Injector Nozzle Swap
I finally attempted this! It was actually a month ago and it was terrifying; I had a couple of issues, but I am ready to talk about my nozzle journey now.
The car had been running great all winter. After the snow melted I started thinking about what to do it next. I knew I wanted to take some long road trips to some great get togethers and I wanted the car to look "better than the last time I showed up". Hence the used bumper, fender and hatch.
Then Impex Fest was announced:
World Impex TDI Fest: Saturday, May 21st, 2016
...and I got to thinking, now that I have this new turbo, maybe I should request a re-tune for more boost? So I started researching...
I was the guy who always said I would never go down the upgrade path. I was just happy to "wake up" the performance a little.
...but the more I researched, the more I realized that if I was going to pay for a tune upgrade, then I really should replace my original nozzles. They were certainly "worn out" anyway. Also Jeff had said that I could easily upgrade to the "next size up" in nozzle with the tune he had applied last year. It all made logical sense, even though the car was running fine, the nozzles are a wear item, and I like to replace worn items with upgraded parts when possible.
Great! Now I just had to decide nozzles to get. It took me two weeks to decide and also gather up the nerve to order a set of Bosio Sprint 520's:
What made me most nervous was the removal process. The only videos I could find on YouTube were of sweaty shirtless men hammering away at injectors trying to remove them. I ordered a slide hammer.
While I was waiting for parts to arrive I pressure washed the front of the engine one afternoon, then sprayed penetrating oil at the base of the injectors on two separate nights.
The day finally came when I had all the parts, had the time, and was ready to start. I moved the vacuum ball, removed my glow plug harness, cleaned my desk, put down some fresh paper towels and then made myself some coffee.
When it finally came time to pull the injectors, three of them came out with just a wiggle using my fingertips, and only one needed a couple of taps from the slide hammer. Good times!
The next thing that made me nervous was cleaning the injector holes. I had stopped at my local sporting goods store and picked up a 12 gauge shotgun cleaning kit with a wool brush and it really did a great job. This went way quicker and was way more fun than I thought it would be:
Next it was time to take the injectors apart. Here is a tip:
do not use a wrench to break apart the injectors! I did, on the first one, it slipped and mangled the heck out of the sealing surface! My heart sank only briefly. I did not panic. I got a deep socket and removed the injector cap. I regret now that I did not take a picture, I was too distraught with worry, and I didn't want to jinx myself. I thought I might have ruined a perfectly good injector. Here is a picture with a cap in the background similar to the on I had damaged:
I was too worried to take a picture of the actual damage. The file is your friend I reminded myself. I filed the marred corner of the sealing surface for about ten minutes until it felt smooth to the touch, then I found some extra fine grain sand paper, placed it on a flat counter top face up, put some oil on it and rubbed the sealing surface until I felt it looked uniformly polished. I was a little worried because the surfaced seemed to be machined with an ever so slight dish towards the center, and I had polished it flat, but I had to move on. I rebuilt all four injector bodies with new nozzles:
A month later the injector I damaged and repaired seems to have sealed just fine. I know this because one of the others did not, and there was a putt putt noise and soot associated with that one:
Here is the washer that did not seal, perhaps I did not torque the rocker arm down properly, I was being careful not to over torque them and I had done them by hand. I guess it was better this than break the rocker arm and have the injector fly out. Replaced this seal last night and there is no more putt putt sound! "Hurrah!" I yelled out loud on the test drive.
I had been pretty confident I had found the putt putt problem before the drive; you can see the soot on one side of the washer that did not seal in the four way picture below. The two top pictures show the top of the washer where it meets the injector and was leaking soot. The two bottom photos show the bottom of the injector, where it meets the head, and seems to have sealed. Again, this was not the injector that I had thought I had wrecked, so that was a relief!
There is definitely more torque and power available now. The car was pulling nice all the way to 4800rpm before the nozzle swap. Now, it pulls even better, and instead of holding the go pedal and waiting for speed to build it seems more like I am just squirting some torque, shifting, and giving it another squirt. My favorite observation is something similar to what I noticed when I bought the Honda Odyssey with its 250 hp and 255 ft lbs (and 4500 lbs curb weight), that observation was that you can pass with ease on a two lane road and it seems to take a long time after you let off the accelerator to get back down to the speed limit. The Volkswagen is almost as fast as the minivan now.
Looking forward to doing all of the cosmetic touch ups as the weather gets warmer.