As I already wrote, I had the injectors ultrasonically cleaned and tested according to the ASNU method by a local Bosch service agent in the winter of 2005. Even though less them 2000km have been driven since then, the risk of reusing them as-is simply is too high considering that the total cost of this project has exceeded the five figures in European currency by far.
Since another main engine-problem with another car in our fleet has raised questions about the quality and capabilities of the very same Bosch service, I wanted to have them tested by another company. My requirements were rather simple; (1) Inspection and testing the injectors as received and log the results in a test-report; (2) Carry out the I injector service and retest the serviced injectors and log the results in a test report; (3) compare the test results prior and after the injector service. This test-report is very important, as this is a main part in this dossier before starting the re-commissioning of #231.
Problem is to find a company who works that way; it is not difficult o find a company who offers an injector service, but not according to my requirements. Then in the summer of 2009, I read an article in the German
‘Oldtimer Markt’ about problems with fuel injection systems. In that article, the author used a 1970’s Mercedes Bens R107 350SL as an example to prove the effectiveness of the ASNU method that is widely used. The procedures and methods used for that example very much complied with my requirements so it did not take long before I contacted
Prickartz consult in Germany.
When I removed the injectors a few days after Christmas 2009 and prepared them for shipping, I documented each injector and marked its position. This allows me to compare the test results with the engine failure and hopefully draw some conclusions for the Failure Mode Analysis that simply is not complete without analyzing the injectors.
On last Monday, I received an Email from Bernd Prickartz with the inspection and test results of my injectors. Upon the visual inspection, he already found some abnormalities.
1: The internal filters do not comply with the type specified for the Bosch 0 280 150 201 injector.
2: The O-rings were not of the correct size
3: The injector enclosures were unpainted
4: The spray nozzles were not of the correct type.
5: The spray-image of all six injectors did not match the criteria.
After the required corrective measures, Bernd Prickartz carried out the ASNU cleaning service and retested the injectors. The result was that five of six injectors passed on all criteria (dynamic-and static test and spray-image). Injector number four (#4) was rejected though and required replacement. I agreed to Bernd’s proposal after which he ordered a new injector, tested it and updated the rest-report with the results. That was last Wednesday.
Already today, UPS delivered a parcel that contained seven injectors (the defective #4) and the six tested injectors (including the replacement for #4). The injectors were shipped with protection caps on both sides and packed in an encapsulating sealed bag.
The injectors themselves were also individually packed in a sealed bag.
It is nice to compare the injectors prior and after the injector service. The right injector is the rejected #4 with the incorrect spray nozzle. The left injector is the overhauled #1 with the correct spray-nozzle. I have to admit that the spray-nozzles is not the fault from the company who performed the injector service in 2005. They just cleaned the injectors and did not replace the nozzle, but they should have spotted that it was incorrect.
The rest is simple; placement of the injectors according to the imposed placement restriction based on the deviation of the average dynamic test.
All in all, I am very satisfied with the injector service from
Prickartz consult. With a price-tag of 30 Euro’s per injector, he certainly is not the cheapest, but the added value including a full test-report justifies the extra investment.