Chasing down smokiness and lack of power

[Old Goat]

You can buy/make pop testers online. I’m about to do so. There’s also plenty of write ups on how to tear down, clean and shim your injectors for good pop pressure. If you’re sitting on a stockpile of injectors like I am, it’s good to know how to tinker on them, in my opinion.

I read on a thread, this Forum or another don`t remember.
E-Bay, Amazon etc..... sells these Pop testers probably all made
in China.
He noticed there was metal from the manufacturing that was not
totally washed out. Be a good idea to disassemble one to be
sure it is clean.

I too have a pile of IDI Injectors I got from PNP.


Goat

 

[The_Josh_Bear]

Josh_Bear: How did you pop-test your injectors in the engine?

Keeping this in mind: For our indirect injection setup, we aren't really looking for spray pattern. Sure if it's way off to the side it's not good, but otherwise it's designed to just splash off the far wall of the pre-chamber and combust from there. Atomization is not a thing for us, it's supposed to stream and then atomize off the wall.

Because this is true, we can pop-test inside the engine as long as we aren't trying to do a leak-down test. Everything else can be done without pulling the injectors. Just hook up the tester and pump till it fires. Note the pressure, repeat 1-2 more times and move to the next one. You're looking for a crisp "POP" and for the pressure to build steadily until it does. I suggest doing pop-testing on the spares you have FIRST, which will give you a great idea of what's happening by feel and ear, then move to the truck.

Doing all of this will let you test them for firm pop, good buildup, and equal pressures(within 50psi is ideal). If you have a dedicated diesel pop-tester, I suggest filling your tester with ATF or your favorite injector cleaner for good measure. Plus it(ATF) smells better than diesel.
I modified a Chinese "porta power" pump for my tester, so I use the hydraulic fluid the tester already has.

You aren't looking for a given PSI unless you're using diesel. Just that they all pop at the same PSI, within 50 of each other. Buy a quality gauge for this, the cheapo amazon testers have poor resolution.