Fuel cut out at max boost

[msp14]

Okay my Msp has a problem where when it reaches Mac boost it feels like I hit a brick wall. It kinda feels like its a fuel cut but I don't know what else to check. Whenever I get into the throttle a lot an speed up quick it don do it as bad but when I ease into te boost it jerks terribly. I've gotten a vacuum block and redid all my hoses and that wasn't it. I've replaced the fpr ad that wasn't it either. Also replaced the maf sensor and still not any better. Any suggestions on what it might be?

 

[jbrewer4639]

it soounds like fuel cut. you can buy a split second air fuel controller(399$ new) to recalibrate your fuel/air mixture that is the most common fix.

 

[msp14]

Yea I've heard that to but my buddie who's got a Msp said that it should be as violent of a fuel cut like mine is, it seriously feels like I hit a brick wall when it happens. I might just invest in a split second anyways though

 

[SCMP3]

You Def need it. I really do think its fuel cut. It's insanely violent. Also he has the cel for the fpr sensor or whatever. The po of his car had some crazy vacuum setup. It's all back the way it should be now

 

[_Chris]

Mine does this also. Ive got FMCI, CAI, DP but stock exhaust. I hit like 6-7psi and it just hits the violent fuel cut. I can normally run 1st gear out but it will sometimes set the CEL for the MAF sensor. Then will go off if I drive it normal. I can hear the turbo more than I think I should, so i'm going to go over all the hose clamps and silicone and make sure they are all good. I don't see why I should be hitting fuel cut running 7psi. Ive just been to busy with other stuff to get to work on the car as much as I want to.

 

[msp14]

thats the same problem im having! the previous owner had a gredy boost controller hooked up but it was still running 7 psi and I un hooked all of that and it didnt feul cut for a while then it started again but just not as violent.

 

[b_dues]

It doesn't matter how much boost you're running if your a/f mixture is way off. Your mixture can fluctuate through rpms also so get a wide band and an SSAFC. You can pick both of those up in the classifieds for a good price. This is an extremely common problem with MSP's, especially if the car has been tuned or "played" with in the past.

 

[Spiced MSP]

looks like everyone already said it...SSAFC is your answer

 

[_Chris]

This?

 

[Spiced MSP]

programmable signal calibrator from them. They make one preloaded for our cars though. I think it is the PSC1 or something like that. Make sure it has the extra orange wires for datalogging capabilities.
Protege Garage sells the SSAFC that is loaded for our cars. The also sell the one that controls timing as well.

 

[hornsfan10609]

I'm not sure you can still get an SSFTC new, they may still have the SSAFCs though, I bought one used and am extremely happy with the way the car runs.

 

[jdwk]

The car shouldn't fuel cut (it's actually spark cut guys) at stock boost levels unless it's running very rich. Do you have a boost gauge and what are you seeing?

My car did exactly what you are describing when my wastegate actuator went bad. Just pull the vacuum hose leading to the WGA off the block with the car off and blow into it. It should be like blowing into a wall, if you can blow through it, you need to replace the WGA. My stock one was replaced once under warranty, and I replaced that one shortly after my warranty ended with an ATP.

I also have caused my car to cut spark many times when tuning with the AEM FIC. Even after putting the AEM in bypass mode (stock), I was still able to hit cut because my fuel trims had gone off the chart due to my O2 manipulation. It occurs anytime the PCM drives 100% duty cycle on the injectors. A stock car rarely needs over 80%, but fuel trims can easily add 20%.

I don't think you need to go investing in a piggyback to solve this problem unless you want to go down that road for other reasons as well.

If the wastegate is good, I would find a friend with an OBDII reader and check your fuel trims. Autozone may be able to read them for you as well, but I think their scanner only reads codes, not parameters. If they are very high, as in the +20 range, it can be a couple of reasons, but most likely a bad O2 or exhaust leak. You can also reset the PCM and the problem will go away temporarily.

Try the WGA first and report back.

 

[msp14]

Ok the WGA is fine, felt like I was blowing into a brick wall like you mentioned. A couple of codes came up on the car though, the fuel pressure regulator control unit and the bank 1 02 sensor. The check engine light will go off sometimes but it stays on for majority of the time. I replaced the o2 sensor that was in my exhaust so I'm guessing the one that is bad is in the exhaust manifold so that is on my list to change next. And I'm not sure what I need to change off of my fuel pressure regulator because I already changed the part that come strait off the fuel rail and it's still flashing the code.

 

[Preferio]

looks like everyone already said it...SSAFC is your answer

How can you say the SSAFC is going to correct his problem, when you said the EXACT opposite in my thread? LOL

 

[Spiced MSP]

because for most people, it does fix the problem if everything else has been tested and there is nothing else mechanically wrong with the car. If the car has no other issues and you already have the SSAFC installed, have tried multiple maps to include tuning to your specific setup, then other contributing factors like weather or the MAF issue explained in your thread could be the culprit. But, we all know this is only a piggyback not a 100% tuning solution. It's not going to be perfect all the time. Im on my lunch break right now and on my way to get something to eat, I experienced a little hesitation that the SSAFC is claimed to eliminate. You just have to work with it, try tuning it out. The constantly changing weather here in TX doesn't help me at all. But that could be a factor in this situation