Possible Fuel Cut Solutions

[AFaceInTheCrowd]

ok well i've come across a couple of ways to maybe eliminate the all mighty dreaded barrier, the fuel cut. I'm gettin this from old Corolla turbo research i had leftover from my failed turbo endevour so it might not work for us.

First is the Split Second VC2. it edits the MAP signal to eliminate the fuel cut.

the second is a diagram that i have. this diagram is, what i'm told, a DIY FCD (Fuel Cut Defender). RX-KEVIN, this is for you.

i hope that one solution works. that would give us more room to play.

 

[melicha8]

Well first off we don't have a MAP sensor the Protege uses a MAF. That is all I can add. Don't know too much about the fuel system

 

[AFaceInTheCrowd]

ok, i'll be more specific then.
the VC2 also edits the MAF signal. there is a thread regarding a MAP on MSPs somewhere.


......Underworld? you raver... haha i listen to them too

 

[KYREDP5]

3rd gen Proteges do have an MAP sensor.

http://www.protege5.com/vbb225/showthread.php?s=&threadid=19238&highlight=MAP+Sensor

the egr boost sensor is nothing more than a fancy name for a MAP sensor... all it does is measure manifold pressure... it exists on the non-turbo pros as well as the msp

from what I heard, the MAF is used below 2000rpm or so and is switched to "standby" backup mode after that and the MAP sensor is used

I trust that Edwin knows what he's talking about.

 

[funnylittlman]

quote:
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Originally posted by TheMAN
from what I heard, the MAF is used below 2000rpm or so and is switched to "standby" backup mode after that and the MAP sensor is used
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This could also help w/ our ECU stumbling issue

 

[xsivspd]

The Mazdaspeed has a MAP sensor, not--MAF.

"Hi Phillip,
Sorry for the delay getting back to you. We do carry the TURBOSMART Pneumatic Fuel Cut Defender (FG-FCD-001) for $78.95.
We have your item in stock and it will work with your Mazdaspeed Protege.
Thanks and Best Regards,
Ron Meyers
SernaSport, Inc.
ronmeyers@sernasport.com
http://www.sernasport.com
Toll Free 1-877-777-8005"

 

[ForceFed]

not to sound like an ass but ,the last time I checked........I have a nice restrictive MAF in my MSP!YO Xsivspd,What do you think that is right behind the stock airbox???It's definately not the world's largest air temp sensor!

 

[KYREDP5]

The MSPs have both a MAF and a MAP. As I quoted earlier.

the MAF is used below 2000rpm or so and is switched to "standby" backup mode after that and the MAP sensor is used

 

[xsivspd]

What I am saying is that Ron Meyers at sernasport.com has informed me, and has confirmed/researched this himself,
that the Fuel cut for the MSP is monitored and controlled by the MAP, not the MAF.

 

[ForceFed]

bump!

Can anyone confirm or deny this? If the MSP has a map sensor the fuel cut might be monitored by this?HMMM???????
*BREAKS OUT THE 'OL CHALKBOARD AND GOES TO WORK!*

 

[kwiktsi]

I was informed by a Mazda performance shop that the RX-7 uses a MAF for air counts and uses the MAP for the fuel cut. I have also heard that the MSP uses the MAP sensor only for EGR.. I will ask around some more and look into it- if it is true about using the MAP for the fuel cut, then you can easily bleed some of the pressure from that line to prevent it from seeing full boost. However, I have noticed that air temp makes a difference in when it will fuel cut also which leads me to believe it is the MAF readings that cause it- colder air is denser, therefore the ECU sees more of it at the same intake flow.
Joe

 

[xsivspd]

I have purchased the pneumatic Fuel Cut Defender from Turbosmart, and will be installing it when it arrives in the mail in about 1-2 weeks. Our MSP have a MAP sensor that controls the fuel cut - it is located top left area in the engine bay. Will let everyone know the results when installed.
I agree to what JoeP is saying and what now my mechanic at westowne mazda in Toronto is telling to be true.

 

[perfworks]

3rd gen Proteges do have an MAP sensor.

http://www.protege5.com/vbb225/showthread.php?s=&threadid=19238&highlight=MAP+Sensor







I trust that Edwin knows what he's talking about.

This is not completely correct.
There is NO MAP SENSOR in the protege. PERIOD. Sorry to be harsh but it is the truth.
We and all proteges have an EGR boost sensor AKA barometric pressure sensor. They are not the same as MAP sensors. It is limited in its responsabilitys. It will give a signal to the ecu to activate the boost solenoid to the EGR. The MAF is the primary source used to control A/F ratio. Now if the baro sensor gets an eroneous signal ( abnormal pressure surge thru the vacuum line)
it MAY "see" boost and create a problem. I dont know yet, BUT we are making several efforts to see the operation of the system first hand this week when we boost the pro5 and tune it with the module. We will datalog the operation of the baro and see what gives under all load , throttle angle and rpm conditions. It has the same set up and will confirm along with joe (kwicktsi) the ACTUALL operation of the baro and MAF sensors/meters. All of the speculation will come to rest soon.
As far as edwin is concerned, he is a very intelligent individual and am not doubting his knowledge but i have seen and heard too many myths and will try to clear everything up in no time.
This is in no way saying that the baro sensor does not control or help in the actual fuel deletion problem at a certain airflow or boost level .
What i CAN say is that after speaking with joe there are several issues with the stock MSP ecu and it is not as advanced as previously thought. We will be working together with Joe and come out with a piggy back to solve all those problems in the next two weeks.
Ill keep you guys posted.

 

[kwiktsi]

I'll know tomorrow if the weather is decent whether or not the baro (map) sensor has anything to do with fuel cut. My gut is saying it is MAF readings, but I will know more after a couple of tests.. If it is MAF- there are a few ways to go around it- AFC (old style is best because you can get them cheap and they will do nothing for WOT tuning anyway), possibly an HKS FCD or creating an air leak after the MAF (like the bov return fitting with a K&N and dumped BOV for those running aftermarket BOV's) but the latter is not a precise means of doing it.

Nick (perfworks) and I will have more solid answers in the next couple of weeks.

I agree whole heartedly- all the speculation and assumptions need to end and fact needs to be learned .
Joe

 

[kwiktsi]

OK, as suspected- the MAP/EGR sensor has NOTHING to do with fuel cut or mapping. It is air flow based. For those that don't believe it or feel the MAP has any control of the mapping above certain RPM's or whaterver- unplug the hose from it and tell me how the car runs .. The same!! same fuel cut, etc... Doesn't even throw a CEL. I'm sure it would after a while, but this was just a few minutes to test it..

Fuel cut is going to have to be addressed via the MAF signal as I have said all along .
Joe

 

[ARunto]

So can a HKS FCD be used to get rid of the fuel cut?

 

[kwiktsi]

I don't see why not, but I have not used one and you would need to know what posistion to set the dial to, I don't think our cars are in the manual. I was just going to go with the original knob-style AFC so I can pull some of the excessive mid range fuel also.
Joe