Fuel Cut
 

I Have A 2003 Mazda Speed Turbo. I Just Did 3 Inch Exhaust And Upped The Boost And Now I Get Fuel Cut. Does Anybody Know How To Get Rid Of The Fuel Cut? Let Me Know Please

Get a boost controller and turn down your boost.

After you're done that go see a shop and get a fuel controller such as an S-AFC, which in turn will help you tune out fuel cut.

Have fun...

You can get a fuel cut defensor that will clamp the signal. But then you have no fuel cut, so that can be dangerous. Other alternatives are finding an air flow sensor that will let in more air, but if you do that you will need to compensate by adding more fuel. In my case I can use a lexus v8 air flow sensor that will let in 25% more air, and upgrade to 550cc injectors which is 25% increase over my stock ones, so it works perfectly.

Another option is making a vacuum leak after the air flow sensor to let some extra air in, but that is not safe. So don't do that...

Another option is using a GM MAF-T (alot of DSM guys use this, as well as mk3 supras).

Or just go standalone :)

Whatever you do, fuel cut (technically it is spark cut) is there for a reason so you dont run lean. If you are upping the boost, make sure you have enough fuel.

^ Theres fuel cut AND spark cut. And *TECHNICALLY*, it doesn't completely cut the spark off (that would send unburnt fuel throught the expensive catalytic converters), it just retards it.

Theres a reason Mazda put a fuel cut in your ECU. With my Mazda, if you unplug the fuel cut and boost it about 13psi, you're just baking the inside of the engine because the stock ECU doesn't have the fuel mapping for higher boost. Don't try and trick it by bypassing it or anything... you'll just make things worse. Get a fuel controller like someone suggested before.

Buy an adjustable fuel pressure regulator and turn your base fuel pressure up. Then buy a wideband, then an air/fuel controller and learn how to tune.

^ Not advisable for dumb people.

Hey lets buy a brand new $30,000 car and then the warranty by modifying it!

Mazda doesn't build their turbo cars like they used to. My turbo engine is 85% different internally then the exact same engine in NA form... its stronger, has better cams, etc etc etc. The MSP engine is the same engine as the basic Protege, except it has a turbo. As far as I know, they didn't really fortify the internals like they should have. I wouldn't boost it *that* much past the stock boost levels, just to be safe.

which model and year lexus does that vaf come from?

Lexus Ls400 I believe. Not sure on the year.

just get a new maf housing ... 3"inch


or convert to map ;)

You can't just magically upgrade to a bigger MAF and expect everything to run perfectly.

If you don't understand why, then thats too bad because I don't want to explain it.

ok so all you guys are saying is that there is nothing i can buy. as in a fuel cut eliminator. i don't want to over boost it but i want to up the boost a bit to 7 psi instead of 4.

im sure your stock boost is probably around 9-11 psi not 4

You can buy an FCD (fuel cut defensor). It lames terms, it will eliminate fuel/spark cut off.

meh, all this electronic mumbo jumbo...

on my Volvo fuel cut was nothing more than a vacuum line running to a boost operated switch.....at certain boost level the switch clicked and BAM, ECU cuz the spark.....its like hitting a wall....not a pretty feeling....

wanna get rid of the boost cut off? u could either plug up the vacuum line and not have any protection or adjust the switch to a higher setting, VIA A SCREWDRIVER!!!

ya...pretty simple...
stock boost was 7, the limiter kicked in at 15, by the end i was running 22 psi, with fuel mods ofcourse...

^ Not all cars are the same. Mine is controlled by Karman Herz. When the AFM sees a certain number it thinks DANGER and then you get fuel cut. There are no vacuum lines to change to make it go away. Ways of raising it are adjusting your base fuel pressure and then tuning accordingly with an AFC.

Depending on how fuel cut is triggered and controlled by your ecu, you either need an FCD, different AFM, shitload of piggy backs, or go standalone.