FUEL INJECTOR TESTING
FUEL INJECTOR CLEANING
FUEL INJECTOR SERVICE
THE PROCESS...STEP BY STEP
(This is an internal page of the JAGUARFUELINJECTORSERVICE.com website)
If you would like to start at my homepage...please click HERE
Fuel injectors are highly suseptible to fouling from foreign particles. Foreign particles may be introduced from several sources as itemized elsewhere on this site and as below...
1) The injectors are fouled from "baked on" or "burned on" fuel additives, which impair the injector from providing a properly atomized spray pattern, and/or cause the spray pattern to be discharged off angled, and/or cause the injector seat to "leak", and/or cause the fuel flow rate to be altered.
2) The injector filters, and in some cases the injector pintles, may be clogged from foreign particles introduced from an improperly maintained fuel supply system. (ie. rust in the supply lines, rust in the rail, rust in the tank, degraded fuel hose, water in the fuel or the fuel tank).
3) The injectors may be contaminated from foreign particles, as a result of improper handling during customer handling, or the cleaning and testing process.
Avoiding item 1 and 2, as above, and mishandling, is a responsibility of the vehicle owner.
Avoiding item 3 above is my responsibility, and correcting items 1 and 2 above, is my job.
My shop area is carefully cleaned and maintained to avoid injector contamination, and the equipment is likewise carefully maintained, to provide professional results with every injector serviced, to correct items 1 and 2, and avoid item 3. One hair, or one speck of dirt or rust, can foul an injector. It really is that critical !
With the above said...following is a detailed explanation of how your injectors are cleaned and tested.
A) Injectors are received and customer information and injector information is logged. Customer receives an e-mail notification of receipt of injectors.
B) Injectors are externally cleaned of dirt, oil, etc., via a combination of petrol flushing, clean pressurized filtered air, and wiping and brushing. Injectors with external light rust, are wire brushed to remove surface rust and loose paint particles. Rusting that pits the external surface requires additional cleaning steps, and added labor cost.
C) Injectors are scribed with an identification number. This insures that proper recording and charting of each injector's performance is maintained throughout the servicing and cleaning. If customer had provided numbers on the injectors that correspond to engine cylinder numbering, we will maintain cross references, to faciitate customer's engine fault diagnostics.
D) Injectors can now be visually inspected for any obvious signs of external damage. Cracked or missing pintle caps, corroded electrical pins, external rust, etc.
E) Each injector is now tested for ohm resistance and shorted/grounded coil windings for conformance to mfg. specifications. Any injector failing this test is excluded from further servicing. We also check the condition of the electrical connections for rust/corrosion which may affect proper electrical contact, and current flow. If necessary, the connectors are sanded clean.
F) Pintle caps, filters, o-rings, spacers, hoses, bushings, (as applicable) are removed and discarded as injectors are readied for bench testing and cleaning. With filter removed, each injector's internal condition (as well as the filter) can be inspected for rust or corrosion. Internal rusting of the injector is usually non cleanable, although they may be cleaned to determine if the cleaning process will remove slight rusting.
G) Injectors are now mounted on the ASNU flow bench for a precleaning leak down test of the pintle/pintle seat integrity. The leak down test will also reveal any mechanical defects in injector body joints. Injectors are tested at 1, 2 and 3 bar during this test . Results are noted.
H) Next step is the injectors are tested for pre-cleaning spray pattern shape. The injectors are tested at 3 bar pressure. This test will reveal any distortion of spray atomization pattern, or a pattern which is off-angled.
I) The next test process involves cc flow volume testing of each injector. Injectors are dynamicaly pulsed at 50% duty cycle (half time on - half time off), normally at 3 bar, for a period of 30 or 60 seconds, and results are logged.
J) Injectors are now removed from the test bench, air and cloth dried, internally and externally cleaned of flow solution, and readied for ultra sonic cleaning.
K) Injector pintles are now submerged in a specially formulated cleaning chemical, while at the same time, pulsed, and subjected to ultra sonic waves. The cleaning process runs in 10 minute cycles, and cleaning may continue longer subject to results of the pretesting.
L) After ultra sonic cleaning, the injectors are retested for leak test, spray pattern shape, off-angled spray direction, and flow volume. No pintle leakage, matching spray pattern shapes and spray angle, and no more than 3% flow volume variation is considered acceptable for daily driving conditions. Post cleaning results are noted.
M) Pre-cleaning and post-cleaning test info is compared for each injector and cc flow rate % differences are noted for each injector.
N) Dynamic flow volume is averaged for the full set, both pre cleaning and post cleaning average flow for the set, and % average difference for the full set is noted.
O) Standard deviation for the full set is calculated, both pre cleaning and post cleaning, and the % difference is noted.
P) A post cleaning static (wide open) cc flow rate (for the set) at 60 seconds, at 3 bar, is calculated from the applicable above cc volume flows. 3 bar testing, at 60 seconds, at static (wide open) is the industy standard for measurement of injector flow rates.
Q) Injectors are now refitted with new filters, spacers, pintle caps, and o-rings. Injector hose can be refitted, and injectors reinstalled on customer's fuel rail, at an additional cost.
R) Injectors are pulsed and sprayed internally with a lubricant to prevent seizing during shipment or subsequent storage. Injectors are externally lubricated with a petroleum based jel to prevent external rust.
S) Injectors are carefully packaged and readied for shipment to customer, with a full written test report.
T) An e-mail is sent to customer with a summary report of the testing.
U) To view the form used and the details provided for pre and post cleaning testing Click here
As you may notice, the cleaning and testing is exhausive, and for a set of 12 injectors, on average, requires about 5 hours, to complete...excluding refitment on your rail, e-mails, writing reports, or preparation for re-shipment.
NOTE: Your injectors are tested at +/- 80 feet above MSL (mean sea level). Flow rates will vary at different altitudes. For an explanation of psi variations at altitude...have a look at this link CONVERSION
For Jaguar owners. With perhaps two exceptions, flow rate information for Jaguar injectors is proprietary between Jaguar Cars Ltd., and Bosch. The underlying reason is Jaguar Cars (now owned by Ford Motor Co.), wants you to obtain new injectors from your Jag dealer, as opposed to you substituting other injectors made by other injector manufacturers, or wanting you to know if your injectors are performing to factory specs. By withholding the flow rates, and other injector data, you are presumeably forced into a purchase from the dealer.
I have serviced many sets of injectors from Jaguar cars. Therefore, I have that information in my data. So, I know what they flow, and I know the other data. I know how your injectors are suppose to perform from the factory. It is easy (for me) to determine, after injector cleaning and service, if your injectors are within factory specs. Another reason, why you should allow me to test, clean, and service your injectors.
I have recently obtained a set of "insulator bushings"... also referred to as an insulator "top hat". Part number EAC 4403. It is the hard plastic/phenolic part that fits between the injector and the intake manifold on the XJ6 engine. This part is no longer in production, and no longer in stock...although the o-ring that fits on the lower end of the insulator bushing is available. Do not loose your insulator bushing. I am looking for a machine shop that can make this part...as a service for my Jaguar customers. If and when I can have them available, I will post on this site.
Go to Order Form Page to Order