Jump to content

Lister jp injector pop pressure


sparrowcycles

Featured Posts

Hi folks, just a quick one. 

I'm looking at the injectors on prince as I have noticed a little smoke with a diesel smell. Have just tested the injectors and cleaned a nozzle that needed it but I'm wondering what the pop pressure should be? I have two almost bang on 2000psi and one a tiny bit higher.

 

Thanks!

Link to comment
Share on other sites

 If it is the BDL30S54 nozzle then the setting pressure should be 150 Atmospheres.  2208 psi in old money.

 Once on the engine they are likely to fall a little, as the springs relax.

Sounds like a couple of your might benefit from a tweak.  What does the pattern look like?  That is usually the best indicator of problems.

N

Link to comment
Share on other sites

4 hours ago, BEngo said:

 If it is the BDL30S54 nozzle then the setting pressure should be 150 Atmospheres.  2208 psi in old money.

 Once on the engine they are likely to fall a little, as the springs relax.

Sounds like a couple of your might benefit from a tweak.  What does the pattern look like?  That is usually the best indicator of problems.

N

Thanks mate, yes it looks like two might be a little down, I'll have a look at them.

 

One needed a clean of the nozzle but after that all them made a nice fan, I was quite surprised to see that they only have one hole! I did note that they may have had a little drip left once once the spray had ended but I think that may have been the hand pump tester that I was using.

The engine runs clearer now with only a slight mist from the exhaust.

 

Thanks! 

Link to comment
Share on other sites

Pop testers can cause nozzles to dribble because not all of them have a proper delivery valve with the snap shut and decrease pipe pressure action. If you have a spare injector pipe it can be worth while looking at the nozzles pattern on the engine pump. Any dribble there is an indication summat needs looking at.

N

 

 

Link to comment
Share on other sites

When testing injectors for dribble the procedure I was taught and taught was to dry the nozzle, take the pressure up to what the test card says of a bit short of the opening pressure. Hold that pressure for xx seconds (can't remember the time but I think it was 30 seconds, let the pressure go and dab nozzle with blotting paper and measure the size of the damp patch if any.

 

Can't see the point of trying to assess dribble when or after spraying.

Link to comment
Share on other sites

10 hours ago, Tony Brooks said:

When testing injectors for dribble the procedure I was taught and taught was to dry the nozzle, take the pressure up to what the test card says of a bit short of the opening pressure. Hold that pressure for xx seconds (can't remember the time but I think it was 30 seconds, let the pressure go and dab nozzle with blotting paper and measure the size of the damp patch if any.

 

Can't see the point of trying to assess dribble when or after spraying.

The point is to look at the whole injection system in action.  Dribble can be caused by hole erosion,  poor nozzle seating or by poor delivery valve function, for example. It can also show up possible wear in the pumping elements.

 

Not as good as putting the individual components on a Hartridge tester, or similar, but enough to steer diagnosis in the right direction.

N

Link to comment
Share on other sites

49 minutes ago, BEngo said:

The point is to look at the whole injection system in action.  Dribble can be caused by hole erosion,  poor nozzle seating or by poor delivery valve function, for example. It can also show up possible wear in the pumping elements.

 

Not as good as putting the individual components on a Hartridge tester, or similar, but enough to steer diagnosis in the right direction.

N

 

Nozzle erosion should cause an uneven sprat pattern and poor nozzle seating would cause dribble when tested as I described. I agree that a pop tester won't find a delivery valve or pumping element problem but that is an injector pump fault. The full injector test procedure is: set break pressure, check spray pattern, check back leakage (wear between nozzle body & needle), drip test. The last two can be done in either order. For completeness pintaux nozzles (BMC1.x) should also be  tested for auxiliary spray hole operation and pattern but that is not applicable for the injectors in question and its all but impossible to do with any degree of accuracy without an additions bit of kit on the pop tester.

 

I agree with the thrust of your post but can not see how dibble can be assesses during or just after spraying. In my view its a separate test, just like the back leakage I did not mention in my last post. I would also not be happy with advising someone  who  had no idea about their practical abilities to test an exposed injector on a running or cranking engine. However I suspect many of us on the tools have done that at times.

 

9 hours ago, sparrowcycles said:

Thanks both of you, that's good information, I will try Tony's tip and also see if I can dig out another pipe to check the spray pattern off the actual pump itself.

 

Just make absolutely sure that no part of your body gets in front of the spray.

Link to comment
Share on other sites

5 hours ago, Tony Brooks said:

 

Nozzle erosion should cause an uneven sprat pattern and poor nozzle seating would cause dribble when tested as I described. I agree that a pop tester won't find a delivery valve or pumping element problem but that is an injector pump fault. The full injector test procedure is: set break pressure, check spray pattern, check back leakage (wear between nozzle body & needle), drip test. The last two can be done in either order. For completeness pintaux nozzles (BMC1.x) should also be  tested for auxiliary spray hole operation and pattern but that is not applicable for the injectors in question and its all but impossible to do with any degree of accuracy without an additions bit of kit on the pop tester.

 

I agree with the thrust of your post but can not see how dibble can be assesses during or just after spraying. In my view its a separate test, just like the back leakage I did not mention in my last post. I would also not be happy with advising someone  who  had no idea about their practical abilities to test an exposed injector on a running or cranking engine. However I suspect many of us on the tools have done that at times.

 

 

Just make absolutely sure that no part of your body gets in front of the spray.

Don't worry I have tested injectors like this multiple times and am very much aware of any risks involved.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.