PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

need help trouble shooting an issue

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Old Sep 10, 2018 | 07:48 AM
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hi,

i have a issue my car would run rich on open loop , on closed loop it would have +15 fuel trim but idles better and wot is really rich, the issue is not tune related, no matter how much i change the ve table its still not getting better
i thought it might be exhaust leak which i tried to fix multiple times but since i still have the same issue at open loop from my understanding open loop doesnt effect the o2 so there shouldnt be any issue unless small leaks would effect backpressure,

how my question is what do i look for to diagnose the issue, its ls2 engine on 0411 running speed density
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Old Sep 10, 2018 | 09:17 AM
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Originally Posted by QTR FMS
hi,

i have a issue my car would run rich on open loop , on closed loop it would have +15 fuel trim but idles better and wot is really rich, the issue is not tune related, no matter how much i change the ve table its still not getting better
i thought it might be exhaust leak which i tried to fix multiple times but since i still have the same issue at open loop from my understanding open loop doesnt effect the o2 so there shouldnt be any issue unless small leaks would effect backpressure,

how my question is what do i look for to diagnose the issue, its ls2 engine on 0411 running speed density
What injectors? This is just a stock ls2?
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Old Sep 10, 2018 | 03:21 PM
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Originally Posted by TPIZ92
What injectors? This is just a stock ls2?
yeah stock ls2 injector, the car is tuned for cam, nothing changed on the car or tune, the only thing i did is i removed the passenger headers to fix the signal wire on the starter and put it back together and the catback was slightly modified to raise it few inches but thats it cant think of any other thing that would cause any issue,checked fuel pressure its good, i took the car to couple of muffler shops to find a leak but there is none
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Old Sep 10, 2018 | 04:10 PM
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whats that banks' narrowband oscillation like? are the o2's on that car case grounded or grounded though the harness?
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Old Sep 10, 2018 | 04:34 PM
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Originally Posted by truckdoug
whats that banks' narrowband oscillation like? are the o2's on that car case grounded or grounded though the harness?
its psi harness 1055 with square 4 wire gm o2
this is the data log i made on from the untouched tune file from my tuner


Attached Files
File Type: hpl
idle.hpl (112.5 KB, 33 views)
File Type: hpl
test 1.hpl (409.2 KB, 19 views)
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Old Sep 10, 2018 | 07:18 PM
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in those two idle logs i couldnt see any smoking gun. AFR is on point, STFTs are even bank to bank, injector pw is balanced bank to bank

the timing is jumping around like a MF tho. I'd probably take some idle spark over/under out and turn the idle down a little. but then it won't lope as hard


post up a cruise log where the trims are getting all wacky
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Old Sep 10, 2018 | 08:03 PM
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Originally Posted by truckdoug
in those two idle logs i couldnt see any smoking gun. AFR is on point, STFTs are even bank to bank, injector pw is balanced bank to bank

the timing is jumping around like a MF tho. I'd probably take some idle spark over/under out and turn the idle down a little. but then it won't lope as hard


post up a cruise log where the trims are getting all wacky
those are all the datalog i have, cant make more cause my one week old mpvi2 died,
what i did is i copied the data from each datalog and multiple by % from test 1 to ve6 and it didnt get better or worse, if i run openloop with short fuel trim i cant drive over idk 30-40 miles i tried to get to high way speed but the car keeps leaning out dies i caused a huge traffic jam i forgot to save that datalog,
on test 1 datalog seems good but the drivability and wot afr was awful if i waited the fuel trim would have went over 10%








Attached Files
File Type: hpl
ve6sft.hpl (396.0 KB, 27 views)
File Type: hpl
ve2.hpl (263.8 KB, 14 views)
File Type: hpl
ve4.hpl (798.3 KB, 23 views)
File Type: hpl
ve5sft.hpl (704.3 KB, 18 views)
File Type: hpl
ve1.hpl (880.5 KB, 18 views)
File Type: hpl
ve5.hpl (482.0 KB, 21 views)
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Old Sep 10, 2018 | 08:37 PM
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ok lemme peep those and get back to you
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Old Sep 11, 2018 | 04:38 PM
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when you get your interface back, add your map sensor in kPa into your channels and take another cruise log. hard to tell whats going on without knowing engine load
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Old Sep 11, 2018 | 04:57 PM
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Originally Posted by truckdoug
when you get your interface back, add your map sensor in kPa into your channels and take another cruise log. hard to tell whats going on without knowing engine load

i got the mpvi2 to work but now i have unlicensed vehicle error,
check those files they should get the map to read, i think the map is working fine cant see anything wrong

thanks
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File Type: xml
final.Layout.xml (18.9 KB, 23 views)
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