TOPIC: 2002 Suburban 5.3 My First Groove!

I took a short trip to Reno to visit my new friend Tracy G. What a great guy! THANK YOU Tracy for being so generous with your time and knowledge! Finally got my feet wet and grooved a Junk Yard TB then went after my 5.3. Before I left I capped the PCV and went from 15 mpg to 16.7 mpg (thats on 18" wheels so is actually higher)

When we took the TB off the intake opening is oblong for the Gas vent and AIC.








Time to get groov'in. I did my first pass with the medium bit then hit it with the large. I blew a couple holes due to the wall being thin but we epoxied it up. Some epoxy got near where the pentil seats so I cleaned it off with a screwdriver but managed to score the seat a tiny bit.







After reshaping the groove from the epoxy we intalled the TB. I capped the crank vent port on the passenger side of the TB. The PCV line I re-routed to "t" with the crank vent hose and then directed them into the breather. Hoping I don't get any oil aspiration into the breather so will check in a few days.






On my return trip I had NO GAIN on mpg and NO POWER boost from the groove. When I spoke with Ron he said he sees these either get 40% gain or 0% gain. He recommended I check for leaks, which I did with starter fluid and had NO SURGE = NO LEAKS.

Any ideas why I had no gain? I'd love to figure this one out.

Hope this helps you Chevy lovers!

Blessings to you all!

Tim
Gadgetman Redding, CA

Hi again buddy! Well obviously you got home OK despite shaky ground!

Ya know I've been wondering also 'bout the IAC, since we really didn't do anything w/ it except clean it. My scantool doesn't have a readout to do with IAC %, I don't know if there's a way to extropolate that. Might try hooking up a vacuum guage for both idle, and driving it, just run a vac. line inside and place the guage where it's visible?

Idle was a bit rough at first start up, and we cleared that misfire code which didn't re-appear. Is check engine light still off?. The Groove you cut looked just fine to me,, does anyone else have input on it as you see it? Idle smoothed out OK during idle part of re-programming. I still suspect Ignition issues. Lotsa miles likely on those plugs in there. Can't help but remember your comment on a rough vs. clean lookin' Groove...

Anybody else got input for Tim?

Tracy G PS Great pics, Thanks Tim!!

Yes, I do.

The first cause for vehicle failing to respond is found in the Oxygen Sensor. After about 50K (don't you guys read the stuff I put in the Manuals and the ?) they tend to become unreliable. The ECU responds by not utilizing it to alter the fuel maps.

The second cause is actually in the transmission for certain vehicles. With the slip rate of the torque converter, it steals the gains you would otherwise receive. This is common in the ca 2000 S-10's. The transmission steals the torque, so the power is never delivered to the tires, resulting in no change.

Still, your emissions will be down, your operating temperatures lower and your oil will last longer without a doubt!

Let's see what we can do about those fuel trims. Replace the upstream O2 sensors, clear the ECU and try again!

Glad to see you guys hook up!

Ron

Of course, this is all theoretical, but based on a good deal of my experience.

Hi Ron! I'm not yet so exp. in reading datastream info. Can you say--would you expect the O2's to switch faster, say faster than once per sec.? They were generally up/down within the 1 volt range, though it did seem like one of em was slower than the others.

So Tim, here's where the advice about o2's applies--get 'em from the dealer or at least OEM ones.

I remember another issue that might apply on this one- vacuum supply to climate control. Karl and Ron spoke before about how Climate control can develop vac. leaks in the under-dash stuff. Might try finding/temporarily capping the vac. supply to it. See if manifold vac. changes. Also could hook a Mityvac to the supply line, pump up see if it holds vac. Would be a sneaky vac. leak!

I remember those sharp lookin' 18" wheels/tires, so what is stock size? If substantially smaller dia. then engine is under greater load under all conditions except straight flat cruise?

Tracy G

Ron,

I have the upstream O2 sensors coming (I got the Bosch Super Class)for both the 02 Suburban and the 01 Silverado- It called for the same sensor and I got them much cheaper from an online Co called .

O'Reily's wanted $67 each and I got them for $38 each from DW. They will take a couple days to get here but worth the wait for the money saved.

Since the Suburban is actually running worse, I'm going to check again for a vac leak. Otherwise I have to wait for the O2's - re-set the ECU and see what happens.

Thanks!

Just did a thorough check for Vac Leak by both starting fluid and a vac pump to the Booster. No leak detected.

Tim, have ya pulled any of the plugs or Ohm'ed out any plug wires yet? I'd be Real Interested to see a pic of a plug tip, what the gap is now, and how many ohm's on a plug wire..

You say it's running worse now? In what way?

Tracy G

Just installed the Torque Master (Star) plug and ohm ed the wires. All the wires were at .950 ohms

My wife says there is still a lack of power from 25-55. Doing a short trip soon and will see what the mpg is. Might still be the ECU calibrating... not sure

Hi Tim,

You may be a smidge too close with the groove to the idle position of the TB.

I have 2 TB's for my 2007 Avalanche and was experiencing the same thing.

Grooved the second one a millimeter farther out and got all that back and then some.

Keep in mind my 07 is a fly by wire TB.

Interesting that "maybe" becomes part of a calculation...

Karl Fortner
Tacoma, Washington

Karl,

Thanks for the feedback! I wondered if it had something to do with the position or roughness of the groove. The cable sets the plate totally closed so that's where I cut from. It was not a super clean cut being my first time. I might should find another or refill and groove again.

I'm a bit concerned about filling & re-grooving with the possibility of a small piece of JB coming loose over time and dropping into a cylinder. I can buy a new TB that actually comes w/o the PCV connection for $52 shipped from ebay. Junk yards want $75+ and the u-pull yards want &40 plus core plus tax. Might do that-

Really appreciate you taking time your time!

Tim Talbot
Redding, CA

It's been almost 4 years since Tim Talbot came to Reno. We had a great time learning and working on his Suburban. After re-reading this thread, I have more to say about it, though it's guesswork at this point. First, I think Tacoma Karl was correct about Groove placement at the fully closed plate position. If we had used Ron's business "Card trick" to hold the plate 2-3 MM open- the Groove would have engaged off-idle. This would have given a power boost closer to where the heavy Suburban needs it. There is likely a huge loss in the transmission and rear axle, that gobbles up engine power output.

I don't remember exactly, but there were big 18" wheels on this Sub. If the wheel/tire combo is taller than stock, that forces the engine to work that much harder in acceleration. And I bet this and most other BIG SUV's spend a lot more time and miles in city/suburban conditions than the open hiway.

I and we haven't heard from Tim in maybe 3 years. Too bad he's a really nice guy, and smart too!

Tim did a great Groove job on this TB, it's always perplexed me re: his results!

Tracy G