WOT issue... what could it be?

[ill_eagle94]

OK... my mods are in my signature.

This has started once I installed the Forge BPV, which leans me towards it being the culprit, but I have other theories as well.

Basically, under WOT, any gear I can get traction in (3rd and up), I get some hiccuping here and there above around 4000 RPM. I started out with the Yellow spring in the BPV but never went WOT with it in there. I then found that according to the spring chart, the Blue spring was the proper one for the boost pressure that the MS3 runs. I went WOT a few times on Tuesday and stumbled (no pun intended) upon this issue, as well as Thursday and today.

Tonight I decided to go back to the Yellow spring, thinking maybe it was holding too well (don't know how that is even possible seeing as boost is regulated by the wastegate). Obviously, it's still happening.

Tomorrow, I've got the day off, so I'm going to put the stock BPV back in and see if the issue goes away and I have two theories of what may happen. One, it will go away and I'll be fine with the stocker. Or two, what I think is most likely, it will continue to happen.

My guess is now that the air is getting cooler here in NH, something is going on where I'm hitting fuel cut due to the temps allowing me to flow more air, thus build more boost. The other possibility is that I really am building more boost now and it's going beyond the PCMs stock threshold for what it's programmed to allow and I'm getting boost cut.

If it's boost cut, I can just get the Boost Cut Defender and I'll be fine, as I'm not raising the boost with any sort of boost controller, I'm running stock pressure. OR, is fuel cut and boost cut the same thing, just worded differently.

What do you guys think?

Thanks,
-Sean

 

[Maxxpwr]

it sounds alot like fuel cut. but you shouldn't be anywhere near fuel/boost cut without raising boost. even if its cold. I would definitely say put your stocker back in tomorrow and see if it doesn't go away. if it doesn't drive it over to the dealer with the stocker in and its their problem. I really dont think its the bpv.

 

[ill_eagle94]

it sounds alot like fuel cut. but you shouldn't be anywhere near fuel/boost cut without raising boost. even if its cold. I would definitely say put your stocker back in tomorrow and see if it doesn't go away. if it doesn't drive it over to the dealer with the stocker in and its their problem. I really dont think its the bpv.

LOL, I can't go back to the dealer with a DP/TP installed. I'd have to go back with the stock valve and stock cats reinstalled.

 

[Maxxpwr]

they can only not inforce their warrenty if they can prove that your problem is because of your mods. from what your describing i see no possibility at all of this problem being because of a full exhaust system. cats or no cats.

 

[ill_eagle94]

I understand that. I'd still hate to have any sort of issues with the dealer. Either way, the stocker should be going back on tomorrow. If that is the issue, I'll just save the BPV for the point at which I do more upgrades such as ECU and upgrade the turbo.

I may also just try resetting the ECU and letting it relearn as I did when I installed the DP and RP. It is funny, I was getting an intermittent CEL (assumed o2) before and since the BPV, there has been no CEL.

 

[controlo]

my car stumbles as soon as i shift and go WOT quickly. my mods are, test pipe, injen CAI... i'd like to see what happens... i'm thinking about ordering the forge soon.

 

[Maxxpwr]

I understand that. I'd still hate to have any sort of issues with the dealer. Either way, the stocker should be going back on tomorrow. If that is the issue, I'll just save the BPV for the point at which I do more upgrades such as ECU and upgrade the turbo.

I may also just try resetting the ECU and letting it relearn as I did when I installed the DP and RP. It is funny, I was getting an intermittent CEL (assumed o2) before and since the BPV, there has been no CEL.

did you not do any sort of trick to do anything to your o2 sensor? if your ecu is stock it sounds like you could be runing lean. Im not sure how exactly it works in the ms3 and I know I never had problems with it in my msp after doing the non-fouler method. but in my evo, my o2 sensor went bad (for absolutely no reason, because I still had stock cats) and my CEL would go on then off. then come back on hours or days later. the car thought I was running ultra lean. so the ecu freaked out and started going into safe mode and poured alot of gas into my motor. noticed a loss of power and rediculous gas economy. It could be something stupid like that, bad o2 sensor throwing off your a/f ratios.

-someone else kick in with more help here. Im just throwing out ideas but am no expert on ms3-ness

 

[ill_eagle94]

The parts I ordered came with something similar to a spark plug non fouler.

 

[Craighjr]

Hey that sounds like the boost cut issue I have. Its like the car bogs right when the turbo comes on full boil. Rig up a boost gauge. Bet your hitting 21 psi. The factory pcm pulls boost when it is at 18psi for over one second (as I was told in my thread) Check my mods all I have over you is a cat back. Im sure the cars are breathing the same betweent the factory 2.5 and aftermarket 3 inchers.

 

[ill_eagle94]

So if it is that, the boost cut defender would help, but is it safe?

Now, it's not like it just cuts it, it is basically like a little hiccup, the power comes right back on, only to be cut again 2-300 RPM later.

Also, note that it did not act up when it was up around 60 degrees today, but once it got to 55 of so this afternoon, it was starting to do it again. It would make sense that I'm getting more airflow from the turbo in the cooler air, thus building more boost.

A couple guys at the track today with DSMs noted that with the 43 degree morning temp they were able to build 21 PSI on stutterbox (launch control) and once the temps came up they were only building 17-18 psi off the line.

 

[Craighjr]

I just bought the Standback to tune the car fully. I don't feel like jerking around with all the manual stuff. I haven't installed it yet, but maybe by the end of the month everything will be in and tuned.

 

[ill_eagle94]

I just bought the Standback to tune the car fully. I don't feel like jerking around with all the manual stuff. I haven't installed it yet, but maybe by the end of the month everything will be in and tuned.

If something were plug and play, I'd be all over it.

 

[ill_eagle94]

So... tossed the stock BPV back in today. Got on it on the highway tonight and no problems whatsoever. It is 47 degrees out and no issues.

57 degrees with the Forge and I was getting hesitation. (huh)

 

[laloosh]

i highly doubt its the forge, your car is just experiencing fuel cut with the fujita intake you have on there.

 

[ill_eagle94]

i highly doubt its the forge, your car is just experiencing fuel cut with the fujita intake you have on there.

Issue is gone with the stock BPV back on although as I said in my drag time thread, it feels like boost tapered off and on in 3rd and 4th on one of my runs. I've had the intake since I had about 500 miles on the car.

 

[laloosh]

Issue is gone with the stock BPV back on although as I said in my drag time thread, it feels like boost tapered off and on in 3rd and 4th on one of my runs. I've had the intake since I had about 500 miles on the car.

yea, but once you add a DP/RP and cold temps with incorrect intake reading you will hit fuel cut. Trust me, its not the BPV, it has noway of causing boost cut, just think about what a bpv does and how it works. The reason why you havnt hit it with the stocker yet is because your lucky, or your stocker is leaking boost.

 

[ill_eagle94]

yea, but once you add a DP/RP and cold temps with incorrect intake reading you will hit fuel cut. Trust me, its not the BPV, it has noway of causing boost cut, just think about what a bpv does and how it works. The reason why you havnt hit it with the stocker yet is because your lucky, or your stocker is leaking boost.

Thats exactly what I think is happening. I think the stocker is leaking. The Forge is holding better and allowing the car to build enough boost to the point where it's seeing too much airflow.

How can I get around it without some sort of engine management?

 

[laloosh]

atp fuel cut defender

 

[ill_eagle94]

atp fuel cut defender

Awesome. Is it safe? Considering I'm not using a boost controller to raise boost.

 

[laloosh]

ive been running it for a couple weeks now on raised boost with no problems