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Reduced engine power problem

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Old 03-28-2017, 05:30 PM
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nutbuster
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Default Reduced engine power problem

I have a 2002 Z06 with an LSX 427, I have installed a Procharger F1X. Since the installation I constantly get a reduced engine power light and the engine goes to 2000 rpm and the throttle has no affect until I reset the computer. I understand the purpose of the reduced engine power light and this system. What I do not understand is why I keep getting this light?

The car goes to REP anytime I try to drive attempt to tromp on the throttle and the rear wheels spin, it immediately goes to REP and I have to go thru the reset on the computer. I have a Nick Williams throttle body on it now that is supposed to be made for supercharged motors. I have tried numerous throttle bodies and still get the same results. I have the car at the shop that built the motor but they have not been able to figure this problem out?

I have invested tons of money in this car and not able to enjoy all of this power due to this issue Does anyone have any ideas on what to do?
Old 03-29-2017, 01:16 AM
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wesam
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Check this we are in the same boat

https://www.corvetteforum.com/forums...-corvette.html
Old 03-29-2017, 09:34 AM
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Pekka_Perkeles
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Originally Posted by nutbuster
I have invested tons of money in this car and not able to enjoy all of this power due to this issue Does anyone have any ideas on what to do?
Switch to a cable TB and a PCM that has IAC drivers & hardware. Although your PCM may have those already:

https://www.mrk-motorsports.com/gm-iac-pcms/
Old 03-29-2017, 11:30 AM
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Thanks I will give it a shot. I have been dealing with this so long I am ready to sell the damn thing! Thanks Again I hope it works?
Old 03-29-2017, 12:01 PM
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Originally Posted by nutbuster
Thanks I will give it a shot. I have been dealing with this so long I am ready to sell the damn thing! Thanks Again I hope it works?
Well, there is also other reason for REP as well. Hitting hard-coded limit in PCM is one of them but that can be fixed with scaling the tune. I doubt that's the problem with your car.

Now, if you do have a problem with ETC TB and so called TAC module, at the moment the only way to fix it is to go with cable TB.

Trying that should be not too expensive, but you'll lose traction control in your 'Vette. If it matters..
Old 03-29-2017, 12:20 PM
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Check out the corvette forum thread that Pekka linked. I have a listing of everything that I have changed and it still didn't fix the problem.

Also, post up in this thread if you are a member to let HPTuners know that this problem still exists. It's actually been an issue since 2007.

https://www.hptuners.com/forum/showt...o-427-Corvette


Pekka have you switched any C5s or other cars from DBW to cable?

The only time I've needed traction control or more importantly active handling, is in the rain. I got caught in a downpour one time and the car hydroplaned even though I was at 45 mph on the highway. If it weren't for AH, the car would most likely have crashed.

Last edited by Turbo-Geist; 03-29-2017 at 12:23 PM.
Old 03-30-2017, 08:32 AM
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Originally Posted by nutbuster
I have a 2002 Z06 with an LSX 427, I have installed a Procharger F1X. Since the installation I constantly get a reduced engine power light and the engine goes to 2000 rpm and the throttle has no affect until I reset the computer. I understand the purpose of the reduced engine power light and this system. What I do not understand is why I keep getting this light?

The car goes to REP anytime I try to drive attempt to tromp on the throttle and the rear wheels spin, it immediately goes to REP and I have to go thru the reset on the computer. I have a Nick Williams throttle body on it now that is supposed to be made for supercharged motors. I have tried numerous throttle bodies and still get the same results. I have the car at the shop that built the motor but they have not been able to figure this problem out?

I have invested tons of money in this car and not able to enjoy all of this power due to this issue Does anyone have any ideas on what to do?
Originally Posted by wesam

You two guys send me your tunes if you, have HPT. PM me for my email.
Old 04-04-2017, 04:56 PM
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Default fixed the REP

Well I tried an LS2 throttle body and a smaller pulley on the supercharger? It seems to be okay now! At least this week?
Old 04-05-2017, 12:50 AM
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Originally Posted by BLOWNBLUEZ06
You two guys send me your tunes if you, have HPT. PM me for my email.
^^^^ this guy will almost certainly be able to fix it
Old 04-05-2017, 11:24 AM
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Pekka_Perkeles
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Originally Posted by nutbuster
Well I tried an LS2 throttle body and a smaller pulley on the supercharger? It seems to be okay now! At least this week?
Not surprising.

Getting rid of NW102 usually helps.
Old 04-05-2017, 03:20 PM
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I had the good LS2 tb and I still had problems. Switched to the TPIS custom 90 MM TB and have has zero issues for about 2 years now.
Old 04-05-2017, 04:59 PM
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Originally Posted by fotoboy
I had the good LS2 tb and I still had problems. Switched to the TPIS custom 90 MM TB and have has zero issues for about 2 years now.
I remember you had that problem. What boost were you running?? Haven't seen you on here in away.
Old 06-08-2017, 02:55 PM
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Default Ls2

Well after I switched to the LS2 throttle body all of my REP problems disappeared I am running an F1X pro charger with 15 lbs of boost It made 1025 RWHP on 93 with a big pulley on the F1X. My tuner said I should try E85 and would gain a lot more RWHP! I can barely keep it between the white lines now, don't think I could use any more HP!
Old 06-08-2017, 10:59 PM
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winters97gt
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Nice! Saw the video online today.

This seems to be a common issue. When I bought my last C5 that I just sold, it did this every pull, even with the owner picking me up from the airport. 900 mile drive home, it kept doing it in the 875rwhp range. Raced buddies the 2 days the engine lived after I bought it, and it did the same thing.

My first new motor, same thing. That let go too.

Explained that to my last tuner before I sold it last month with a solid motor. Beat on the car after tuned to make sure it was good, and sure enough it was gone. Whatever Bret knows above seems my tuner does too because this is a common issue.
Old 06-09-2017, 06:09 AM
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Originally Posted by winters97gt
Nice! Saw the video online today.

This seems to be a common issue. When I bought my last C5 that I just sold, it did this every pull, even with the owner picking me up from the airport. 900 mile drive home, it kept doing it in the 875rwhp range. Raced buddies the 2 days the engine lived after I bought it, and it did the same thing.

My first new motor, same thing. That let go too.

Explained that to my last tuner before I sold it last month with a solid motor. Beat on the car after tuned to make sure it was good, and sure enough it was gone. Whatever Bret knows above seems my tuner does too because this is a common issue.
Video???
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Old 06-09-2017, 08:08 AM
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Originally Posted by helga203
Video???
Yup
Old 06-09-2017, 01:22 PM
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Originally Posted by winters97gt
Yup
Where can I c the video???

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Old 06-10-2017, 02:05 AM
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winters97gt
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Originally Posted by helga203
Where can I c the video???
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Old 06-10-2017, 02:21 AM
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winters97gt
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The amount of cars I've seen blow up on pump plus meth is staggering over 17 years. Personally, I think 900+ is too much with pump + meth. I stopped at 850 in my C6. Just not a lot of room for error. 700-800 is it for me.

OP, I'd leave the car at its power level if you're on a 4 bolt block. Maybe 1100, but definitely use Chuck's advise and go E. All those F1x cars that made 1200+ from our Houston shops.... Where are all of them now? All gone, blew up soon from multiple tuners. Leave it at a 1000-1100 on E and meth and call it a day. Badass car btw.
Old 06-10-2017, 11:30 AM
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Originally Posted by winters97gt
The amount of cars I've seen blow up on pump plus meth is staggering over 17 years. Personally, I think 900+ is too much with pump + meth. I stopped at 850 in my C6. Just not a lot of room for error. 700-800 is it for me.

OP, I'd leave the car at its power level if you're on a 4 bolt block. Maybe 1100, but definitely use Chuck's advise and go E. All those F1x cars that made 1200+ from our Houston shops.... Where are all of them now? All gone, blew up soon from multiple tuners. Leave it at a 1000-1100 on E and meth and call it a day. Badass car btw.


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