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Discussion Starter #1 (Edited)
Hey Guys,
I'm having an issue that seems to be alluding me and my tuner. We have tried several different things with the LS2 edit to no avail. So I'm turning here for ideas.

OK a brief history and my thoughts on it. I installed the HPE C cam and HPE ET 5.3 Heads and drilled the TB 7/32. The first trip to the tuner everything seemed to be great it Dyno'ed well and ran great. Then a few days later I was getting thrown into safe mode 2 codes 0068 & 0101. The 101 was the culprit we adjusted the MAF calculations and that fixed the code issue. Now I'm having a Idle surge issue when I decelerate it dips really low and stalls often. We slowed the throttle blade closure speed and that seemed to help at first but it starting to surge again.

I already decided I'm pulling the aluminum flywheel out this week I'm tired of having to slip the clutch so much just to get going. I'm thinking this may also help the idle smooth out a little. So go ahead and throw it at me I'm open for suggestions.:comp:
 

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THE ROKET WAS SOLD ON 6/22/14
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Did you drill the hole in the TB? I've heard that this will help with the idle and stalling problems on the LS2's. I'm sure you'll get more than enough replies soon enough. Try doing a search on it, it's been discussed a bunch of times. Good Luck.....

ROK
 

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Discussion Starter #3
ROKS ROCKET said:
Did you drill the hole in the TB? I've heard that this will help with the idle and stalling problems on the LS2's. I'm sure you'll get more than enough replies soon enough. Try doing a search on it, it's been discussed a bunch of times. Good Luck.....

ROK
Yes, I drilled the TB the recommended size (7/32) as per HPE. I know the high surging idle has been discussed many times but I'm having low idle dipping to the point it stalls sometimes.
 

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its seems only a few can tune a HPE cam right. so either find a better tuner, or chase it around it some more
 

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Discussion Starter #5
Jbss71 said:
its seems only a few can tune a HPE cam right. so either find a better tuner, or chase it around it some more
Thank you for you informative advise. But I was looking for something a little more helpful. Hopefully one of our tuning gurus or sponsors will chime in with some useful input.
 

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i'd send ya my tune but i use hptuners. i was told that ls2edit dosent have as many idle tables a HPtuners. true or not i dunno
 

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ls2 does not have the base airflow table, which is why they have to drill throttle bodies. One of the other things you can do is add more timing to the base timing table *below* your set idle, and add more timing to the Idle Adaptive Underspeed table. This helped me out quite a bit.
 

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^^^^ +1 Same here. After the Fast and Ported TB, I had idle problems where I would come to a light and it would drop to 200rpms, then bounce back up. Sometimes it wouldnt bounce back up, and WHAM stalled. We fixed it by changing the timinging in the lower RPM tables. Stock from factory the timing is 12 degrees. So we boosted that to 22 degrees and now I"m not having any problems. By getting so much air it was stalling me out. I didnt want to drill my TB so I found another solution. SO far so good.
 

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Discussion Starter #9
Thanks for the input I'll run these ideas by the tuner and see if has done anything in that area. Steel Chicken a pleasure as always and Flash thank you also. If you guys have anymore thoughts please feel free to post them.
Cheers
 

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Sure glad to be of help. Just have your tuner look at the stock timing tables, and think about whats happening.

Lets say you got your cammed motor idling at 1000rpm. If it starts to drop a little bit for whatever reason, the PCM is going to start using the lower rpms timing value, which is usually lower. Especially if you added idle timing because of a cam swap. So, your rpms are slowing down, and the PCM wants to pull even more timing. This makes it slow down even more, making it worse. Its a wrongway feedback loop.

I added like 2-3 degrees at 800 and 5-6 more at 600 to reverse this effect. It really did help. Its too bad the LS2s dont have the BAF table, because getting that table right is critical to LS1 cammed motors running right. Timing will help though.

The other thing he needs to do is make sure the idle timing tables and the main idle tables are not too far off each other, or every time the PCM switches from throttle conditions to idle conditions it can make a huge jump in timing, causing more instability.

The more a motor is cammed, the more of an effect timing becomes critical at idle/near idle conditions.
 
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