Technical question: WPS500X
We recently had a customer question come through our Support desk, regarding the WPS500X pressure transducer. Steve Smith, our Automotive Applications Specialist responds:
| Q: Hi – Can you tell me if the WPS500X can be used for dynamic diesel compression measurements?
A: Hi and many thanks for your question. The WPS500X pressure transducer has the ability to measure cylinder pressure on both petrol and diesel engines. The kit supplied with the WPS500X only includes adapters for petrol engines. Should you wish to use the transducer with a diesel engine, at present you would have to source a diesel compression test kit utilising quick couple connectors that you can link to the quick couple Foster connector of the WPS500X pressure transducer. We are planning to introduce a diesel compression test kit to link the WPS500X pressure transducer to AST or Sykes Pickavant kits, giving access to their wide range of existing diesel fittings. |
For measuring dynamic pressures with petrol engines, this is fine so long as the combustion is removed from the cylinder (injectors are cut from the cylinder under test). The WPS500X is capable of momentarily measuring the dramatic increase in cylinder pressure from idle speed to WOT (Wide Open Throttle) but not for prolonged periods of time i.e. monitoring. The same applies to diesel engines once you have overcome the adaptor issue.
For any compression measurement using the WPS500X the combustion process must be removed from the cylinder.
- The increase in cylinder pressure in either diesel or petrol engines must not exceed 500 PSI, and the battery compartment of the WPS500X must never exceed 80 degrees celsius.
Hello
What about diesel engines with piezo injectors?
This will be a big issue I think. If you unplug piezo injector on CR Diesel the engine will not start at all. You could perhaps perform cranking compression waveform capture with WPS500X and then move on to do running cylinder balance test using a scan tool (with disengaged smooth running correction). Higher end scan tools such as Autologic support this function and the results are quite accurate. Frank could chime in here and explain more and/or correct me if I am wrong.
can you trick the ecm into thinking it still has an injector attatched? maybe a spare injector that can be modified to be used on several systems?