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Fuel cut driving me crazy!!!

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fuel cut tune
18K views 44 replies 12 participants last post by  spikester603 
#1 ·
Hey guys,

My car is acting ridiculous. First of all, here are my mods on the 2011 gsr:

ETS Intake, Uicp, Tp.
GM 3 port
Clipse3gt tune.

My car is getting huge fuel cut in first and second gear. Clipse read 50% fuel-cut in first, 30% in second. After my initial tune, the car was great, then slowly reverted to this fuel-cutting mode. I went back to Clipsey, and he undid some barometer thing, and it temporarily went away. After driving around for another week, the car has reverted to limp-dick mode.

-I have tried every combination of asc one off, full off, snow, gravel, and tarmac modes.
- It is not the tune, because Clipse3gt is badass, and whenever he reflashes the car, it pulls really hard. It only gets slow after a week or so, making me think it's some fuel cut.
-It isn't a boost leak, because 3rd and 4th hit harder than Mark McGuire,
-It isn't knock because...well...my car isn't knocking.
-I switched out the blue relay for the black relay
-I have reset the ECU in every way possible
-I have tried every type of throttle attack (partial throttle gets the most torque! :wtfsign:!)
-It is definitely not in my head, because it pulls hard when Clipse does his stuff, first pulled waaay harder when stock.
-I know it is fuel cut because the laptop says so (I only have a mac, so this again is Kris logging the car), and it just feels like the power ceilings off.
-It's not just the fact that higher gears have more load and pull harder, or that first doesn't make as much power because it is such a short gear and the turbo can't spool quickly enough, it goes to like 4,200rpm and then stops accelerating and maintains that velocity until redline. Clearly just getting power cut right?

Has anyone else with a 2011 experienced this?? I've never heard of it for other years, and I know the 2011 gsr has some fuel-cut implementations that other years do not have.

Once dual map-switching is available, I can like...ride it in first hard on a stock map, shift to second, shift to third, switch maps, drive on a tuned map....but that's dumb lol. Do any of the guru's or gearheads know anything about why my car cuts power?!? My vw passat pulls harder in first, no joke. This really kills my driving experience. If someone can fix or resolve this, I will paypal them $20! This problem is really distracting me!
 
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#6 ·
its a program you can download on the forums. You load your datalog file onto it and it will make a dyno graph for you. I heard it pretty accurate.

To the OP, when that happend to me i only had a drop in filter and TP. It was the only time it happend. How much fuel did u have in your tank?
 
#5 ·
Low gas.. Why did you remove the blue relay, is your BOV leaking... Gogogo.
 
#8 ·
BTW, it is not a fuel cut. It is a TPS cut.

It's that or a failing TPS sensor or something with the brake boost system.

It was hitting a TPS limit. I am not sure why it does it. Unless there is a another set of TPS maps for the 2011's where they limit power in 1st and 2nd gear to protect the transmission.

The odd part is we did some 15 plus pulls and the TPS maxes out at 96% and now the car "learns" to cut TPS power...

There is another map or the ECTAS / AWD ecu's are kicking in to limit power.

Very strange....
 
#9 ·
BTW, it is not a fuel cut. It is a TPS cut.

It's that or a failing TPS sensor or something with the brake boost system.

It was hitting a TPS limit. I am not sure why it does it. Unless there is a another set of TPS maps for the 2011's where they limit power in 1st and 2nd gear to protect the transmission.

The odd part is we did some 15 plus pulls and the TPS maxes out at 96% and now the car "learns" to cut TPS power...

There is another map or the ECTAS / AWD ecu's are kicking in to limit power.

Very strange....
i have the 2011 MR. i hope this doesnt cause any problem for you to tune. it be a long drive if i have to drive back and forth to ohio. but im positive i'll be in good hands. i cant wait for you to tune my car :godance:
 
#10 ·
Hi freethriftyz.

I'm sorry to hear you're having issues. In your other post, you mentioned the RAX Patch "Baro Compensation" ROM tweak. That baby's mine. :) I've been watching this evolving story with great interest, as there was a chance my patch was involved. But if your ROM no longer includes the RAX "Baro" patch change, there goes that theory!


According to Clipse3GT, what you have is a reduction in throttle, being perpetrated by the ECU itself. It's as if you're applying 50% throttle in 1st, 70% throttle in 2nd, etc. Thing is, your right foot is on the floor.

In my own vehicle (Ralliart), I've seen "ghost in the machine" TPS reduction only in very extreme conditions... outside that awful traction-control ASC rubbish, that is. Like, when I bounced off the rev limiter in 1st, the ECU actually throttled me back all by itself. I'd clearly triggered the "bad driver" code in the ROM. :)

But yours is something different. There are threads around detailing "issues" 2011 owners are having with their ECUs refusing to permit them to brake with one foot and hold open throttle with the other... to build boost at constant RPM. Why people may want to do this is not relevant here, but they have logged definite ECU-initiated throttle-back.

There is conjecture that Mitsubishi watched all those amusing Toyota owners with drive-by-wire throttle, belting along the freeway screaming "it won't stop! aaarh, I'm going to die, I'm pressing da brake but it won't stop, aaaaah, hey, call my lawyer!" and immediately raced off to add some new "nanny" code to the 2011 ROMs. :p


Assuming I've understood everything correctly, your case is the first I've heard of TPS back-off actually getting in the way of "normal" driving, once tuned.

Clipse3GT will surely keep plugging away at this. Golden may well be able to provide valuable insight as well. I've got all intrigued too, so I'm in.


Anyway, I hope this helps a bit with the background to your issue. Do have a great NY... ECU throttle "ghosts" and all.

Rich

Edit: Clipse's reply beat me to it. Probably because he said more with less words!
 
#11 ·
First of all, thanks to you and clipse for the info, I don't feel totally stranded. Sorry my car is such a mystery.

I think the thing here is like Kris said, a tps cut, not a fuel cut, and my car relearns after a reflash. I didn't know the lingo, but that is a perfect description you and clipse gave. My right foot is at 90% but the car only allows 50% (very weird feeling btw!). I really will pay you guys for helping solve this, but no rush. No knock no problems, no worries! It's just my car is not so fun where it should be!

Good news is that we can put your barometer sensor back on once we find the culprit:) And I agree, it could have something to do with this brake-boosting restriction (I will also pass on frying my rotors, thanks;)), but as far as I know, sequence and some others who have the bboosting issue don't have this.

Clipse, any ideas man? I appreciate all your work, seriously beers on me anytime. Keep me updated! It really gives me peace of mind to know this awesome community has my back. Or maybe you guys just like a good puzzle haha...sucks being the guinea pig tho:wallbash:
 
#12 ·
And Richard, as far as I know, he was going to put the patch on, but we thought we found the culprit otherwise and didn't do it. So there's a chance your ROM might soon be involved actually. I forget if Clipse said he put it on or not this time.
 
#13 ·
The patch was off and all the TPS and limits have been set to stock. The issue went away after 15-20 runs that we did. Then the TPS cut returns.

To me it's like the car has another set of MAP's or a code that forces the car to limit TPS in lower gears if it goes over a certain torque or power level and cut's TPS. It DOES NOT cut boost. Since it still hit's proper boost levels. It cut's the amount the TPS physically opens and puts a ceiling on it.
 
#17 ·
Right now, no one has seen this before or at least hasn't posted about it.

So right now we are not sure what is causing it.

I will talk with Tephra and see if we can't figure something out.

But I am sure it is related to brake boost system in some way, shape, or form.

It is something that I never seen before on 2008,2009,2010's.
 
#23 ·
And don't worry about this man, my car is still waaay faster (except first gear is a dud). The car def. feels better than stock and a very noticeable power bump. Like clipse said mine is the first example of this, but the ratio of 2011 evo owners to 2011 evo owners who tune is pretty unbalanced. We have a small selection pool, a lot less people than you think tune.

On the off chance that yours does this, its STILL worth the money for the tune haha. I just want that extra power in first gear (and second)! The guru's will come up with something, I have no doubt. Again, I know it's a long drive, but ur car is probably fine, and the tune is worth it anyways!
 
#19 ·
Don't see how. Here's the way Clipse3T described this issue...

1st Gear is getting a 50-60% TPS only when pedal is @ 100%
2nd Gear is getting a 70-80% TPS only when pedal is @ 100%
3rd Gear [is getting] 85-96% TPS range when pedal is @ 100%

There's a mechanism at work here. We just need to drag it out into the open...

Rich
 
#20 ·
My TPS never reads above 86% or something like that which is WOT for me. I thought this was the same for everyone >.>
 
#22 ·
Idk, most of our logs were reading at consistent 92ish%. Either way, 50% isn't right...Isn't there a way to just disable all forms of tps functions other than just straight up throttle position? Or maybe is there a torque limiter like the MR's on the newer 2011 gsr's?

My only thing is I don't see how it is tied in with bboosting, since i'm not even touching the break at all. It feels like safe mode...I'll just remain quiet in this thread unless my car changes or you guys come up with something. Thanks for the help everyone!
 
#24 ·
It's not 86%.. IT's 86Degrees out of a possible 90...... The butterfly valve starts at 0DEG and then both valve sides open 90 Degrees toward the intake Manifold......
 
#26 ·
Hahaha-- Are you in IT?
 
#30 ·
When you put it like that it doesn't seem very bad at all! tps isn't bad for the car is it? As long as this thing is not about to blow. There wasn't any knock so I'm guessing this safety mode is actually pretty safe. Very ironic haha. I'll try to keep that positivity going until a patch comes around:D
 
#36 ·
I've been on vacation...

Anyone have logs of this happening?

Has it been proven to be independent of the RAX patch?
Yes, independent of RAX Patch - it still occurred without any patches in place.

No, haven't seen any logs.

I'd like to see the ROM itself too.

Rich
 
#34 ·
Hey guys,
I went back to Clipsey, and he undid some barometer thing, and it temporarily went away. After driving around for another week, the car has reverted to limp-dick mode.

- It is not the tune, because Clipse3gt is badass, and whenever he reflashes the car, it pulls really hard. It only gets slow after a week or so, making me think it's some fuel cut.
torque! :wtfsign:!)
-It is definitely not in my head, because it pulls hard when Clipse does his stuff, first pulled waaay harder when stock.

Has anyone else with a 2011 experienced this?? I've never heard of it for other years, and I know the 2011 gsr has some fuel-cut implementations that other years do not have.
Why cant it be the tune?
 
#38 ·
Kris has tuned hundreds of evo's, none of them with this problem. This plus the fact that the 2011's did indeed get some extra safety maps hidden within the ecu makes me really feel as if my car is the anomaly, not the tune.
 
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