08-27-2019, 09:39 PM | #1 |
Drives: 2018 Chevrolet Camaro 2SS 1LE 6M Join Date: Jul 2019
Location: California
Posts: 283
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PCM pulling timing at 6k rpm
Having an interesting issue with my 2018 Camaro SS 1LE. Had the car tuned a couple of weeks ago and I have been sorting out a few issues. The part throttle was a little wonky and playing with the throttle tables smoothed out that problem. I am seeing a strange problem at full throttle. The PCM is pulling 10-15 degrees at around 6,000 RPM at full throttle. It's not knock retard. No matter if I am running 21 degrees or 25 degrees, the same thing occurs. The only mods on the car are a Soler Performance throttle body, a Green filter drop in air filter, and a flex fuel kit. The E85 that I am getting at the local pumps runs about 78-80% ethanol. I have attached a screen shot of the datalog right before the problem occurs, and one of the actual issue occurring. Ideas?
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08-29-2019, 01:00 AM | #2 |
Drives: 6th gen Join Date: Aug 2013
Location: US
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Are you logging all the torque pids?
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08-29-2019, 09:05 AM | #3 |
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Drives: 2012 2SS CAMARO 45th Join Date: Apr 2011
Location: St. Charles, IL
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That's a torque table issue. It'll pull timing if your max torque is over peak torque or if you eng torque is over max torque. It's not very fun to work with but I'd take it back to your tuner. They most likely didn't dial in your VE tables
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08-29-2019, 12:26 PM | #4 |
Drives: 2018 Chevrolet Camaro 2SS 1LE 6M Join Date: Jul 2019
Location: California
Posts: 283
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Thanks for the input. The torque limits were moved up by 25%. Not sure which torque PIDs would be helpful in diagnosing this issue. Could you be more specific?
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09-09-2019, 12:43 AM | #5 |
Drives: 2018 Chevrolet Camaro 2SS 1LE 6M Join Date: Jul 2019
Location: California
Posts: 283
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I finally figured it out. For some reason the PCM is seeing more than the estimated max value for the MAP sensor. Upping the value eliminated the problem.
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09-11-2019, 03:24 PM | #6 |
Drives: 2016 1SS NFG A8 Join Date: Aug 2017
Location: 46804
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you shouldn't be over 100 unless you are running boost.
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Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA |
09-12-2019, 12:05 AM | #7 |
Drives: 2018 Chevrolet Camaro 2SS 1LE 6M Join Date: Jul 2019
Location: California
Posts: 283
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The stock value for estimated MAP maximum is 105 kPa. Datalogs show that the maximum logged MAP value is 100 kPa. Not sure why the PCM is reacting to the MAP value the way it is, but moving the estimated MAP maximum up to 135 kPa eliminated the issue. I have attached a screen shot of a datalog I just pulled tonight, with a nice straight timing curve-no timing being pulled at 6k RPM.
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09-28-2019, 08:15 PM | #8 |
Drives: Chevrolet Camaro 2SS Join Date: Jul 2019
Location: FL
Posts: 139
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this is pretty interesting. I would like to hear more about what the values should be and how/why you are maxing out if you are n/a?
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09-30-2019, 08:47 AM | #9 |
Drives: 17 Camaro SS 1LE & 16 Sierra AT CC Join Date: Nov 2016
Location: Norman, OK
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To really be able to see what is pulling any timing you need to log all of the timing systems so you can see what is pulling the timing.
Torque management timing Timing advance PE timing KR timing Flex timing Coolant timing IAT timing I think there is something like 5-8 timing PIDs that need to be logged so you can see what is pulling the timing. Glad you found, hope that helps out for the future logs.
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10-30-2019, 02:20 PM | #10 | |
@texan.1le
Drives: '18 Camaro 1SS 1LE, PDR Join Date: Jun 2018
Location: Temple, TX
Posts: 182
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Quote:
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'18 1SS 1LE - "Mongoose"
'15 Malibu 2LT - daily |
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11-08-2019, 07:14 AM | #11 |
@texan.1le
Drives: '18 Camaro 1SS 1LE, PDR Join Date: Jun 2018
Location: Temple, TX
Posts: 182
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Bump.
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'18 1SS 1LE - "Mongoose"
'15 Malibu 2LT - daily |
11-08-2019, 07:19 AM | #12 |
Drives: Chevrolet Camaro 2SS Join Date: Jul 2019
Location: FL
Posts: 139
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Zero out your Static knock table.
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11-08-2019, 07:45 AM | #13 |
Drives: 18 Camaro LS M6 Join Date: Apr 2019
Location: NH
Posts: 698
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If your graphing, check the HZ peak, and look up in the limit table, 13300hz maybe? It may be MAF HighVoltage Fail. Its a suggested remedy for boosted tuning limits. I don't have the path in front of me but should be easy to located under Air menu. HPT.
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11-12-2019, 08:15 AM | #14 |
Drives: 1999 Trans Am Join Date: Jul 2009
Location: Bridgewater,Ma
Posts: 2,017
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I see your not logging actual torque 1+2. Those will show torque drop in that area.
Going to the torque model tables and adjusting airflow would get rid of it too. |
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