Anyone With Experience Using Bosh style Injector Pop Tester?

[mrbornery21]

I need your input on using one of these pop testers. I bought one brand new and I am using it to test my new Bosh SD311 6.5 Turbo marine injector tips.

1.If I pull the handle slowly three of the injectors break at 1700psi and the other five break at 1800psi. This way seems real accurate. but there not popping at 2,200.psi

2.If I pop the injectors really fast, "Like the guy at the local diesel shop", they seem to be popping at 150 Bar or around 2,200.psi. But this way seems less accurate because the needle is moving like crazy! its hard to get an exact popping pressure. the faster i pull the higher the psi the slower i pull the lower psi, it seems that if i pull the handle really really fast the gauge goes all the way up to 2800psi

Just wondering if im using my pop tester right, cause it didnt come with instructions. I need your experience and help, give me some pointers thanks

[Slim shady]

I have an OTC pop tester and you pump the handle slowly to get the pop off pressure, This gives you an accurate pop pressure. Now if you are checking spray pattern you pump the handle fast to get an accurate spray pattern,

To check injector leak down you should have a valve to close and hold the pressure you have built up in the injector line. Usually you get within fifty to one hundred pounds of the pop off pressure and close the valve and see if the injector leaks down quickly or weeps a lot from the injector tip. Acceptable weep is a drop of fuel on the injector tip but the drop must not drip.

This is the procedure for determining proper injector pop off pressure, spray pattern and leak down. I hope this helps.

[mrbornery21]

thanks slim ill give it a try

[Slim shady]

The thing to remember is that spring pressure dictates pop off pressure. The spring pressure should be consistent at all times. that is why slow pressure build up gives you an accurate determination of pop pressure. Spray pattern is based on fuel flow after the injector opens,that is why pumping fast gives it a little volume after the pop off.

WE were taught to build pressure just below the pop off pressure then raise the handle all of the way to the top and press down quickly to determine spray pattern. A little trial and error doesn't hurt and the good thing is you can't hurt the injector. You need to get shims to set spring /pop off pressure. The key is to get the injectors as close to one another as possible. Take the highest and make all of the others as close to that as possible.

If you have questions let me know pm me.

[mrbornery21]

you know where i can buy some shims on-line

[Slim shady]

Depending on your expertise, you can make your own. I doubt very much you will need over 15 thousands thick for any shim.

Buy some hardened shim stock and use a hole punch to make your own. This has worked fine for me in the past. MCMaster-Carr has shim stock. Look them up on line they have about everything you could need, including the hole punch set.