RTT doesn't match tune
Feb 20, 2007 | 09:14 PM
#1
Thread Starter
Joined: Nov 2004
Posts: 27,563
Likes: 3
From: Maryland
RTT doesn't match tune
This **** is driving me crazy. truck runs like ***.
RTT with scanner...
Tune presently in PCM...
WTF?!?!!? Look at idle region. I have done a full write twice now.I actually have notta a clue how long it's been like this. I have been quiet frustrated with dialing the ve in and then all of a sudden it goes rich again. Lean the next week. I do upload tunes alot. I like screwing with crap, so you can factor i could have messed something up myself...BUT WHAT?!!??!
RTT with scanner...
Tune presently in PCM...
WTF?!?!!? Look at idle region. I have done a full write twice now.I actually have notta a clue how long it's been like this. I have been quiet frustrated with dialing the ve in and then all of a sudden it goes rich again. Lean the next week. I do upload tunes alot. I like screwing with crap, so you can factor i could have messed something up myself...BUT WHAT?!!??!
Last edited by dewmanshu; Feb 20, 2007 at 09:32 PM.
Feb 20, 2007 | 09:34 PM
#3
Thread Starter
Joined: Nov 2004
Posts: 27,563
Likes: 3
From: Maryland
Originally Posted by CurtD
Oh hell, Thats why i haven't messed with my RR yet i know it will drive me crazy...and it will be a short trip 
freaking frackin piece of phookin ...dammmmmmiiiiiit!!!!
Feb 20, 2007 | 09:47 PM
#5
Neither of these look all that realistic to me. I don't see
how pressure / gas density can be swinging VE almost
2:1 and in places where the flow ought not to be too
challenged by the plumbing.
What is your feedback for the RTT and do you trust it?
What other errors in the system, might VE RTT be trying
to deal with (on an inappropriate basis)? Anything other
than true airflow, being inappropriate elements of the VE
result.
You have to remain suspicious of wideband meters, they
only report what they're given and the output can be so
easily bent. Some of them, just the grounding scheme is
a large source of error, the heater current modifies ground
current & ground offset so even the weather (by its
effect on the sensor heat loss and heater makeup power)
can affect results - even if the meter itself reports true,
the voltage difference received at the tuning "pod" can
be variably messed around. So too, other accessories
injecting return currents to the chassis can jack things.
You have to satisfy yourself about the accuracy and the
consistency of the instrument. And realize that what you
see at idle closed loop may not be the same heater power
situation as WOT, variable output gain errors as well as
baseline offsets, all these things I have seen reported.
Lucky for me, the Innovate LogWorks software update
pretty well fvcked my comms so I just read the digital
display on the LM-1... no ground problems here. Heh.
You might try a third vote, which would be to put EQ
to 1.000 everywhere, drive & log open loop, bump VE
by hand by the NBO2 voltages until you get everything
staying 400-600mV on your histogram. You can cover
much of the space like that although not the higher MAP
without pulling mucho timing and this also affects the
accuracy some. But what you get out of the exercise
will be pretty trustworthy, it uses a pretty plain device
in its region of greatest fidelity and no funny stuff other
than maybe a little short on exhaust heat at low flows.
how pressure / gas density can be swinging VE almost
2:1 and in places where the flow ought not to be too
challenged by the plumbing.
What is your feedback for the RTT and do you trust it?
What other errors in the system, might VE RTT be trying
to deal with (on an inappropriate basis)? Anything other
than true airflow, being inappropriate elements of the VE
result.
You have to remain suspicious of wideband meters, they
only report what they're given and the output can be so
easily bent. Some of them, just the grounding scheme is
a large source of error, the heater current modifies ground
current & ground offset so even the weather (by its
effect on the sensor heat loss and heater makeup power)
can affect results - even if the meter itself reports true,
the voltage difference received at the tuning "pod" can
be variably messed around. So too, other accessories
injecting return currents to the chassis can jack things.
You have to satisfy yourself about the accuracy and the
consistency of the instrument. And realize that what you
see at idle closed loop may not be the same heater power
situation as WOT, variable output gain errors as well as
baseline offsets, all these things I have seen reported.
Lucky for me, the Innovate LogWorks software update
pretty well fvcked my comms so I just read the digital
display on the LM-1... no ground problems here. Heh.
You might try a third vote, which would be to put EQ
to 1.000 everywhere, drive & log open loop, bump VE
by hand by the NBO2 voltages until you get everything
staying 400-600mV on your histogram. You can cover
much of the space like that although not the higher MAP
without pulling mucho timing and this also affects the
accuracy some. But what you get out of the exercise
will be pretty trustworthy, it uses a pretty plain device
in its region of greatest fidelity and no funny stuff other
than maybe a little short on exhaust heat at low flows.
Feb 20, 2007 | 10:12 PM
#6
Thread Starter
Joined: Nov 2004
Posts: 27,563
Likes: 3
From: Maryland
First...thanks foff for the fast response. Downloaded the beta and I'll give her a run tomorrow.
Jimmy, you must stay in the truck section more often. I don't frequent tech much anymore and...sadly...I only hit hpt when i am in trouble, I actually miss your THOROUGH explanations on stuff.
I have a dynojet WB. I just...I mean JUST replaced the sensor. I actually hard wired my sensor. I bought the sensor from volkswagon (online parts store) and soldered her in place. Grounds are golden.
I am 2bar, SD, OL. My nbo2's are not an option at this time to use as "guides". One is shot and both have crummy connections (corrosion-truck has seen better days) Sooooooo, with all that said, I am kinda forced to trust my WB at this time. HOWEVER a spark plug inspection last night showed some lean conditions, but WB is showing rich conditions. SO, I am in the process of re-doing my exhaust sensor setup to accomodate my investigation of these issues.
I am actually suffering from what I believe a converter not cooperating and causing horrible lugging issues as well. (I believe your expert area there). Too many problems all at once. I have alot to report once i get everything fixed....some day. I even dissected my freaking steroe and did a soldering repair on it. At 130K miles with 50K on the blower, I should expect issues huh. Just trying to get a handle on all of this AND making changes to a RTT that is 6 to 9% higher than my actual tune ve is really a kick in the nuts when you copy and paste the RTT VE to your tune.
Jimmy, you must stay in the truck section more often. I don't frequent tech much anymore and...sadly...I only hit hpt when i am in trouble, I actually miss your THOROUGH explanations on stuff.
I have a dynojet WB. I just...I mean JUST replaced the sensor. I actually hard wired my sensor. I bought the sensor from volkswagon (online parts store) and soldered her in place. Grounds are golden.
I am 2bar, SD, OL. My nbo2's are not an option at this time to use as "guides". One is shot and both have crummy connections (corrosion-truck has seen better days) Sooooooo, with all that said, I am kinda forced to trust my WB at this time. HOWEVER a spark plug inspection last night showed some lean conditions, but WB is showing rich conditions. SO, I am in the process of re-doing my exhaust sensor setup to accomodate my investigation of these issues.
I am actually suffering from what I believe a converter not cooperating and causing horrible lugging issues as well. (I believe your expert area there). Too many problems all at once. I have alot to report once i get everything fixed....some day. I even dissected my freaking steroe and did a soldering repair on it. At 130K miles with 50K on the blower, I should expect issues huh. Just trying to get a handle on all of this AND making changes to a RTT that is 6 to 9% higher than my actual tune ve is really a kick in the nuts when you copy and paste the RTT VE to your tune.
Thread
Thread Starter
Forum
Replies
Last Post
ZO6Ted
GMT K2xx Trucks General Discussion
9
Aug 12, 2015 07:50 PM
