I saw some reports of wiring problems so I did check that out. I pulled the wiring out of the loom and pulled and wiggled on it and couldn't find any problems. I think I even messed with it while the engine was running with no problems.
It's kind of odd that the only time the code shows up is on a sustained WOT run at the top of 2nd gear usually around 85-95 mph. It has always gotten through 1st gear just fine.
I was able to duplicate the P1516 code in my driveway with the key in the on position and not running today. I put a heavy brick on the gas pedal and verified the TB was open 100% then lightly pushed on the blade in the direction to close it and found that it doesn't take much pressure at all to cause the P1516 code to show up and go into REP. Looks to me like it has nothing to do with the springs in the different TB's like people seem to think. I think the motor in my TB is too weak to handle high airflow turbulence. Could be a problem with the truck TB in general but I won't know until I get to test a new truck TB against a car TB. I have access to a new truck TB but not a car one so if the new truck one works I won't be spending money on a car one to test it, unless someone wants to loan me one.
Last edited by truckmann; 01-09-2010 at 03:25 PM.
Picked up a brand new l92 truck TB today and put it on. So far so good, it logs to 100% now and I haven't gotten any DTC's yet. Hopefully the older TBSS TB I had was the problem.
Keep us posted. I am interested in your final conclusions.
2003 silverado SS, 11.72 @ 114.
Still working fine so far and it idles better too. I don't get a lot of chances to run it up to 100 mph safely, but so far when I have it has worked fine. I also did the push the blade closed from WOT in the driveway test again and it seemed to take quite a bit more pressure to get it to throw the code and go into REP.
The temperature has warmed into the 50's here. I would like another day of cold weather to test it in since the cold dense air may make a difference. Although I was having troubles with the other TB even at this temp so I'm optimistic that the problem is solved.
Still working fine?Originally Posted by truckmann
Yes it is. I still haven't gone out to the track, but I have not been able to make it trip the code on the street. I idles a lot better too, although there is still the occasional off idle surge I'm trying to get rid of.
Just the fact that it actually logs to 100% now in the scanner makes me confident this TB works much better than the other one. I guess I'm still reserving my absolute final opinion until I get out to the track, but I'm about 99% sure the problem is solved. The sensor in the TBSS TB I started with must have different specs or be out of spec compared to the new L92 TB.
So you replaced the TB with a same part number new TB and it was AOK?
Heard GM may have had some quality issues with early 09 TB's but never found any back up information.
Yep same part number. The only difference was the old one came from I think a 2006 TBSS with the intake I bought and the new one was brand new. I bought it from a friend who got it for a project probably last year sometime and ended up not doing what he was planning.
What kind of gains did you see with the TBSS intake and TB?
Contemplating this swap on my LQ4.
I really don't know. I haven't had it on a dyno since the change. I know that it feels better, but that is subjective. I hope to get back to the track somtime soon and see an improvement there. My first attempt at running it down the track after the swap didn't go so well since I could get all the way down without the TB problem.
Here is some info from someone who put one on an LQ4 and got 15whp and 18tq bottom to top.
http://www.performancetrucks.net/for...d.php?t=455536
Unless something happens I plan to go to this Dyno Day GTG on May 29th to hang out and see what my current numbers are on the dyno.
I re-tuned a 2006 cammed 5.3 Z71 that put a TBSS intake on. He bought the TB separately (not sure what year it came from) and at WOT showed 96% TPS, idled rough, and REP showed up every WOT pass but only at the top of second gear. I found this thread while searching for how to tune it out. I was skeptical at first. I took my TB off of my 2010 Sierra (same PN#) to try it before wasting money. REP is gone, WOT = 100%, and it idles noticeably better!!!
made a believer out of me and the owner.
My PN# RME87-3C9992 hope this helps
Not to dig up this thread from the dead, but we're having the same problem on my buddy Zach's truck. It consistently did it in the top of second gear recently and we're going to do some troubleshooting with is this weekend. We have a couple spare 87mm TB's to test out and see if it fixes the problem. I'll report back with part numbers of the TB's that work.
'20 AT4
'01 Suburban 2500 Dad Wagon
If it's running ok otherwise, the TB sensor reads all the way to 100% and its just doing it at the top of 2nd it could be that the Calc Airflow table and/or MAF Cylair Max tables needs to be increased.
If that has been taken care of a new truck TB took care of all of my problems. It idles better and the TB sensor reads all the way to 100% now. Mine is still working perfectly!
Yeah it definitely doesn't read 100% consistently, last night at the track it would max out at 98%. I noticed in a few logs when I first retuned it after the 370/L92 swap the TPS would drop a percent or three randomly in the logs at WOT.
I told him to swap out the TB's he has and see if it fixes the problem. Gonna try that this afternoon and see if the TPS will read 100
'20 AT4
'01 Suburban 2500 Dad Wagon
Did this solve his problems?
What were the part numbers?
The new LS3/7 throttle body part number is 12605109, it's a ported looking design and opens really fast. Works on 07-11 vehicles too. Some have had weird issues on vettes, but I've put them on trucks without issues.
'20 AT4
'01 Suburban 2500 Dad Wagon
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