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This was my first GM Drive~by~wire electronic throttle body mod, and also my first groove that needed to be RECUT. I didn't give this very touchy throttle body enough wiggle room for proper idle. So after installing, the idle went up as high as 4k rpm. It took over 30 minutes for it to calm down to 2k rpm. So I called Ron Hatton for advice! He did a great job at remaining calm, as I was highly stressed that the idle wasn't going down, and the customer was coming soon! He said that I might have to set the groove back another 1/8 inch. So I removed the throttle body, filled in the groove with JB~quick, and re~cut the groove. This time there was no issue, and the results were amazing! Not a hint of waste gas smell from the tailpipe, impressive power increases throughout the entire range, and after 2 fillups, the hwy mileage jumped from 17~21 and gaining with each fillup. ill post the latest when I hear back from him. The owner's wife was very pleased with the results aswell commenting to me "I barely have to touch the pedal and it just wants to go!" This technology only works everytime! This guy was so happy to experience this invention, he brought by both of his concrete finishing machines to get grooved. One with a Subaru 6.0HP EX17, and the other a brand new Honda GX120. I'll update you guys in the offroad section of the forum asap!
Gadgetman Foreston, MN
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Michael, I have done almost the same procedure with the groove and am now 1/8 of an inch from the edge of the base. What I have had trouble with is ECU conditioning...
I suspect I am not properly doing the band and ranging as well as WOT procedures. Any help with proper or your way ECU conditioning will be appreciated.
Any chance you have a picture you can share of the TB?
Also, here's a document for you to look over pertaining to re-educating the computer-throttle position - I've tried to upload it a few times, so if it's corrupted, I'll have to find another way to get it to you -but there's a TSB that may pertain to your troubles
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I took few pics of the TB, also I've read through the TSB. I did have a brief check engine light on but it went away before I had a chance to scan it.( This is my daily driver ). After the groove and conditioning I observed no HP gain neither MPG rise, in fact, my MPG dropped from 12.7 to 9.4.
The vehicle is a 2009 GMC Savana 4.8L with 160k miles.
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The TSB details the re-learn once you've got the groove in the right spot, but see how it differs from the original procedure the TSB updates.
I think you may have used the plate's natural rest position as your groove location point rather than the idle position - it's a clean& shiny TB, but you use the carbon stains of a dirty TB to position the groove.
Ron's probably on the right track with the vacuum leak, but that groove looks to be too far downstream (and not to full depth with the large bit, either) to me.
You read the manual and about the business card trick?
I have read the manual and did use a business card, I've also watched the training video where Ron is doing a groove on a GM throttle body. At the end of that video there's a note that pops up saying there should be no more than about 3/16 of an inch between the base and the groove. My groove sits just shy of 1/8 of an inch from the base. I have also checked the depth of the groove and the bit since fully in the groove. According to the manual and the video my groove is where it needs to be, so probably my next step is to look for any vacuum leaks and then to recondition the ECU once more.
In the manual for ECU reconditioning there are ranges of 15-25, 25-35, 35-45 mph etc, if I understand correctly then each range I do would basically be driving 15-25 mph then WOT to 65mph then ignition off, restart with next range and so on?
Like Ron said in his other reply to you, we're here to help each other.
relearn - you've got the basic idea. (you let it idle up to proper operating temp/closed loop, before driving, right?)
I've done some research of my own on the WOT part (I drive a GM product of a similar year myself), and there's a key tidbit that depending on the roads in your area can be a bit tricky to adhere to:
after you achieve the top speed of the run at "WOT," you have to get right off the gas and coast to about 20-25mph before you touch the brakes - it's fine tuning ignition (and in some cases valve) timing and re-writing the fuel map.
Why is that key? well, touching the brakes changes the signal that the MAP sensor sees (brakes are vacuum assisted, right? that big pulse if you hit them messes with the process), and the MAP waveform is used to adjust ignition timing and fuel delivery.
the ignition off part writes what the computer just learned into memory, updating the stock/factory programming.
another thing about the GM OBD2 warm-up cycle - it tests the EGR at about halfway to operating temp from a cold start (In my case, just shy of where the needle hits the lowest temperature mark on the gauge: I can hear the 3 solenoids cycle -clickah clicka clicka) and THEN it starts listening to the upstream o2 sensor, which gives the heater circuits of that sensor time to get to proper temp as well. that's to compare throttle position, idle speed, timing, fuel delivery, etc for that day to the baseline you established with the re-learn drive.
except for on really cold days, this whole process should take less than 3 minutes. (see what the engine coolant temp sensor is there for now?)
There's a concept I'd like to get everyone thinking about, because it's where the 14.7:1 stoichometric ratio comes from: what's referred to as standard temperature and pressure, or a "standard day". That's 16 degrees C/61F and 29.92 inHg - your car's computer uses this as well.
lower pressure than standard means -literally- there's less oxygen in the air, so to maintain the 14.7:1, it has to deliver less fuel. temperature - lower means the air (meaning oxygen) is more dense and plentiful, so the computer needs to send more fuel to keep 14.7:1 (this is the big why behind your fuel consumption increasing in winter)
so - as a real world example: the temperature of the air here today is 26 degrees, and the pressure is 29.82" - when I turn my key to the run position before starting, the MAF sensor tells the computer "hey, it's warmer than standard" and the MAP sensor says "yup, the pressure is lower than standard" so the computer doesn't need to have the expected injector pulse duration to fire up. once the engine coolant hits the pre-set temperature, the computer starts to fine tune those injector pulse widths, which it verifies with the o2 sensors, and closes down the throttle plate, adjusts ignition timing...
the reason we have to take special care re-educating the computers of our cars after grooving them is because the groove makes special things happen to how an engine works, and the computer needs the time to figure all of that out. hopefully this reply has helped you put all of it more closely together in your computer too.
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