Notices
Tuning, Diagnostics, Electronics, and Wiring HP Tuners | EFILive | Hand Held Programmers | Stand Alone PCM's | Electronics | Wiring Diagrams

the reduced engine power blues

Thread Tools
 
Search this Thread
 
Old 05-03-2012, 04:21 PM
  #1  
TECH Junkie
Thread Starter
iTrader: (9)
 
Gadgetized's Avatar
 
Join Date: Jan 2010
Location: Rochester, NY
Posts: 3,095
Likes: 0
Received 3 Likes on 3 Posts
Default the reduced engine power blues

Well I got my truck out yesterday for the spring. I went WOT, and it went into REP. I have an EFILive COS SD tune. I am not getting any codes, just REP mode. Does anyone know of a way to disable this.
Old 05-03-2012, 04:26 PM
  #2  
Custm2500's Rude Friend
iTrader: (17)
 
1FastBrick's Avatar
 
Join Date: Apr 2007
Location: JunkYard
Posts: 14,383
Received 786 Likes on 652 Posts
Default

The question is why did it go into REP mode... On an 05 I would think maybe you have the dreaded wiring issue that has plagued so many of the electronic throttle body trucks. I know there is a TSB on it. You should be getting some type of code setting in order for it to go into REP mode.

How are you checking for Codes??? EFI LIVE??? Are you looking for Pending as well as permanent codes???
Old 05-03-2012, 04:54 PM
  #3  
TECH Junkie
Thread Starter
iTrader: (9)
 
Gadgetized's Avatar
 
Join Date: Jan 2010
Location: Rochester, NY
Posts: 3,095
Likes: 0
Received 3 Likes on 3 Posts
Default

I have replaced all the wires, terminal ends (soldered them too), and plugs to the X-link. I am checking my codes with the Flashscan. I am not sure about pending VS permanent. I just hit F3, F2, F1, F4 for all DTC's. I only have C0035, and P0102 as I am running a SD tune. I get the P0102 as soon as it starts, and I have been told that is normal.

If I had to guess, I think it is the throttle body. I think the motor isn't strong enough to hold the blade. I know it is a long shot, but that's all I can think unless someone has other suggestions. It seems like this is only happening to people with superchargers and moving a lot of air.
Old 05-03-2012, 05:01 PM
  #4  
Custm2500's Rude Friend
iTrader: (17)
 
1FastBrick's Avatar
 
Join Date: Apr 2007
Location: JunkYard
Posts: 14,383
Received 786 Likes on 652 Posts
Default

Originally Posted by Gadgetized
I have replaced all the wires, terminal ends (soldered them too), and plugs to the X-link. I am checking my codes with the Flashscan. I am not sure about pending VS permanent. I just hit F3, F2, F1, F4 for all DTC's. I only have C0035, and P0102 as I am running a SD tune. I get the P0102 as soon as it starts, and I have been told that is normal.

If I had to guess, I think it is the throttle body. I think the motor isn't strong enough to hold the blade. I know it is a long shot, but that's all I can think unless someone has other suggestions. It seems like this is only happening to people with superchargers and moving a lot of air.
That's what happen to EvilGMC, the throttle body was bad when he was trying to trouble shot his REP issue...

He Fixed the wires to rule that issue, out because 1 or 2 tested bad, replaced the X-link, and after that he tried a different TB and it fired up with no Issues.
Old 05-03-2012, 05:06 PM
  #5  
TECH Junkie
Thread Starter
iTrader: (9)
 
Gadgetized's Avatar
 
Join Date: Jan 2010
Location: Rochester, NY
Posts: 3,095
Likes: 0
Received 3 Likes on 3 Posts
Default

I have the LS7 TB on it now. I will try an 87mm TB in an hour or so, and report back. I will be going to a 10% OD crank pulley tomorrow so I will be moving even more air. I will see if that trips it sooner. Thank you.
Old 05-03-2012, 07:41 PM
  #6  
TECH Junkie
Thread Starter
iTrader: (9)
 
Gadgetized's Avatar
 
Join Date: Jan 2010
Location: Rochester, NY
Posts: 3,095
Likes: 0
Received 3 Likes on 3 Posts
Default

Well I swapped to the 87mm, and went WOT without going into REP. So it must have been the TB. What really surprises me is that you really need to force the throttle blade with your hand in order to get it to go into REP with the key on engine off WOT. I did it several times with my dad running the throttle, and it acted just like it does when I am driving it. I had him try it while I was running the throttle, and he wouldn't even push it that hard. He thought it was going to break. I didn't realize how much air pressure was on that thing. Maybe when I get time I will put a vacuum gauge on it, and see what it reads at WOT. Let's see if it stays this way with the 10% OD crank pulley.
Old 05-03-2012, 08:50 PM
  #7  
Custm2500's Rude Friend
iTrader: (17)
 
1FastBrick's Avatar
 
Join Date: Apr 2007
Location: JunkYard
Posts: 14,383
Received 786 Likes on 652 Posts
Default

Originally Posted by Gadgetized
Well I swapped to the 87mm, and went WOT without going into REP. So it must have been the TB. What really surprises me is that you really need to force the throttle blade with your hand in order to get it to go into REP with the key on engine off WOT. I did it several times with my dad running the throttle, and it acted just like it does when I am driving it. I had him try it while I was running the throttle, and he wouldn't even push it that hard. He thought it was going to break. I didn't realize how much air pressure was on that thing. Maybe when I get time I will put a vacuum gauge on it, and see what it reads at WOT. Let's see if it stays this way with the 10% OD crank pulley.

Good deal!!! The motor in the TB must not be strong enough for the turbulence the Boost creates... I wonder if there are any tricks that would help reduce the pressure on the blade yet not affect performance. I also wonder if any of the aftermarket throttle body's suffer from the same issues over time...
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ARC
GMT 800 & Older GM General Discussion
57
02-21-2022 10:54 AM
lxcoupe
GM Engine & Exhaust Performance
1
07-30-2015 02:42 PM
Ketis
Trucks and SUV Classifieds
6
07-23-2015 12:37 PM
Offroadunleashed
Trucks and SUV Classifieds
0
07-20-2015 02:25 PM
wheeliE-maxx
Tuning, Diagnostics, Electronics, and Wiring
10
07-19-2015 05:37 PM



Quick Reply: the reduced engine power blues



All times are GMT -5. The time now is 02:31 PM.