the truck with computer on it and say everything shows good.Wath can be the problem? PLEASE HELP

  11. I had a bad injector and found it by disconnecting one injector at a time until I found the bad cylinder, The engine would run bad when cold and smooth out after it warmed up but then it started making a loud ticking noise, I took it to the place that re-built the engine and they had already replaced the injectors 3 years ago ( about 50,000 miles), they said I had bad fuel and my engine was pinging and was told to run it easy until I burned all the bad fuel out, charged me 440 dollars to change the fuel filter, water separator and air filter, that did not fix it so they told me to drain the tank and flush it, did that and still not fixed. Tank was clean. Disconnected the number 3 injector and the noise went away completely and the engine actually ran a little better, this is the awesome part, my uncle who I work for owns a packaging company and we actually do foam for a company called Diesel Products and a few years ago they dropped off a sample for us to package and no kidding I found it last week, it was my EXACT injector, 241-3238 popped it in, truck runs alot better but the injector is not calibrated to my engine so when I take off or it is at idle it runs ruff but smooths out pretty much completely at 2000 RPM, kinda like to much fuel until you get up to speed then all is good, now my problem is getting the injector calibrated, I no longer trust these mechanics. What do I need to flash one of these injectors because I will tell my uncle to go and buy it, can it be done with just the computer and software or do you need the CAT online service that is like a grand a year?? I bought a 2000 dollar GM computer clone for 400 bucks and it works perfectly, but I have to pay to log onto the GM website if I want to program anything, it used to be $1200 a year now they have $55 for three days. but all the troubleshooting functions still work. The computer itself is a clone but comes with factory software, If I just bought the computer can I calibrate the injector to my engine??? Thanks for all your help. I think this is the problem?? runs way better with the newer injector, maybe still have other problems??

  12. I have a scan tool that can do an IAP test and cyl. cut out but it wont show me any values
    (cheap autel peice of junk), if i raise the IAP to max and do the cut out test , will I be able to go by sound and feel as to whether or not the injector is weak or am i pretty much f&%ked without being able to read any of the values. from there I would do the other checks you've shown to single out it being an injector, very knowledgable and very helpful vids, keep em coming thanks.

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