reduced engine power - early boosting?
Thread Starter
Drifting
Joined: Jun 2008
Posts: 1,778
Likes: 3
From: PNW
reduced engine power - early boosting?
Friends car
Set-up is a MN6 LS2 + M112 @ 9-10 PSI of boost. Engine is also cammed, otherwise stock.
Stock fuel system, 60lbs injectors.
The car was always fine, the last change involved moving from catless 1 3/4 to catless 1 7/8 primaries including a 3inch x-pipe + changing the CAI from a vararam to a callaway honker.
its worth mentioning that the crankcase evac hose that connects to the intake isnt installed, HOWEVER there is absolultey no way that could cause the problem
Problem appears under full throttle, check engine light comes on, reduced engine power, and the car disengages the throttle, applies the briefly applies the brakes, when the car comes to a stop, it vibrates like anything.
Turning off the vehicle for a minute solves the problem, just for it to re-appear again after another WOT run.
Reading the code says "Reduced engine power - Early Boosting"
any ideas?
I never knew an M112 can boost an LS2 up to 10PSI
Set-up is a MN6 LS2 + M112 @ 9-10 PSI of boost. Engine is also cammed, otherwise stock.
Stock fuel system, 60lbs injectors.
The car was always fine, the last change involved moving from catless 1 3/4 to catless 1 7/8 primaries including a 3inch x-pipe + changing the CAI from a vararam to a callaway honker.
its worth mentioning that the crankcase evac hose that connects to the intake isnt installed, HOWEVER there is absolultey no way that could cause the problem
Problem appears under full throttle, check engine light comes on, reduced engine power, and the car disengages the throttle, applies the briefly applies the brakes, when the car comes to a stop, it vibrates like anything.
Turning off the vehicle for a minute solves the problem, just for it to re-appear again after another WOT run.
Reading the code says "Reduced engine power - Early Boosting"
any ideas?
I never knew an M112 can boost an LS2 up to 10PSI
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
10 PSI is quite high for a MP112, are you sure that your gauge is correct or if it was calibrated. Many off the shelf AutoZone special and I have even seen Autometer manual type boost gauges that were way off. Most of the time their electronic gauges seems to be much more accurate.
As for your issue of getting a CEL lamp and reduced engine power have you checked to see what DTC is stored. I would bet that its air flow issue where the PCM is seeing too much air so it errors out thinking that there is a throttle body issue.
Check your engine cal. If you are using Hp Tuners you can check the Engine Diagnostics, then click on General tab, make sure that the airflow vs RPM table has been changed from stock, also Min ECT constant to enable the tests for P101, P106, and P121 has been raised so that the PCM doesn't perform the test. Those tests are for throttle body performance tests. If it sees high MAP, Air flow errors etc, it thinks that the ETC throttle has wacked out and will cut the throttle control. If y ou are using a canned tune from Callaway or Magnusson these parameters should have been changed already.
As for your issue of getting a CEL lamp and reduced engine power have you checked to see what DTC is stored. I would bet that its air flow issue where the PCM is seeing too much air so it errors out thinking that there is a throttle body issue.
Check your engine cal. If you are using Hp Tuners you can check the Engine Diagnostics, then click on General tab, make sure that the airflow vs RPM table has been changed from stock, also Min ECT constant to enable the tests for P101, P106, and P121 has been raised so that the PCM doesn't perform the test. Those tests are for throttle body performance tests. If it sees high MAP, Air flow errors etc, it thinks that the ETC throttle has wacked out and will cut the throttle control. If y ou are using a canned tune from Callaway or Magnusson these parameters should have been changed already.
Thread Starter
Drifting
Joined: Jun 2008
Posts: 1,778
Likes: 3
From: PNW
10 PSI is quite high for a MP112, are you sure that your gauge is correct or if it was calibrated. Many off the shelf AutoZone special and I have even seen Autometer manual type boost gauges that were way off. Most of the time their electronic gauges seems to be much more accurate.
As for your issue of getting a CEL lamp and reduced engine power have you checked to see what DTC is stored. I would bet that its air flow issue where the PCM is seeing too much air so it errors out thinking that there is a throttle body issue.
Check your engine cal. If you are using Hp Tuners you can check the Engine Diagnostics, then click on General tab, make sure that the airflow vs RPM table has been changed from stock, also Min ECT constant to enable the tests for P101, P106, and P121 has been raised so that the PCM doesn't perform the test. Those tests are for throttle body performance tests. If it sees high MAP, Air flow errors etc, it thinks that the ETC throttle has wacked out and will cut the throttle control. If y ou are using a canned tune from Callaway or Magnusson these parameters should have been changed already.
As for your issue of getting a CEL lamp and reduced engine power have you checked to see what DTC is stored. I would bet that its air flow issue where the PCM is seeing too much air so it errors out thinking that there is a throttle body issue.
Check your engine cal. If you are using Hp Tuners you can check the Engine Diagnostics, then click on General tab, make sure that the airflow vs RPM table has been changed from stock, also Min ECT constant to enable the tests for P101, P106, and P121 has been raised so that the PCM doesn't perform the test. Those tests are for throttle body performance tests. If it sees high MAP, Air flow errors etc, it thinks that the ETC throttle has wacked out and will cut the throttle control. If y ou are using a canned tune from Callaway or Magnusson these parameters should have been changed already.
It was a canned tune from LPE, and the car ran fine before the header, CAI and x-pipe swap. No idea how would such things cause this problem.
Again, when we face the problem, the car idles VERY roughly and vibrated all over the place, which is weird
but well check the parameters you suggested.Anyone else?
Safety Car
Joined: Oct 2001
Posts: 4,945
Likes: 0
From: Dallas/Valley Ranch TEXAS!!!
p.s, Shawn, if you search through Threads by me (Mr.Big) using the "search" feature I've written a BUNCH of threads pertaining to this... If more help is needed go back and read through those posts, you will find your answers and then some...
Thread Starter
Drifting
Joined: Jun 2008
Posts: 1,778
Likes: 3
From: PNW
Melting Slicks
Joined: Feb 2006
Posts: 2,184
Likes: 2
Friends car
Set-up is a MN6 LS2 + M112 @ 9-10 PSI of boost. Engine is also cammed, otherwise stock.
Stock fuel system, 60lbs injectors.
The car was always fine, the last change involved moving from catless 1 3/4 to catless 1 7/8 primaries including a 3inch x-pipe + changing the CAI from a vararam to a callaway honker.
its worth mentioning that the crankcase evac hose that connects to the intake isnt installed, HOWEVER there is absolultey no way that could cause the problem
Problem appears under full throttle, check engine light comes on, reduced engine power, and the car disengages the throttle, applies the briefly applies the brakes, when the car comes to a stop, it vibrates like anything.
Turning off the vehicle for a minute solves the problem, just for it to re-appear again after another WOT run.
Reading the code says "Reduced engine power - Early Boosting"
any ideas?
I never knew an M112 can boost an LS2 up to 10PSI
Set-up is a MN6 LS2 + M112 @ 9-10 PSI of boost. Engine is also cammed, otherwise stock.
Stock fuel system, 60lbs injectors.
The car was always fine, the last change involved moving from catless 1 3/4 to catless 1 7/8 primaries including a 3inch x-pipe + changing the CAI from a vararam to a callaway honker.
its worth mentioning that the crankcase evac hose that connects to the intake isnt installed, HOWEVER there is absolultey no way that could cause the problem
Problem appears under full throttle, check engine light comes on, reduced engine power, and the car disengages the throttle, applies the briefly applies the brakes, when the car comes to a stop, it vibrates like anything.
Turning off the vehicle for a minute solves the problem, just for it to re-appear again after another WOT run.
Reading the code says "Reduced engine power - Early Boosting"
any ideas?
I never knew an M112 can boost an LS2 up to 10PSI
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