N14 injector diagnosis
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From: northwestern PA
N14 injector diagnosis
i have a cummins N14 460 with a bad injector, runs on 5 cylinders at idle and hesitates bad under load. question is, how do i diagnose which injector is bad? there is no trouble code on the computer and no way to tell with the scanner.
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From: Mustang, OK
Originally Posted by hovisimo
i have a cummins N14 460 with a bad injector, runs on 5 cylinders at idle and hesitates bad under load. question is, how do i diagnose which injector is bad? there is no trouble code on the computer and no way to tell with the scanner.
I dont know if you have a Centry, Celect, or Celect Plus engine. But, on a Celect and Celect Plus engine which have solenoids that control the injector you can do a resistance check of the solenoid. However, usually an injector or wire related problem will show up as a fault code where as a clogged nozzle will not. Unhook your battery and remove the 2 nuts holding the injector wires on the suspected injector. Measure resistance accross the solenoid. A good reading is .5 to 1.5 ohms. Anything over that and you have a bad solenoid/injector which must be replaced. If this check comes back okay, you need to ohm each injector wire on that cylinder to the 2 pin pass thru connector on the side of the valve cover. If this checks okay, then you need to ohm the wires from the pass thru connector down to the ECM. Injector 1 wire is at cavity 1 and 10, 2 is at cavity 5 and 14, 3 is at 3 and 12, 4 is at 15 and 6, 5 is at 11 and 2, and 6 is at 13 and 4
Before you make any measurements, measure the resistance of you multimeter wires by touching them together. Whatever reading you get, you need to subtract that reading every time you make a test to get an accurate reading.
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From: northwestern PA
monty, thanks for the info. its a celect plus (1999) and all i have is an echeck scanner. i think it is just a clogged nozzle because there were no codes when i checked it with the echeck, i take it there is no way to tell if its just clogged?
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From: Whitehorse, cultural hub of the universe..
Every Echek scanner I have run into has the ability to do a cylinder cutout test, normally under diagnostic tests, or some such heading. Also, OTC scanners have the same ability.
You can shut them down in batches of 2 or 3, or 1 at a time.
if you can find the right scanner settings, this is the easiest way, ( other than having someone else do it of course )
good luck
You can shut them down in batches of 2 or 3, or 1 at a time.
if you can find the right scanner settings, this is the easiest way, ( other than having someone else do it of course )
good luck
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