fuel cut

[TheStuartKid]

Just finished installing my cx racing FMIC and at first everything was going fine but now i am getting a fuel cut when im doing WOT pulls in 3rd and 4th gear. It doesn't happen as soon as i go into boost it happens when im around 4000 rpms. I have upgraded autotech fuel pump internals and never had this problem until i installed the intercooler. Any suggestions? I am also around the time for new spark plugs... Could that be it?

 

[MSMS3]

Pull and regap the plugs to .028". My guess is that they have opened up.

Could you please include your current mods in your signature or include them in your posts? Knowing that make a huge difference in troubleshooting problems.

 

[javis]

Did you change the Map?

 

[TheStuartKid]

Sorry about the signature i could never figure out how to do it but now its there. and yes i changed the map when installed the intercooler to stage 2 +intake+TIH+Ic and it just now started giving me trouble. Im going to change my spark plugs because its about time, what is your recommendation?

 

[chimmike]

If you don't have upgraded fuel pump internals that's your problem. Do NOT run stage 2 maps without upgraded fuel pump. Cobb even says this.

 

[javis]

Post all your mods.
Spark plugs have nothing to do with the fuel cut, but you could use 1 step colder.

 

[TheStuartKid]

No i do have internals and they have been working fine for me. I also just threw a P0401 CEL ( exhaust gas recirculation flow insufficient detected) if that is anything relevant..

 

[javis]

Post your mods. We can't help when whe don't know what you've done to your car.

 

[etipp98]

Could be overboosting... how do you know it is fuel cut?

 

[TheStuartKid]

I posted my mods in my signature, are they not showing up? Im not positive its fuel cut, it was just my best guess... i never thought about over boosting. Should i try re flashing the same map or a different one?

 

[etipp98]

Why don't you take some wot logs and post them up? We need to see them if you want an answer.

 

[chimmike]

I guarantee it's fuel cut. And how do I know this? cooler temps plus better tmic=cooler, denser air.

stage 2 maps command more fuel pressure, hence why hpfp internals are required.
Get internals or blow. your choice.

People seem to not understand: there is a methodology to modding the MZR that is different from port injection cars. In a way, it's better up to 400whp, because all you need to do is upgrade the fuel pump internals instead of buying all new injectors and a new in-tank pump. However, once that ~400whp mark is hit (usually 380whp ish on pump gas or e85), there's just no more flow to be had (when using hpfp internals and commanding no more than 1750-1800psi, lest you want relief valve issues)

 

[etipp98]

he has fp internals...

I guarantee it's fuel cut. And how do I know this? cooler temps plus better tmic=cooler, denser air.

stage 2 maps command more fuel pressure, hence why hpfp internals are required.
Get internals or blow. your choice.

People seem to not understand: there is a methodology to modding the MZR that is different from port injection cars. In a way, it's better up to 400whp, because all you need to do is upgrade the fuel pump internals instead of buying all new injectors and a new in-tank pump. However, once that ~400whp mark is hit (usually 380whp ish on pump gas or e85), there's just no more flow to be had (when using hpfp internals and commanding no more than 1750-1800psi, lest you want relief valve issues)

 

[chimmike]

fail on me.

could be load cut.

 

[TheStuartKid]

i did a few logs earlier and i will post them tonight, but my guess is i just need a dyno tune. It is saying i should peak 19 pounds and hold 17.5 for the map I'm on but i am peaking 22 pounds and holding 19.. is that load cut?

 

[TheStuartKid]

Alright i did 2 logs and i tried uploading them and its saying they are invalid files, can somebody help me out on what to do so i can post these logs for you all to see??

 

[704_mazdaguy]

Post all your mods.
Spark plugs have nothing to do with the fuel cut, but you could use 1 step colder.

wrong, the "fuel cut" could be the car misfiring, from having incorrect gap on the spark plugs.
Never rule anything out.

 

[chimmike]

it's possible. You don't need a dyno tune, nobody in your area knows these motors (which is VERY important. Don't let any ol' shop tell you they can tune it.)
find an e-tuner on msf.org.

 

[TheStuartKid]

Well im hoping its that then because i have the NGK one step colder plugs in the mail right now. I guess ill let you guys know how my car runs when i get those in.

 

[MSMS3]

Those NGK one step colder plugs #6510 (assuming you got the Iridium ones) are great and work well with the mods you have. I run them. But, you must regap them. They come in the box gapped very big (.044" IIRC), and need to be gapped down to .028". Some would say go down to .026. I haven't had a need to go quite that tight.

I think you ought to check the gap on your existing plugs now. This car is hard on plugs, especially if you are running higher than stock boost level, and on my car the plugs seem to last only about 25,000 miles. I would not be surprised to hear that they have opened up.

Try posting those logs in .xls format (Microsoft Excel). I think this site will accept that file extension. We can then look at them in Excel or convert them to .csv format, which is more universal and look at them. If the "cut" is happening at around 4,000 rpm and then clears up once you get past that, this is a strong indicator that you are getting boost induced spark blow out.

Also, I think that if you are "seeing" 22 psi you may be overboosting to an even higher boost. I think that the sensor runs out of upper range at about 22.5 psi and that the ECU will either load cut or fuel cut at that point. The sensor just keeps showing 22 psi, even though boost could be higher.

I think you may be in over your head and need a professional tuner to sort things out. An OTC AP Stage 2 map would probably be a starting point, but would need to be "tweaked" by someone who really knows this engine well, like one of the highly respected custom tuners that hang out on the MSF board. They could analyze your datalogs and AP map and make custom adjustments in the map to maximize performance for your particular mods. That can be done via email exchanges and would be better than getting some local dyno tuner that does not understand these engines. I agree completely with Chimmike on this.