LBZ: Turbo cycling/fluxuating at idle

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lotsofmiles

Father of the Van
Dec 4, 2008
3,097
0
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Michigan
This just started happening last night -

Stopped at a light with my foot on the brake and the turbo is building boost, going from 0 psi up to 2.x psi randomly. sometimes i can hear the vanes close and rapidly reopen. doesnt seem to change idle rpms any.

and the boost is going up and back down fast enough it isnt registering a change on the 6gun moniter (the boost stays on 0 while stopped), but if I look at the Snow meth controller it does show the boost change.

nothing has changed on the truck/tune in a while. and this just started last night.

only thing I did do before this trip was cleaned/oiled the filter. But that was - wash the filter, let it dry for 8 hours, oil it, let it sit an hour, wipe any excess oil, installed and let truck sit for 14 hours before starting.

ran the truck from Michigan to Alabama and back Fri/Sat and it was normal all the way there and almost back. just started doing it when i got off the highway a couple hours from home and still doing it when i sat in the driveway.

any thoughts?

sensor going bad?

need to get twins?:joker::angel:D

I'LL log it andpost it later today

thanks:hug:
 
DmaxHawk

DmaxHawk

Ranch with my Salad
Oct 28, 2008
699
0
16
the 575
Definitely sounds like a case of turbo depression, you need to get twins immediately to relieve loneliness :angel:


My guess would be sensor is going bad. Were you building 2.X at idle? I cant get that with my vanes at 99. Do have a mechanical gauge? Could be the snow monitor is not showing actual?:dontknow: Sounds like boost changes too fast for it being at idle
 
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lotsofmiles

Father of the Van
Dec 4, 2008
3,097
0
0
Michigan
the snow gauge is a tube tapped into the intake manifold right where the injectors are. and yea its getting up to 2.x psi without pressing the go pedal
 
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lotsofmiles

Father of the Van
Dec 4, 2008
3,097
0
0
Michigan
ok, here is a short log of it.

the boost was going up and down from 0-1.6, up and down, up and down....

only showing on the snow controller, and like i said when it was doing it earlier i could hear the vanes opening and closing.

earlier it was going up to 2psi
 
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lotsofmiles

Father of the Van
Dec 4, 2008
3,097
0
0
Michigan
LBZrcks said:
Maybe try to relearn the position? or the sensor might be failing
Click to expand...

its trying to relearn or i need to make it relearn?


just for giggles i was going to reload the stock tune and run the 6gun for tommorrow, but i cant get the new laptop to load the drivers for efi, uggggg.
 
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LBZrcks

.........
Jun 2, 2007
5,297
12
38
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SoCal
lotsofmiles said:
its trying to relearn or i need to make it relearn?


just for giggles i was going to reload the stock tune and run the 6gun for tommorrow, but i cant get the new laptop to load the drivers for efi, uggggg.
Click to expand...

I know a tech 2 can do it, but not sure if EFI can do it with the dvt's. I did see an option for vnt offset learn, not sure if it;s the same thing a tech 2 does.
 
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lotsofmiles

Father of the Van
Dec 4, 2008
3,097
0
0
Michigan
ok i'll clean it. thanks.


i know its going up and down. noticed today when it goes above 2 psi the exhaust hisses then it comes back down
 
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lotsofmiles

Father of the Van
Dec 4, 2008
3,097
0
0
Michigan
i'll have to try to log it again. the log i did the boost was only going up to 1.6-1.7.
sometimes it was hitting 2.2-2.3 and i was hearing the vanes changing too
 
Killerbee

Killerbee

Got Honey?
Aug 28, 2007
976
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Phoenix, AZ-Low enthalpy air!
members.cox.net
Occasional vane cycling is 100% normal diagnostics.

I am telling ya, if you only have idle fueling, under 800 rpm, there is no way in hell you are making 2 psi, over ambient, of boost.

If meth is getting in, maybe that is an issue, but still don't think so.
 
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