Factory injector pop pressure

[Matt's'93]

I just tested the pop pressure on my factory injectors that have 170k miles on them and according to my gauge every single one popes at 200bar. According to what it says on the injector they should pop at 245bar. Could this be a contributed to my poor fuel mileage? Or are they ok?

[RCCUMMINS89]

If your gauge is correct, then yes it could very well be why your mileage suffers.

Re pop them at 245 bar. 200 bar is actually very very low, the more I think about it that is probably the majority of your mileage issues.

Now after you re pop them correctly, you'll probably find that you will want to bump your timing a little too.

[BC847]

200 bar is actually very very low, the more I think about it that is probably the majority of your mileage issues.

But if you're looking for that last bit of fuel and have the air to support it, it sorta comes in handy albeit hasey at idle.

Just saying . . .

[Matt's'93]

So when you suggest that I re-pop them at 245 bar how do I do that if when building pressure they pop and release it at 200 bar? I am using a home made tester built from a grease gun and I can build the pressure up to 200 bar just fine but as the injectors pop it releases and I can't overcome the amount of pressure lost by the poping...

[nyford]

There is a spring with washers (shims) that control the pressure. I believe adding shims will increase the pop pressure. The springs do "set in" over time so the pressure can drop.

[RCCUMMINS89]

Correct, you need to add some shim(s) to reset them higher. Probably can get a shim kit through a Bosch dealer.

[Matt's'93]

Ok well I will try to get my hands on some if those and see where I can get with them. Thanks

[Matt's'93]

Does anybody know if I could use shims P-pump injectors? I have a friend with a used set I may be able to use the shims from if they would work.

[RCCUMMINS89]

If they are i/c injectors...... I'm fairly certain you can.

[PToombs]

Somebody used small washers in theirs. I haven't heard that they failed yet. But then, he may have been to ashamed to admit it too!

[apexfd]

Just to be clear then: the factory pop pressure is supposed to be 245 bar?

[RCCUMMINS89]

Correct