Have you ever done something to fix fuel cut and it DIDN'T work?

[dizwhoadayjohn]

PTP hpfp ftw!

 

[Knox Joe]

Where you running 440's by any chance cause I'm starting think that for those who have not fuel cut in the winter are using 440's. Wondering if that might have anything to do with it. All I know is that my FTC with a built in map of 21psi still caused me to cut.

Actually, yes. But that has nothing to do with it. The signal from the MAF has nothing to do with fuel. If the MAF signal goes above 4.7v it will hit fuel cut regardless of a/f ratios, or injector size. The MAF reads intake air, and the MAF has no way of knowing what injectors or how much fuel you are using, so how would that make a difference?

 

[Jaysanooch]

Actually, yes. But that has nothing to do with it. The signal from the MAF has nothing to do with fuel. If the MAF signal goes above 4.7v it will hit fuel cut regardless of a/f ratios, or injector size. The MAF reads intake air, and the MAF has no way of knowing what injectors or how much fuel you are using, so how would that make a difference?

The reason I mentioned this though is because I noticed with stock injectors...if you ask the AFC to add fuel...well for me anyway it will fuel cut even if the cel value is just 10.1.

Also, I've read that if your tuning with a P5 ECU on stock injectors...if you ask the AFC to add fuel you max out the MAF. But if you use 440's it seems to be ok.

This is why I started relating injectors with maxing out the MAF.

 

[Wagonbacker9]

The reason I mentioned this though is because I noticed with stock injectors...if you ask the AFC to add fuel...well for me anyway it will fuel cut even if the cel value is just 10.1.

Also, I've read that if your tuning with a P5 ECU on stock injectors...if you ask the AFC to add fuel you max out the MAF. But if you use 440's it seems to be ok.

This is why I started relating injectors with maxing out the MAF.

with bigger injectors, (like I said already) you give the ECU a lower MAF voltage, because a shorter injector pulse on larger injectors delivers the fuel you need. (higher rate, shorter duration)... this eliminates fuel cut almost absolutely.

 

[Knox Joe]

with bigger injectors, (like I said already) you give the ECU a lower MAF voltage, because a shorter injector pulse on larger injectors delivers the fuel you need. (higher rate, shorter duration)... this eliminates fuel cut almost absolutely.

I don't believe that is correct. I have discussed this with some more knowledgeable people before coming back to comment on this, and they all agree with me. The MAF just reads air volume intake. The size of the injector has no effect on this at all.

A MAF works by heating a wire with an electric current that is suspended in the engine’s air stream, like a toaster wire. The wire's electrical resistance increases as the wire’s temperature increases, which limits electrical current flowing through the circuit. When air flows past the wire, the wire cools, decreasing its resistance, which in turn allows more current to flow through the circuit. As more current flows, the wire’s temperature increases until the resistance reaches equilibrium again. The amount of current required to maintain the wire’s temperature is directly proportional to the mass of air flowing past the wire. The integrated electronic circuit converts the measurement of current into a voltage signal which is sent to the ECU.

 

[SeR_Cyclops]

And there ya have it folks! lol but really that is neat i never knew how they worked.

 

[CHIQLES]

Buurrnn.lol

 

[CHIQLES]

But realy then should we turn down the boost so that the element doesnt go past a point of fuel cut off unless you have a stand alone and then you can pretty much bypass that system correct?

 

[joem.]

I have a unichip and have had no problems with fuel cut
..the only time I did was when I had a faulty maf.. It got some dirt or something in there and broke off the little metal thing .. Replaced it and no problems .. I run 10psi all seasons..

 

[Outlawstar98]

Both of you get a room and stop compairing dick size..... Shake hands and stop fighting.

 

[GiJoe]

Well, I just had a good laugh for the last couple pages.

 

[Wagonbacker9]

outlaw, you deleted the post that explicitly explains the function of the SSAFC in avoiding fuel cut... can you put that back up please?

 

[Outlawstar98]

outlaw, you deleted the post that explicitly explains the function of the SSAFC in avoiding fuel cut... can you put that back up please?

I went though the posts I deleted, alot of them contain info about the SSAFC, but to me, to much negativity, Please rewrite. (from what i read though it wont be that hard to rewrite.)

But next time you feel like having a contest on who is right, go to PM's then post the outcome on here.. Don't fill these topics with useless slander and fighting.

Thanks.

Outlaw.

 

[Wagonbacker9]

summary then.... i can live with that.

a MAF clamp, simply stops the MAF from outputing voltage to the ECU higher than the 4.7 volts it would normally fuel cut at. This can be dangerous if you overboost and the engine actually NEEDS that extra fuel in order not to lean out. The MSP has a VERY conservative (rich) tune... and a pretty wide safety margin on fuel cut. If you're willing to risk it... be my guest, but don't come crying when you join the zoom zoom boom club, you do so at your own risk.

putting an SSAFC on maniuplates the voltage seen by the ECU (for clarification: NOT the actual voltage produced by the MAF). even with the SSAFC in it is possible to hit fuel cut because you have a limited range that you can tune to, and can still end up with a tune that forces you to deliver a MAF signal to the ECU which is higher than the 4.7v fuel cut, in an attempt to deliver enough fuel to tune in the proper AFR you are trying to maintain.

Going up to bigger injectors will cause you to tune the SSAFC MAF output to a lower voltage (which is an then input to the ECU) given an equivalent voltage for that would be shown to the ECU for stock injectors when trying to achieve the same AFR under the same conditions otherwise. This in turn makes the ECU give a shorter injector pulse, and since the injectors flow more, you are able to deliver more fuel before hitting fuel cut (potentially the same % gain in fuel as the % difference in flow rate between stock and your larger injectors, if both were run to 100% duty cycle)... in all likelyhood, you could deliver much more fuel than you would need to under any circumstances where a piggyback would be an appropriate EMS.

as outlaw stated, arguments and clarifications may be directed to my PM box.

 

[SeR_Cyclops]

Wow, I read all those useless post and I just now understand what you all were saying. So for those that did read those post. Joe is right by saying that larger injectors have nothing to do with fuel cut but wagon is saying that if you have larger injectors with the AFC then you can lower the signal the ECU sees and thus eliminating fuel cut. Correct?

 

[937protege]

ok so im not trying to thread jack... but i too am experiencing a similar issue. i have a fmic, hard pipes, exhaust, aem wideband o2, intake, and a t25r. when i hit 9-10 lbs i hit fuel cut. im not looking to spend a whole lot to get this fixed. i saw the fcd for 80 bucks. im not looking to run any more boost im just looking to be able to drive the car the way it is with out fuel cut. is the fcd a good choice for the price and the mods i have? and not planning to do anything other engine mods?

 

[SeR_Cyclops]

Its the only option you have but lowering the boost if you are not doing any other mods. Also I wouldnt run 10psi on the stock block without engine management.

 

[937protege]

ok. i just got the car and it doesnt have a boost controller that i was told about or that i have seen. and its the factory wga. what is the factory boost? and my afr's are good through out evena t 9 lbs...? still shouldnt be that high w out em?

 

[satyr36]

"shouldnt" be a problem. but you can get a problem at stock (6lbs) of boost. everyones car is different. and if you have the stock WGA + no MBC then 9lbs of boost isnt possible unless something (wga) is failing.

 

[Wagonbacker9]

"shouldnt" be a problem. but you can get a problem at stock (6lbs) of boost. everyones car is different. and if you have the stock WGA + no MBC then 9lbs of boost isnt possible unless something (wga) is failing.

yeah, I'd bet you have a WGA leak. I currently do as well, as I can boost 10 psi with no MBC... oops.