Last night I did a Groove job for a wonderful lady named Sharon Louise, who owns an '06 Subaru Forester LLbean edition. It has the EJ25 2.5L 4cyl engine, auto trans. This is a drive by wire TB. Sharon had said that she didn't want the vehicle to have such a big power boost right off of idle. She has to slowly back down a long dirt driveway at her place.
So, I acted accordingly. First order was to do a PCV re-route, and this led to a big surprise for me. The hose from PCV valve, actually leads to TWO manifold vacuum sources. The hose from PCV goes to a metal tube, that lead to the driver side, then to a short right angle hose. The short right angle hose then goes to the nipple on the intake. So, I pulled the short hose, capped the nipple on the intake man., then replaced the short hose with a longer one, tee'd into the driver side breather hose on the air intake box. OK- all good and straight forward.
After the TB was removed/ Grooved/ reinstalled, came the relearn drive. Shortly into that, the idle speed climbed to 1500 or more RPM. And persisted thru the drive/stop/restarts. then the check engine light comes on...
huh?
Back in the driveway, raise the hood, start looking again. The metal tube for the PCV, turned out to have a 90 degree junction leading to ANOTHER man. vacuum nipple! So, I pulled the right angle short hose there, and capped both the nipple, and the open end of the metal tube. What Subaru had done here, was give the PCV valve a man. vacuum source, on each of the 2 cylinder banks. To give a more even pulse to the PCV I guess. I pulled batt. negative gable, waited a couple minutes, put it back, and resumed the re-learn process. All OK now, normal idle speed about 800RPM, no more check engine light. Lesson learned!
For the Groove, I played it conservative. I put 3 pieces of thin card stock in the plate gap opposite the Groove side, and used a Medium bit. That went well, no difficulties. This put the Groove significantly downstream of closed idle position.
I drove the Forester 'round the neighborhood before working on it, and found it has a nice off idle power. This, plus Sharon's request, gave me the strategy to use. With the PCV issue fixed, the re-learn drive showed a docile idle/off idle response. Followed by a nice fat power band that simply doesn't quit. At about 20% throttle the power is significantly boosted- and Smoothly! The power just ramps up all the way. Easily managed idle/low speed behavior, after that it's like Liquid Power! Full throttle from 45 MPH, it growls, and says, Let's GO! I was quite pleased w/ the results on this car.
Oh, and the tailpipe, it's a Dryer vent, just a hint of smell...!
I expect to receive feedback from Sharon Louise. She does a lot of highway driving, so I will report back w/ her feedback.
Thanks for directing her my way, Ron! I may get referrals from her too....
Tracy G
