Well, ...it has been an interesting weekend. I accomplished the first groove on a Volvo 940 Turbo. I test drove it and it seemed to have more power...but I think I may have groove it in the wrong place. I viewed the video again and accomplished the Groove on my 2001 Century, which has the 3100. This engine is almost identical to the 3400 engine the video shows. I test drove it and it seems to have more power as well. I will post the gas mileage differences hopefully in the next couple of days. I did the change for the idle control valve also. I'll attempt draw this out and attach later. Hopefully I accomplished this correctly as well. I had to take the TB off three times because it would not idle. I eventually opened up the new groove for the ICV enough for enough air for the idle.

I have adjusted the gap for the plugs on the Volvo. Still need to accomplish on the Century.

I'm Looking forward to the results.

Bob G.

The idle will settle down, so long as The Groove is in the correct position.

When you first start the engine post-mod, just don't touch the gas pedal. This gives the computer time to start making its adjustments without passing the Groove, which can throw the ECU into conniption fits!

Do quite a few restarts, not touching the pedal until you're ready for the test drive. 9 times out of ten, any issue the ECU may have had is gone by the time you get to the drive.

The exception is if you've cut too close to the plate on computer controlled throttles. If they race to 2500 rpm or more, then idle down, The Groove is too close.

Hope this helps!

Well, sorry for not posting anything during the week. The Volvo and the Century both have noticeably better performance! Neither have improved gas mileage. I am going to look for vaccuum leaks this weekend. The fuel prices went up here by approximately 10 cents. The rumor mill has it that the price will be up by an additional 10 cents in the next week. Incredible! Well, let's get Groovin' and put a little dent in the greed! Thanks again for the support here. Hopefully I can get the "kinks" out of these two mods so that I can help others.

Bob G.

It has been a while since I accomplished my Groove(s) and I haven't accomplished the report because the work I need to accomplish must not be complete. There is definitely more power in the 2001 Century (3100 engine) and the 1991 940 Turbo Volvo, as well. I am not seeing the fuel efficiency. Both vehicles have been consistently getting the same mileage they were getting prior to the groove. both are at approximately 22 mpg. I believe I have accomplished the idle valve fix on the 3100 and I have plugged the lines I believe I need to on the Volvo. The 3100 also has the "adjustment" on hoses accomplished as well. I apparently have not accomplished something or have accomplished something incorrectly. I will get pictures this weekend (hopefully I will be home long enough during the day to do this). Any suggestions? We (my family) have definitely noticed the additional power and the engines seem to be running quieter as well.

Hey Bob!
This sounds exactly like what just happened with one of Aron's earlier mods, John Powell. If you are like mamy first-timers, they are reluctant to cut The Groove full depth and/or to "cut the plate".

I recommend you inspect your work. What you will probably find is the bit does not go into the TB to the maximum depth. Just hook up your Dremel and recut The Groove and see how much more material comes out!

Let us know how it goes, and get hold of Aron to see the details on John's case.

You are doing GREAT!

Thank you Ron. I will accomplish this during the weekend.