Reduced Engine Power mode help

[JUSTASBC]

I have been having problems with my truck going into REP mode. I have replaced the wiring from the TAC to the T-Body, and tried 2 different throttle bodies. I get P2101 for a restricted throttle blade. The blade moves freely, and it opens completely. When the engine is off I can move the throttle through the entire range of motion, and never get a code. When the engine is running with my LS7 T-Body on it, it will always go into REP if I hold it at about 70% TP, or go WOT. I am using an X-Link on it also. Is there any way to eliminate this problem, or do I have to go with a cable driven T-Body? I have increased {C3906}, and decreased {C3907} without any change on the outcome. I had a pulley on it and was getting about 10PSI of boost, and would occasionally get P2101 when I was going through the traps. I increased the boost to 13PSI, and now I get it all the time.

[Chuck L.]

Same problem if you bypass the blower??

[JUSTASBC]

I ended up switching it over to an 87mm throttle body. I disabled quite a few things in the tune and changed the max TPS. I can now go WOT without it going into REP mode. I still however get REP mode when it idles. I am considering switching it over to a cable driven throttle body, or selling it. If I start it to warm up, it will constantly die, and you have to clear the codes.

[Chuck L.]

Post your tun file and some logs...I'm sure 1 of the gurus will be able to help!

[JUSTASBC]

This has been extremely frustrating for me. I paid one tuner to tune it, and he was unable to get it anywhere near acceptable after months of messing with it. I spoke to 2 other very experienced tuners that helped a little, and one very new tuner that couldn't help at all. I have been working on this truck since last July, and it is now running %1000 better, but still real bad. It starts and idles at 10:1 AFR(I have lowered {B3642} with very little effect), and dies after 22 seconds if you don't touch the throttle. I have spent numerous months on the REP mode problem, and now do not get it if I run a truck TB at WOT. It did last for 2 min and 45 sec, but for some reason now only lasts 22 seconds. When I can get it warmed up, it will run at about 14.2:1 AFR where I want it. If I put it in neutral going down the road, it will rev to 3500 RPM's (I have messed with the throttle cracker for hours on end). Sometimes when I start it up, it will rev to 2k+ RPM's, and other times it will start properly, there is no telling when it will start OK. I am beginning to think that the computer might be fried due to the amount of tunes I have loaded in it. I would have to guess that I have loaded somewhere around 1000 tunes in it.

[JUSTASBC]

For some reason I can not load my tune on here. I have tried two different computers. I would be very happy to email my tune to anyone that would lke to see it. My email is dwrobb99@yahoo.com

[ScarabEpic22]

Just emailed you, Ill post it up here for everyone to see when I get it.

Can you run through your exact setup? I have no idea what truck you have this engine in, what turbo/supercharger, injectors, MAF, MAP, etc. What is a x-link?

1000 tunes should still be ok, do you have another PCM to swap out and try?

[JUSTASBC]

I do not have another PCM to swap out. I am seriously thinking about going the cable driven route if I can't get this working. If I could make a cable work. Lol

The truck is an 05 Joe Gibbs edition Silverado. The truck did not come from the factory with a supercharger. I decided to get a Magnacharger as they were optional on my truck. Since I was adding that, I decided to do Texas Speed and Performance 2.5 cnc'd heads, 224/230 cam on a 114, long tube headers, X-link (to adapt the stock truck 8 pin TB plug to the car 6 pin plug) 87mm T-body, CAI, and water/meth injection. I started the system with a 2.9 pulley and about 10PSI of boost. I would occasionally get P1516 going across the traps, and was advised to switch TB's to correct the problem. I put on an LS3 T-body, and would occasionally get P2101, and just assumed I couldn't fix the problem. I ended switching to a 2.6 pulley, and it increased my boost to 13PSI. Well then I got REP all the time if I rolled into it slowly with the LS3 TB anything above 60% TPS or so went into REP with P2101. I swapped the 87mm TB back on, and would get P1516 when I went WOT. I ended up nesting with the tune, and have seemed to eliminate the WOT P1516 (I think it was the fact the TB would only show 98.8% when the pedal was at 100%, so I lowered the WOT to 98.8%), but still get the REP at idle. If I let it idle without touching the throttle it went into REP with P0068, P0102, and P0106. If I touched the throttle when I started it, would idle forever without REP. Well now it will only idle about 20 seconds before it goes into REP.

I am using a Semi OLSD COS3, and there is no MAF installed at all. Thank you for helping.

[Chuck L.]

Apply in this case??
http://www.silveradoss.com/forums/topic/51572-reduce-engine-power/

[Chuck L.]

Apply in this case??
http://www.silveradoss.com/forums/topic/51572-reduce-engine-power/

http://www.hptuners.com/forum/showthread.php?t=32080

[ScarabEpic22]

Here is the tune file for the truck in question, REP mode.tun.

First off, fix the out of range cells. B6615-B6620 are all out of range when opened. Tunes can do weird things when values are out of range.

P0068 is a rationality test for the ETC that is triggered when the airflow is above what the PCM expects. You shouldnt have to disable the test, but it might work. You've already tried to take the TPS out of the equation, cant hurt to disable this code too. Just be careful, this controls the throttle in case of a runaway situation, if it starts revving with no throttle input shift to N and kill the key.

You are getting P0102 and P0106 because you havent turned off the codes in the Diags section. P0102 is a MAF-related code, I think all of them need to be disabled to really kill the MAF.

Have you adjusted C6102? Might need some work, if the PCM sees more airflow that what it expects it will throw a REP code.

Do you need to adjust C3004 Predicted MAP Min? What about C3906 and C3907, those are TPS related tables.

I have adjusted the DTCs according to the EFILive COS tutorial and fixed the OOR values, it is REP Mode_0001.tun.

What is up with your B3647 Commanded Fuel table? You're commanding 14.7 at ALL RPMS until 95kpa. Probably not a good thing...

Also I just remembered there are ETC tables in the tune that are activated ONLY when you have your FlashScan plugged in. Plug in your V1/V2 and open the tune file. Look under Engine->Electronic Throttle (red folder) at the tables in there. Under the parameters section there are a few cells for idle TPS adjustment... And B2307, B2308 might need to be adjusted to eliminate your REP. Dont know what max TPS should be, but currently it's set at 98.8%, can go to 100% if need be.

[JUSTASBC]

B6615-B6620 was set that way by my original tuner. I will try changing that and see if it helps.

I have disabled P0068, and I get the same REP results, except the DTC doesnt show up when I check my codes.

I thought I disabled P0102, and P0106, but must not have done it properly. I didn't realize they were under the tranny too.

I have tried messing with C6102, but with no luck. Maybe I will have better luck with the other things I am changing.

I have changed C3004, but will try again.

I have adjusted C3906, and C3907, but will try again.

B3647 was set that way by my original tuner. From what I assume it will only use the STFT's when it is set to 1.00. It is at .99, and should be unactive. I am rtunning in straight OLSD now.

Thanks Erik, I will see if this helps. I will let you know. I don't have too many good days of tuning left. It ,might have to wait till next year.

[driver456]

Not sure if you are still having problems,Change B2706 to 2.8,B2713 to 18 and change B2717 to .254 Those are the Electronic Throttle tables,Let me know if that cures your REP................Paul

[JUSTASBC]

Paul,

I think I might have gotten it straightened out. I ended up putting my 87mm truck TB back on it, messed with the tune a bit, and have not had a problem (knock on wood). This is a summer only vehicle, so it will be a few more months before I can try your suggestions. I will try them in the spring and let you know. Thanks for your help.

[chris10an]

Hello. I'm using the x-Link to with no problems. Did you terminate the X-Link properly?
Chris.

[joecar]

Hello. I'm using the x-Link to with no problems. Did you terminate the X-Link properly?
Chris.Say again...!?!?

[chris10an]

Car style LS2/LS7 (e.g. Corvette) 90mm throttle body- The loops should be cut and the ends insulated to prevent contact.

I'm not a specialist in this, maiby i answered wrong here..... i did not read it all...
In that case sorry.. But this is the way we use them in Norway, with no problems. The X-Link..
Chris..

[JUSTASBC]

I am still having problems with REP mode. I have tried all the suggestions. I currently do not go into REP mode idling, but I get it at WOT. I have a new LS7 throttle body on it now, and it trips every time I go WOT. Does anyone have any suggestions? Thanks. Would it help anyone if they viewed my tune or a log? I am getting P0102 on a COS SD tune.

[driver456]

What code are you getting now when you go into REP mode.P0102 code,Aren't you suppose to get that code on a SD tune?

[JUSTASBC]

Well I was advised it could be the throttle body. I am not getting any codes that would put it in REP mode. I ended up swapping to an 87mm truck throttle body, and it hasn't went into REP mode yet. I think that the air passing the blade is actually forcing it closed making it go into REP. I turned the key on with engine off, and went WOT. I then forced the blade closed with my hand and it went into REP just as if I was driving it. I am really surprised at the amount of force it took to make it go into REP. When I took a log while driving, you can see the TP% lowering right before REP mode. I am putting a 10% overdrive crank pulley on it tomorrow, so I guess we will see if too much air will effect the 87mm TB too. I will update this post with the results.

[driver456]

In post #18 you say your going into REP mode,Now in post #20 your not getting any codes that puts you in REP mode.There is other ETC tables that have to be adjusted.Awhile back there was a problem with efilive and the ETC tables,But was fixed,Do you have the latest upgrades?.In your 1st post you say you were getting P2101 what code is that?

[JUSTASBC]

Well from everything I gathered P2101 was caused by bad wiring. I had previously replaced a section of wiring as is described in the service bulletin, then I got the P2101 (I had never gotten it before). I then decided to replace every bit of wiring, plug, and terminal from the TAC module to the X-link and solder all of the crimp connections just to be safe. I have since not gotten a P2101 code. I originally had a 2.9 pulley on my truck, and it occasionally went into REP at WOT when the RPM's were high with the LS7 TB. I switched to a 2.6 pulley, and got REP mode every time I went WOT. I ended up switching to a tune that I got from Justin at Black Bear, and only got REP when I had the LS7 TB on it. I am not getting any codes that would trigger REP (the P0102 is the only thing coming up, but I am running an SD tune). Every time I go WOT with the LS7 TB, I go into REP at about 6400 RPM's or so. If you watch the log on the TP%, you can see it closing a few degrees before REP, just like if I am forcing it closed with my hand. (When I force it closed with my hand I don't get a code either) The only thing I can think is that the vacuum is so high by the increased airflow that the plate can't stay opened. It seems like only roots style supercharger guys moving a lot of air are getting this problem. The turbo guys pushing air through the TB are not getting this problem. This has me really baffled. I got tied up today, but am going to see if the 10% OD pulley triggers REP with the 87mm truck TB. I don't have the very latest software, but I have the one right before it.

[driver456]

Post up or send me one of your logged runs where it goes into REP.If you can log a run where you just roll the throttle on up to WOT

[JUSTASBC]

Here are a few runs. One with the engine off and forcing the throttle blade closed by hand until it hit REP mode.

[driver456]

Copy and paste these tables that I changed from your tune.They only have to do with ETC & TP Look them over first if you want. C6102-C3906 The next one's are the RED FOLDER B2706-B2713-B2717-B2702 It might not work,But give it a shot.I had a few people tell me my DBW NW102mm TB & Intake will not work under FI,Well it works @ 40% and any where inbetween that & 100% :grin:

[JUSTASBC]

Paul, thanks. I will not be able to try this out for a few days, I will report back.

[JUSTASBC]

Paul, thanks for your help. The problem seems to be resolved.

[JUSTASBC]

Well, I took my truck to the track last night, and ran it 5 times. It went into REP all 5 times. I do not get REP when it is idling now (Thanks Paul), but only get it when I am going WOT. I am not getting any codes, just the REP mode. I have messed with the airflow tables, and can not seem to get rid of it. Can anyone think of any other way of correcting this?

[joecar]

There's various sanity tables for ETC/TP, MAP, MAF, did you look at all of them...?

post your current tune file and some log files showing where REP triggers, someone will see something.

[JUSTASBC]

I will post in a couple hrs when I am done with work. I did look at the tune, and some DTC's were set to no mil. I turned them back and am showing P2101 for a restricted throttle blade. When the engine is off, the blade moves freely, and will not go into REP unless you force the blade with your hand. When it is running, it will go into REP when the RPM's get high.

[JUSTASBC]

Here are a couple quick runs of it going into REP mode with a tune. Thanks

[joecar]

I'm looking but I'm not sure I see why...

[driver456]

Give me some time,I'm looking at it now.Also check your throttle blade by hand @ WOT the blade should be at a 90 degree angle,See if it goes past that.Mine did,And If I remember I drilled a hole and put a stop set screw in to stop the blade from going past the 90 degree angle.The air being forced in might be trying to flip the blade the other way if it goes past the 90 degree angle.Just a thought.

[driver456]

Did you update efilive? There was a "bug" awhile back that affected the throttle tables.I see in your log that the throttle % is moving around a bit.You might have to go with a cable TB.Boost pressure might be moving the blade around to much.

[driver456]

Just for the heck of it,Try scaling your injector flow rate downward about maybe 25%,You would also have to minus 25% off your VE table also.Do you tune your truck or does somebody else?

[JUSTASBC]

I am doing a majority of the tuning. Justin at BBP is helping when I run into problems. He isn't sure why it is happening either. I just tried my LS7 TB back on it, and tripped P2101. I also increased B0120, and that didn't help. DRX is helping too. I will try to update EFI Live to see if that helps. If I knew I could go to a cable I would do that. I'm not sure if I even can go that route. I have searched all over and can not figure out how to do it.

I would really like to connect the wires coming from the TAC module that tells the desired TPS, and the actual TPS off of the TB to eliminate this problem but DRX says it will trigger REP because the signals are too close.

[driver456]

I read your 1st post again.You are using a X-LINK What is it and what does it do and why are you using it.OK never mind,Looked it up,TB adapter.What TB was on the truck before the SC and what pcm are you using.

[JUSTASBC]

I am using the factory PCM #12592618 with a COS 3 semi loop SD. Currently I am just running straight SD though. The factory TB is a 78mm (I unfortunately can't put it back on as it is a 3 bolt, and I have to now use a 4 bolt TB). I have two 4bolt TB's. One is 87mm that would come on the newer style trucks, and the other is a 90mm that would come on a new Camaro (LS3/LS7 style).

[driver456]

Have you tried the stock 78mm TB with the factory harness/wiring? I would still update your EFILive.

[JUSTASBC]

I can't try the 78mm TB as it is a 3 bolt. The flange is now for a 4 bolt. I had a typo earlier, and fixed it after you posted that.

Well I reduced my blade to 85% hoping that would do the trick, and still got the same problem. I would be happy to go to a cable driven TB if anyone knew how to do it.

[driver456]

Did you update your efilive yet?

[JUSTASBC]

I will try it again tonight. For some reason I always have problems wen I try to update. It says Bootblock version is OK 2.07.03 Jul 25, 2011, and Firmware version is OK 2.07.22 Aug 23, 2011. It wont let me update it

[JUSTASBC]

I have updated everything. Later today I am going to start from scratch, and load the original tune in my truck, and make it into a COS. I will post back with the outcome.

[driver456]

Good idea

[JUSTASBC]

Well I installed the newest EFI Live versions, and it still goes into REP. The only thing the update did for me was make the program go into Demo mode when I open a tune without the Flashscan plugged into my laptop.

[driver456]

If you want to try one more thing,Put a bigger pulley on and lower the boost and see if it goes into REP.Other than that,You probably have to go to a cable TB.

[JUSTASBC]

I didn't get it as much before I increased the boost. I want to try a few more things tomorrow. I built a divider that lined straight up with the blade when it was WOT, and that didn't help. I would like to apply vacuum to the TB tomorrow and see if I can get it to trip. I just can't understand why turbo guys don't get it, and they move much more air than I am. On performancetrucks.net people stated they had this problem, and switching to a Nick Williams 102mm TB resolved their issue, so it has to be something strictly with the TB.

[driver456]

Thats what I have on the vette,A NW102mm TB.I ran the car a few times at 100% throttle,But only about 10# of boost and it ran fine.Soooooooo maybe you have to get your self a NW TB before you pull your hair out :mrgreen:

[JUSTASBC]

Just to update everyone, I figured the problem out. I ended up getting an LS2 throttle body and it cured the problem. The air entering the inlet pipe was working like an airplane wing, and lifted the back of the blade up. That was forcing the blade closed, and causing REP. The throttle body opens in the opposite direction, therefore the air entering was forcing the blade opened. My logs showed that the TPS was rock steady. I would have loved to try flipping the throttle body to see if it had the same effect, but I didn't have the room.

[DrX]

C3904 and C3905 need to be put back to stock or the the TPS tests are going to run all the time rather than just under steady state conditions(55-65kPa).

[joecar]

Just to update everyone, I figured the problem out. I ended up getting an LS2 throttle body and it cured the problem. The air entering the inlet pipe was working like an airplane wing, and lifted the back of the blade up. That was forcing the blade closed, and causing REP. The throttle body opens in the opposite direction, therefore the air entering was forcing the blade opened. My logs showed that the TPS was rock steady. I would have loved to try flipping the throttle body to see if it had the same effect, but I didn't have the room.Thanks for the update...

good conclusion, for future reference I'm interested to know how you figured out the airflow was pulling the blade, I'm also curious about flipping over the TB.

( is there a pid that shows he blade's actual position...? )

[joecar]

C3904 and C3905 need to be put back to stock or the the TPS tests are going to run all the time rather than just under steady state conditions(55-65kPa).Good point.

[JUSTASBC]

Thanks for the update...

good conclusion, for future reference I'm interested to know how you figured out the airflow was pulling the blade, I'm also curious about flipping over the TB.

( is there a pid that shows he blade's actual position...? )

Sorry for taking so long to respond. Well it would never go into REP when it was off with the key on. I could hold the pedal wide opened all day, and it would work fine. Well when I started turning up the boost, it would go into REP. I always got P2101 for a restricted throttle blade. If I left the engine off with the key on, and forced the blade closed with my hand, I would get P2101. I decided to start logging the pedal position, and the throttle position. Well the pedal was always working properly, but the throttle blade was slightly closing at higher RPM's, and forcing it into REP. I made a divider that let air split easier in front of the throttle body blade. Well it helped a little. I heard that the LS2 throttle bodies open in the opposite direction, so I bought one. When I hooked it up, it worked great. I will be turning up the boost soon, and will see if the LS2 throttle body continues to work properly. I will keep everyone updated.