requires an Injector Pressure Tester and a Drill Press. If you do not have these tools, let the injectors be serviced at a Diesel Service shop. Be
prepared to de-assemble and re-assemble the injectors several times. . I have bought my pop tester on Ebay for $85.00
- Injector Pressure Tester
- Diesel tester.jpg (28.34 KiB) Viewed 8630 times
injectors are over 200K miles, you'll need new injector nozzle assemblies regardless.
Warning: Use eye protection. Do not place any part of your body into the injector stream. It will cut through your skin.
Use these instructions at your own risk. I am not responsible for anything.
Precautions:
Work on injectors must be done as clean and dust free as possible
Do not disassemble more than one injector at a time to prevent mix-up
Never interchange parts from different injector assemblies
Do not touch the injector needle with bare hands. Use rubber gloves or oil soaked rug
Tools & Supplies Needed:
*Injector Pop (Pressure) Tester
*Bench Drill Press
*Bench Vice
*Air Compressor for compressed air
*22mm wrench & 17mm wren
*6" chisel
*medium size mechanics hammer ~ 14oz.
*anvil or a block of steel
*a small rectangle of aluminum or copper sheet metal
*BBQ Bamboo Skewers (at Target $1.59)
*small wooden block (hardwood preferred)
*1 pt clean diesel fuel with some oil added to fill the pressure tester
*a can of penetrating oil
Cleaning Procedure:
1) Install the TBT injector into the Pop Tester
2) Pump and notice the spray pattern and opening pressure.
3) Install the injector into a vice and using the 22mm wrench, disassemble.
4) layout the parts on a clean wooden board or rug
5) install the bamboo skewer into the drill press, shorten if to long ( 4"- 5")
6) carefully remove the needle from injector nozzle and set aside
7) Brush off the outside carbon build-up from the nozzles bottom with a brass brush.
Start the drill press and press the tip of the skewer into the nozzle hole. Clean both sides, 2-3min as shown in pictures.
- Injector inner parts
- Injector Rebuild1.jpg (94.14 KiB) Viewed 8630 times
- Skewer installed in drill press
- Injector Rebuild2.jpg (127.38 KiB) Viewed 8630 times
- Cleaning the injector nozzle
- Injector Rebuild3.jpg (82.77 KiB) Viewed 8630 times
- Cleaning the injector nozzle, other side.
- Injector Rebuild5.jpg (78.96 KiB) Viewed 8630 times
Remove the skewer from the drill press and install the injector needle, grabbing only the smaller part of the needles end with the chuck9) Start the drill and press the wooden block against the needle tip. If the wood is to hard drill a couple of small holes (1/32", 1/16") into it. Make sure you clean the whole tip.
- Injector nozzle needle
- Injector Rebuild4.jpg (65.19 KiB) Viewed 8630 times
- Cleaning the injector needle
- Injector Rebuild6.jpg (81.82 KiB) Viewed 8630 times
needle into the nozzle. Do not force it. Needle should sink into the nozzle body from its own weight. It the needle fails to sink smoothly from any
position, replace the whole injector nozzle assy. Blow off all other parts with compressed air. If the opening pressure and spray pattern was within
spec. you can reassemble the injector body (58-72 ft/lb) and test the injector again. It should start discharging with a sharp crackling/snapping noise at set pressure.
Otherwise continue to "Adjusting The Injection Pressure".
Adjusting The Opening Pressure
After a run-time of 100k miles the injection opening pressure will be lower then specified. My engine just turned 200k miles and my injectors tested
in the range of 1000 - 1200 PSI (69-82 bar) as opposed to 1800-1920 PSI (124-132 bar). I am pretty sure that this is a second set of injectors. So I had
to increase the opening pressure in the range of 700-800 PSI (48-55 bar). This is a trial and error procedure so be prepared to disassemble and re-assemble the injectors several times.
The regular service method of changing the opening pressure is to change the distance washers inside. For the home mechanic it is unpractical since it requires a bunch of different size washers that are hard to get, if at all. The procedure below doesn't require to change the distance washer. Keep the old one in place.
Procedure:
1) place the injector spring flat onto a piece of aluminum or copper sheet metal and lay it on a steel block or anvil.
2) place the chisel tip between the spring coil and hit it with the hammer. Just a light blow, not to hard. By spreading the spring, a higher opening pressure is achieved.
- Spreading the spring
- Injector Rebuild7.jpg (96.92 KiB) Viewed 8630 times
each blow and use different spot (coil) on the spring. Start with 2 hammer blows to get the hang out of it. Clean off the parts with compressed air,
reassemble the injector and test it with the pop tester. Always include the distance washer when reassembling the injector. It comes handy when
you have to decrease the opening pressure. I was able to adjust the opening pressure with this method to within 100 PSI ( 7 bar) of the specified
value.
4) Use new crush (copper) washer and heat-shield washer for final engine installation (12-15 ft/lb). I am open to comments.