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RPM keeps climbing with no throttle?

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ForYourOwnGood

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Actually, I’d maybe shoot @EBtech a message and ask if it could possibly be the bypass valve. The revs increase because the load to push the car is gone (clutch in) but the throttle body is still open or the bypass valve is stuck and allowing boost still. I’d look at those 2 things mechanically.

Did you move or play with the bypass valve during install? Warning sticker on it not to move it...
No I was careful not to move it at all. I know better than to damage those diaphragms.

Three questions, is this an OE throttle body, do you have a catch can setup of some sort, and do you have long tube headers?

Something isn't playing nice with the OE rev hang programming which of course is an emissions strategy. It might be reliant on the MAP sensor seeing manifold vacuum before closing the throttle, which it won't see under boost until the throttle is actually closed or some other parameters are met.

I'd start by smoke testing for a vacuum or intake leak and go from there.
OEM throttle body, yes catch can and no long tubes. I have a tune revision that disables the rev hang I just haven't had a chance to get it flashed yet. This effect only happens some of the time so its really hard to pin down. I have checked for vacuum leaks and had it smoked, my buddy has one of the smoke generators and plug kits. I'm also not getting any symptoms of unmetered air in the system at all.
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aleccesarenriquez

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DId you ever figure out the issue? I'm having this exact same issue right now. Log looks identical

upload_2020-5-25_3-6-57.png
 

aleccesarenriquez

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Can you log throttle plate position also?
Do you know what that pid might be called? Don't really see any mention of a throttle plate position in the ones I have listed.
 

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aleccesarenriquez

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I think they're called Throttle Angle and Throttle Angle Desired (?)
Doesn't look like Lund included those pids in their config file. Be interesting to see if the throttle body is actually getting stuck open like that.
 

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Doesn't look like Lund included those pids in their config file. Be interesting to see if the throttle body is actually getting stuck open like that.
Here’s one of my logs from a Lund tune. Note the selected PIDS (rpm, pedal and throttle blade).
Here’s the thing:
I distinctly remember this particular log and how I had to pedal it a bit at the top of third gear.
You can see me dancing on the throttle to straighten the car up, but according to the log, the throttle blade remained wide open (it absolutely did NOT remain wide open).
I can’t explain what’s going on here.
120900D5-49FC-4FFD-8469-21FA91AD5EBD.png
 

Avispa

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Faulty throttle position sensor maybe. Its the only way the PCM knows where the throttle really is. An intermittent sensor might not throw an error code.

You'd think after 15 years with electric throttles thus kind of stuff wouldn't happen but....
 

aleccesarenriquez

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Here’s one of my logs from a Lund tune. Note the selected PIDS (rpm, pedal and throttle blade).
Here’s the thing:
I distinctly remember this particular log and how I had to pedal it a bit at the top of third gear.
You can see me dancing on the throttle to straighten the car up, but according to the log, the throttle blade remained wide open (it absolutely did NOT remain wide open).
I can’t explain what’s going on here.
120900D5-49FC-4FFD-8469-21FA91AD5EBD.png
Didn't know ETC_ACT was throttle angle. Here is that same log. Looks like throttle closes a little bit after I left off but for some reason rpm spikes to over 8100 anyways. Throttle angle seems to decrease too so it's not getting stuck open either.

Looking at your log shows an even more substantial throttle delay. Have you tried to resolve that or have you just made it an afterthought? I did notice your rpms fell accordingly when you did let off. Mine just sky-rocketed.

Lund did get back to me and said the behavior was normal. Not entirely convinced yet.

upload_2020-5-27_2-13-20.png
 

Burkey

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Didn't know ETC_ACT was throttle angle. Here is that same log. Looks like throttle closes a little bit after I left off but for some reason rpm spikes to over 8100 anyways. Throttle angle seems to decrease too so it's not getting stuck open either.

Looking at your log shows an even more substantial throttle delay. Have you tried to resolve that or have you just made it an afterthought? I did notice your rpms fell accordingly when you did let off. Mine just sky-rocketed.

Lund did get back to me and said the behavior was normal. Not entirely convinced yet.

upload_2020-5-27_2-13-20.png
That’s the weird part, there is NO delay in reality. Not sure why the log shows what it shows. I clearly remember having to get off/on the juice to straighten it up, along with the car doing as a I’ve asked (as you can see with the rpm change).
If you look at it carefully, you can see where the wheel spin started, my reaction on the pedal, rpm dropping cos it hooked again, me having another gentle stab at it and then giving up.
I’ve highlighted (in red) the bit where I’d say I’ve “called it” and the bit where the ETC_ACT decides to drop off. The time difference between those event is 0.12 seconds.
The interesting part to me is that the ETC_ACT doesn’t move at all until the pedal is at 3%.
I can’t explain any of it. The car drives just fine, no hang, nothing of the sort.
It’s as though the PID isn’t grabbing the data correctly for whatever reason.
BA264072-26AA-488D-865C-F75E602CBF6D.jpeg
 

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aleccesarenriquez

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That’s the weird part, there is NO delay in reality. Not sure why the log shows what it shows. I clearly remember having to get off/on the juice to straighten it up, along with the car doing as a I’ve asked (as you can see with the rpm change).
If you look at it carefully, you can see where the wheel spin started, my reaction on the pedal, rpm dropping cos it hooked again, me having another gentle stab at it and then giving up.
I’ve highlighted (in red) the bit where I’d say I’ve “called it” and the bit where the ETC_ACT decides to drop off. The time difference between those event is 0.12 seconds.
The interesting part to me is that the ETC_ACT doesn’t move at all until the pedal is at 3%.
I can’t explain any of it. The car drives just fine, no hang, nothing of the sort.
It’s as though the PID isn’t grabbing the data correctly for whatever reason.
Might be due to a slower sampling rate from the throttle sensor?

My issue is a little bit different though. Your rpm seems to respond fine to letting off, while mine wants to go to the moon.
 

aleccolin

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How are your BOVs plumbed? Are they venting to atmosphere? Where is the boost/vac reference coming from? You don't have a check valve in the boost reference line, do you?
 

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Might be due to a slower sampling rate from the throttle sensor?

My issue is a little bit different though. Your rpm seems to respond fine to letting off, while mine wants to go to the moon.
I think you’re dead-on. Even when the pedal goes WOT at the start, you can clearly see the lag in response of the etc PID. Seems that it’s not the most reliable source of data.
 

aleccesarenriquez

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How are your BOVs plumbed? Are they venting to atmosphere? Where is the boost/vac reference coming from? You don't have a check valve in the boost reference line, do you?
They are routed off the vacuum block, along with everything else. No check valves
 

Fouledout421

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Any update? Having a similar issue, but with a ProCharger and auto trans. After a 3/4 to wot pull, I'll let out but the power keeps coming.
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