[ls1car]

So I just installed a Cobb cat-back and Stage 1 tune with the AP. Last night at full throttle the car violently cut-out at around 4-5k RPM. It did this in 3rd gear first and then immediately again in 2nd gear at full throttle. It feels like fuel cutting out. Unfortunately, I was not logging at the time.

I have read all about the fuel pump relay going out, and I have also experienced some full throttle hesitation issues before I made any modifications to the car (always thought it was full starvation after hard turn).

I know the problem presented by a failing fuel pump relay is running lean, but I haven't read about it causing fuel cut-out. Is it possible that the fuel pump relay can be the cause of the cut-out issues i experienced last night. If not, I have no idea what to think!

 

[xezerax]

You have a boost gauge? How much boost are you hitting?

 

[Tdiggity]

I have the same issue. No gauges yet


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[WWEvo]

Here the link to what i think it is, same thing happend to me and I couldnt figure it out until i met with Golden and he showed me it
http://www.evoxforums.com/forums/showthread.php?t=18366

 

[chetrickerman]

If it felt like you hit a brick wall, then a second later it was fine, then you most likely hit the boost cut from over boosting.

Datalog your car.

 

[xezerax]

If it felt like you hit a brick wall, then a second later it was fine, then you most likely hit the boost cut from over boosting.

Datalog your car.

x2

 

[ls1car]

You have a boost gauge? How much boost are you hitting?

No boost gauge yet (been waiting for the DSG A-pillar!)

I will definitely be data logging next time I take it out! And hopefully (or not) it will happen again.

I checked the Fuel Pump Relay just to be sure. I did the "salt-shaker" test to listen for a rattle. I heard something. But I checked the other relays and they all make the same noise if you shake them hard enough (i hope i'm not damaging them all lol).

I have a 2011 with 22k miles. I've already ordered two new "new black" relays from SSP.

I will also be checking the vacuum line to the fuel pressure regulator. I'll let you guys know what i find

 

[fishstix]

What do you mean when you say "violently"? Does the car buck around?

I've had this problem for months now. When I get to 5k RPM at WOT in 3rd or 4th gear I spray a ton fuel from my exhaust and I lose all power. It's not white smoke. Crappy tune leads to crappy problems.

 

[ls1car]

Not sure if this is good or bad news, but the FPR vacuum line was NOT disconnected.... but i zip-tied it anyway. Any other ideas???? I guess all I can do now is data log.

 

[ls1car]

What do you mean when you say "violently"? Does the car buck around?

I've had this problem for months now. When I get to 5k RPM at WOT in 3rd or 4th gear I spray a ton fuel from my exhaust and I lose all power. It's not white smoke. Crappy tune leads to crappy problems.

i mean "violent" in the sense that it feels like going from 100% throttle to 0% throttle instantaneously at 5k RPM. It felt just like the fuel cut-out at 115 mph in my camaro.

 

[WWEvo]

Not sure if this is good or bad news, but the FPR vacuum line was NOT disconnected.... but i zip-tied it anyway. Any other ideas???? I guess all I can do now is data log.

Damn, I was hoping it was something simple. My car would cut out at WOT and it was the line that popped off. Hopefully its not something bad

 

[vegittoss15]

i mean "violent" in the sense that it feels like going from 100% throttle to 0% throttle instantaneously at 5k RPM. It felt just like the fuel cut-out at 115 mph in my camaro.

That's boost cut, buddy. Your AP can somewhat log boost, so check that.

 

[Clipse3GT]

Sounds like your overboost protection kicked in y0...

You need a tune to fix it. Since you are overboosting over the safety settings. Plus you need to zip tie the line at the manifold end not FPR.

 

[ls1car]

Sounds like your overboost protection kicked in y0...

You need a tune to fix it. Since you are overboosting over the safety settings. Plus you need to zip tie the line at the manifold end not FPR.

what causes boost cut? Or i guess the more important question is what causes overboost? My only "tuning" option now is to return to factory tune with AP. Should I call Cobb and see what's up???

 

[Tdiggity]

I have Perrin TBE, AMS CAI, and I have an E-Tune from AMS, so I guess I just wasn't expecting it to be the tune


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[weebles]

Another testament to cobb OTS maps being no damn good.

Custom tune or nothing. :duh:

 

[fishstix]

I have Perrin TBE, AMS CAI, and I have an E-Tune from AMS, so I guess I just wasn't expecting it to be the tune


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You have much to learn young Padawan

 

[bravozero]

Overboosting.

I had this happen on my Ralliart when I reinstalled the stock boost pill backwards. Got up to about 4500 RPM wide open, car felt like it went from quickly accelerating to a dead stop instantly, backfired, and threw a CEL immediately. Fixed the boost pill issue, reflashed the stock ECU basemap, and it was fine afterwards.

The log showed that boost went up to 30 psi at about 4300 RPM, scared the shit out of me because I thought I blew my engine.

 

[Tdiggity]

Just talked to the guy I bought the car from. When he got the tune done from AMS it only had the short ram intake on. It now has the cold air extension so I was wondering if this could be causing the issue. He sold it to me with the cold air extension but it wasn't installed yet (he didn't want to have to take the bumper off) so I installed it afterwords thinking the tune accounted for that. Apparently it didn't. Think this could be part of the issue?


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[HappyMint]

Just talked to the guy I bought the car from. When he got the tune done from AMS it only had the short ram intake on. It now has the cold air extension so I was wondering if this could be causing the issue. He sold it to me with the cold air extension but it wasn't installed yet (he didn't want to have to take the bumper off) so I installed it afterwords thinking the tune accounted for that. Apparently it didn't. Think this could be part of the issue?


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So you changed your exhaust AFTER the tune? Thats your problem.. Exhaust mods WILL cause overboosting. Time to get your tune updated before you cost yourself big :$::$::$: