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what to data log?

5K views 10 replies 3 participants last post by  Blazin TA  
#1 · (Edited)
have an 06 lbz. it started getting shitty fuel mileage about 3-4 weeks ago. changed the fuel filter and cleaned the air filter. mileage didnt change. truck used to get anywhere from 19-23mpg depending on what i was doing. would get around 15mpg pulling a 9k lb trailer. now the truck wont get over 16mpg running empty.

I have efi live. i have never data logged with it before. i am pretty sure i know how. just dont know what PIDS i need to choose to check. im thinking maybe its a bad injector or cp3 or somthin? any help would be appreciated.
 
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#3 · (Edited)
It should auto-select the first 15 PIDS to log, then after you log it and open the log file under Dashboard (B), you can view many PIDS at once (maybe 8 or so) and you can change the ones that it displays. Let me know if this helps.
 
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#4 · (Edited)
yes, that helps. im just not sure if the 15 PID's it selects are going to give me info on my cp3 and injectors which are the only things i can really think of that may be causing my bad fuel mileage.
 
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#5 · (Edited)
your CP3 info should already be selected (when viewing the log, look at desired rail pressure vs. your actual rail pressure. they shouldn't differ by more than a couple thousand at most throughout the RPM range).

For your injectors, you'll wanna select all eight balance rates PIDS and check them vs. factory specs. IIRC, they should be between +/- 4mm3 each @ idle in park. Outside that, and you may have a bad injector. Let me know how it turns out.
 
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#7 ·
Connect to your truck, open scan tool, at the top click the "info" drop down then click "validate pids" and see if the balance rates are supported then. Sometimes when I look up pids when i'm not connected to my truck it will say not supported but when I'm connected they work. Good luck.
 
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#9 ·
ok, so when i try and start datalogging i get an error. heres what it says


Error code: ERR_RESPONSE/5
Response $11: "Mode Not Supported".

theres a bunch of other **** after that. but thats the main thing. i updated to build 88. still wouldnt work.

any idea?
 
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#10 ·
Sorry, can't help with that. Hopefully cindy will see this, she will be able to help.
 
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#11 ·
ok, i got it. i think i was trying to log too many pid's.

so my injector balance rates at an idle were like this.

#1: 2.80
#2: 1.09
#3: -1.95
#4: -0.05
#5: -0.41
#6: -1.85
#7: -0.97
#8: -1.22

is this ok?

my rail pressure seemed to hold within 1500-2000 of desired. it would drop a few thousand during shifts put would pull back up.
 
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