injector and high pressure pump test, return volumes

[PLohr]

Hello,
I just did the injector return test and the high pressure pump return test.

Does anyone know how much fuel volume a new set of injectors will return?
How much will a new high pressure pump return?

I am trying to make comparisons to new pump / new injectors to determine how worn they are. Is that a valid comparison?

The injectors returned 100 mL in one minute. 180 mL is the limit according to the test instructions.

The high pressure pump returned 700 mL in one minute. 1000 mL is the limit according to the test instructions.

Thanks for any help.

 

[BigPapa]

You’re in spec. Drive on.

 

[sag2]

Did you run the injector return test hot? Did you run it at idle with FCA connected or disconnected? The actual test is run with the DRBIII doing a fuel system override. It bumps up the idle and the fuel pressure. You can get close by disconnecting the FCA and running the test at idle.

 

[PLohr]

sag2,
Thanks for taking your time to help me.

• I tried to run the test while the engine was still hot. By the time I installed the test fittings and performed the tests, the engine was down to ~160 F. Perhaps I should try again now that I have some practice.
• I performed the Injector Flow Return Test (Page 264) mostly according to the instructions from the 2003 Powertrain Diagnostic Manual from Chrysler. It does not mention using the DRBIII to enable a fuel system override. The page that I followed is linked here. I say "mostly" because I didn't satisfy the engine temperature requirement.

Where did you find the testing procedure that mentions using the DRBIII to enable a fuel system override?

 

[sag2]

The procedure isn't in the early service manuals. It wasn't a function in the DRBIII until maybe 05-06. The best you can duplicate it is disconnecting the FCA. Don't mind the knocking with it disconnected.