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idle surging from timing glitch - HPT

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Old Feb 1, 2016 | 11:29 AM
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Default idle surging from timing glitch - HPT

been working on this pain in the *** idle surge. Its apparently caused by this timing glitch that drops to 1 to 2 degrees when I have all the maps intentionally set to 15 degrees to try and narrow down the problem. I even changed the high and low octane maps to 15 just to cover all bases. I even zero'd the over and under speed maps to zero and its still the same. any help would be really appreciated. gen 3 6.0 engine with manual set trans. not sure if its related but the engine also hits a wall at 3k rpm only in drive and bounces like its hitting a limiter of some sort.

here is a short log of what its doing along with my tune
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File Type: hpl
idle_timingdrop.hpl (2.1 KB, 69 views)
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Old Feb 1, 2016 | 01:01 PM
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I there a reason your throttle position sensor is showing 18%?

you're not in the idle tables if this is what the computer thinks you are running. You'll need to get your TPS reading 0% at idle before you can fix anything else.

the TPS volts aren't logged. do you know what voltage you have the TPS set to?
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Old Feb 1, 2016 | 09:18 PM
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Originally Posted by Darth_V8r
I there a reason your throttle position sensor is showing 18%?

you're not in the idle tables if this is what the computer thinks you are running. You'll need to get your TPS reading 0% at idle before you can fix anything else.

the TPS volts aren't logged. do you know what voltage you have the TPS set to?
the tps wont adjust down that low. would this even be an issue whether its on idle map or not. that still doesn't answer why is the timing jumping around like that? ill check tomarro and see what the tps voltage is.
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Old Feb 2, 2016 | 01:36 PM
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Your engine should be DBW, and won't see 0% TPS.

Russ Kemp
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Old Feb 2, 2016 | 09:12 PM
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Originally Posted by Russ K
Your engine should be DBW, and won't see 0% TPS. Russ Kemp
my bad. I saw gen 3 in the OP and assumed cable throttle. Thanks for correcting.
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Old Feb 2, 2016 | 11:34 PM
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Originally Posted by Russ K
Your engine should be DBW, and won't see 0% TPS.

Russ Kemp
No it's not.
Attached Thumbnails idle surging from timing glitch - HPT-no-its-not.jpg  
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Old Feb 3, 2016 | 11:34 AM
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fixed it. zero'd the idle area of the base retard in the knock retard attack section. I think it may have been picking up alittle noise from the piston slap from having forged pistons.
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Old Feb 3, 2016 | 02:53 PM
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So does your truck have a throttle cable or is it DBW?

Russ Kemp
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