Fuel-cut is driving me insane! HALP!

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Preferio

I break stuff.
Contributor
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2003 Mazdaspeed Protege 1660, 2004 Winning Blue RX8, 2005 Mazda6
Okay, since upping the boost to 10psi (spiking at times to 14psi) I've been hitting fuel cut. I even dialed it down to 8.5psi but will still sometimes hit fuel cut. Weather has been anywhere from 20-40 degrees in the past couple of weeks, but yesterday it was almost 59. Even at 8.5psi I hit fuel cut. I have NO DTC's current or stored in the fault memory. My boost gauge is showing 20hg of vacuum. I have smoke tested my charge piping to make sure I have no leaks. If I do WOT I am guaranteed to hit fuel-cut at about 4,800-5,000 RPM. I am currently running the SSAFC V1 with the "Superstock" map. My other mods are listed below. If anyone has any incite to help me correct this issue, I'd be greatly appreciative.
 
In those temps without a full stand-alone you will hit the cut no matter what you set your boost at. Just use less foot pressure when its cold over night or in the morning. Its all inlet air temp based, not psi. Stand-alone allows you to bypass that feature of our PCM.
 
Even with 60 degree temperatures?

I know when it's 20 degrees out I'm going to have this issue, but when it's 59 degrees out? Right now it's 66 degrees. I'm going to go jump in my car and drive down the ******' road right now to see if I hit fuel cut.
 
Only other thing that would cause it besides low temps is , a) running to much boost or b) boost leak... If you can put your car back down to stock boost levels and see if you have that problem still
 
StealthWyvern said:
Only other thing that would cause it besides low temps is , a) running to much boost or b) boost leak... If you can put your car back down to stock boost levels and see if you have that problem still
Click to expand...
Yeah, boost leak- smoke tested the charge piping 5 times. None found. 10spi shouldn't be "too much" boost. I dialed it down to 8.5 and still hit fuel-cut.
 
Preferio said:
Yeah, boost leak- smoke tested the charge piping 5 times. None found. 10spi shouldn't be "too much" boost. I dialed it down to 8.5 and still hit fuel-cut.
Click to expand...

The guy down the street from me has a 100% stock MSP and hits fuel cut on cold days...boosting 6-7lbs.. So hitting fuel cut on 8.5 doesnt surprise me.. I've hit it at 8 as well.
 
Check your charge piping with a boost leak tester. You may have a leak that only opens under boost.
 
I think every car might be differnt but i hit 8.5psi and its in the low 40s and no fuel cut i think its the backpressure in my exhuast that saves me i could see if you have larger exhaust system less back pressure that your going to spike your maf and hit fuel cut. Does that make sense?
 
Yeah... Well I'm getting a P0103: MAF circuit high input right now. Maybe a flaky MAF, or (probably) my SSAFC connections.

I don't think I'm getting a boost leak, but I did find a nice tear/hole in the elbow to the throttle body, but it's where it would be against the throttle body... So that may be it. I'm going to slide it further down the throttle body and move the clamp further up.
 
You shouldn't hit fuel cut if you have ssafc. It's also a fcd. I run 12-14 all winter no problems in Chicago.
 
slo03.5msp said:
You shouldn't hit fuel cut if you have ssafc. It's also a fcd. I run 12-14 all winter no problems in Chicago.
Click to expand...
My thoughts exactly, but everyone else seems to want to disagree with me and swear I'm "overloading the MAF". The SSAFC is wired into the MAF circuit and uses a vacuum signal to modify the signal from the MAF to the ECM thus bypassing the MAF reading... At least that's my thought.
 
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With the SSAFC, there will be no fuel cut? Would be nice, instead of a fuel cut defender.
 
doesn't mean it still can't happen. I have had the SSAFC in my car for a couple of years now and I still get fuel cut every now and then...more often now since it has been cool out. I completely agree with the MAF explanation since it is only a piggyback, it isn't perfect. It is definitely an improvement, but with anything there is always room for more improvement.
 
I got my wideband problem fixed, so tomorrow I'm going to start "tuning". I am hotting fuel-cut only after I've been in boost for a long period of time.... like getting on to the interstate and doing so at WOT. This is so damn discouraging!
 
I wish I had all my data logs. It's flooding toomuch fuel tune it into the high 11's to mid 12's and it will go.
 
slo03.5msp said:
I wish I had all my data logs. It's flooding toomuch fuel tune it into the high 11's to mid 12's and it will go.
Click to expand...
My goal AFRs are 11.4-11.7... Adam (MSP2k3) sold his MSP and has a set of 440's he wants to sell me. I might do it.
 
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