Another ? about Fuel cut defencers!!!

[Eclipsed]

Ok, it's come to the point where I need to either get a TMO ecu for aoubt 500 bucks. Or get an HKS fuel cut defencer for about 114. I would much rather save myself some money and get the FCD. It's so damn hard to log wiht this damn fuel cut. It's so sparadic and weather affects it so much. I need some sites that can help me install the FCD and also some sites that sell them. Thanks alot.

 

[nine5raptor]

you need to address the issue of why you are getting fuel cut instead of putting on an FCD. You will simply blow your motor.

Fuel cut is a warning system, letting you know you are out of injector.

 

[LandoAWD]

Originally posted by nine5raptor
you need to address the issue of why you are getting fuel cut instead of putting on an FCD. You will simply blow your motor.

Fuel cut is a warning system, letting you know you are out of injector.

You could just upgrade the MAF. Blaha or a 2g are cheap and easy.

 

[brads]

You already have an AFC. Fuel cut defencers work by telling the ECU the engine is taking in less air, alot like the AFC. If you cant lean it out enough with the AFC, either get bigger injectors, so you can turn your AFC down more, or get an ECU with the fuel cut removed. I wouldnt waste time with the TMO one though. For a little more than the TMO, you could get a lot better functionality with the DSMLink, you could probably make up the cost difference by selling your AFC and logger, and still be much better off in the long run.

Brad

Originally posted by Eclipsed
Ok, it's come to the point where I need to either get a TMO ecu for aoubt 500 bucks. Or get an HKS fuel cut defencer for about 114. I would much rather save myself some money and get the FCD. It's so damn hard to log wiht this damn fuel cut. It's so sparadic and weather affects it so much. I need some sites that can help me install the FCD and also some sites that sell them. Thanks alot.

 

[LandoAWD]

Damn, I just looked at what he drives. I guess a 2g MAF is kinda redundant. Check out the LT1/LS1 Translator thread.....cheaper still, than going for a TMO modded chip.

 

[Eclipsed]

Originally posted by brads
You already have an AFC. Fuel cut defencers work by telling the ECU the engine is taking in less air, alot like the AFC. If you cant lean it out enough with the AFC, either get bigger injectors, so you can turn your AFC down more, or get an ECU with the fuel cut removed. I wouldnt waste time with the TMO one though. For a little more than the TMO, you could get a lot better functionality with the DSMLink, you could probably make up the cost difference by selling your AFC and logger, and still be much better off in the long run.

Brad

The main reason I want the FCD is becasue I cant log wiht this damn fuel cut. If I lean my SAFC out more I still cut it. My percents for my hi setting are aobut negative 43 at 5k. So its not needing bigger injectors. I just cant log at all. If I had the FCD I'll get mroe accurate readings. Ive tried leaning it out and my EGT's go way to high and I lose a lot of power so whats the point of going leaner? I just want no more cut!

 

[brads]

How do you think the fuel cut defencer works? Do you think there is a fuel cut sensor? No, there isnt. The ECU cuts fuel when the amount of air it sees coming in reaches a certain level. So the FCDs work by telling the ECU there is less air coming in than there really is. Like an AFC. Like my previous post said.

Understanding how that works, now let me explain to you why you would need to still get bigger injectors with the FCD. If you are running the AFC and you have leaned it out as much as you can with the current injectors, then leaning it out anymore is bad correct? BUT, in order to prevent fuel cut, you WANT the ECU to believe its seeing less air, which would result in leaning it out even more with the injectors you have now. BUT if you were to say get 20% larger injectors, you could tell the ECU it was getting 20% less airflow, and still get the same amount of fuel injected. That would push the point of fuel cut a good bit higher, and you might not hit it then. Do you now see why you would need bigger injectors?

If you just want no more fuel cut, get the ECU upgrade. Then you dont have to worry about injector sizing etc. Any other fuel cut defencer will result in having to potentially resize your injectors, or if you want to go the cheap route, you could up the fuel pressure instead of changing injectors. Either way, it would be a workaround that fools the ECU and may only work for so long, while an ECU mod would fix the problem.

With a -43% settting, you must be making a lot of power to still hit fuel cut like that. I hope thats on some sort of race gas with your 550s.

Brad

Originally posted by Eclipsed


The main reason I want the FCD is becasue I cant log wiht this damn fuel cut. If I lean my SAFC out more I still cut it. My percents for my hi setting are aobut negative 43 at 5k. So its not needing bigger injectors. I just cant log at all. If I had the FCD I'll get mroe accurate readings. Ive tried leaning it out and my EGT's go way to high and I lose a lot of power so whats the point of going leaner? I just want no more cut!

 

[LandoAWD]

Originally posted by brads
How do you think the fuel cut defencer works? Do you think there is a fuel cut sensor? No, there isnt. The ECU cuts fuel when the amount of air it sees coming in reaches a certain level. So the FCDs work by telling the ECU there is less air coming in than there really is. Like an AFC. Like my previous post said.

Understanding how that works, now let me explain to you why you would need to still get bigger injectors with the FCD. If you are running the AFC and you have leaned it out as much as you can with the current injectors, then leaning it out anymore is bad correct? BUT, in order to prevent fuel cut, you WANT the ECU to believe its seeing less air, which would result in leaning it out even more with the injectors you have now. BUT if you were to say get 20% larger injectors, you could tell the ECU it was getting 20% less airflow, and still get the same amount of fuel injected. That would push the point of fuel cut a good bit higher, and you might not hit it then. Do you now see why you would need bigger injectors?

If you just want no more fuel cut, get the ECU upgrade. Then you dont have to worry about injector sizing etc. Any other fuel cut defencer will result in having to potentially resize your injectors, or if you want to go the cheap route, you could up the fuel pressure instead of changing injectors. Either way, it would be a workaround that fools the ECU and may only work for so long, while an ECU mod would fix the problem.

With a -43% settting, you must be making a lot of power to still hit fuel cut like that. I hope thats on some sort of race gas with your 550s.

Brad

Ummmm...43 is WAAAAAAAY lean. 17 or 18 in the negative is what you need to have in order to compensate for 550s.

 

[Eclipsed]

How is that too lean? I am only at 13 psi now and I cant bring it up or I hit cut more. I am confused. Maybe you dont understand me. I try to log and becus of fuel cut I cant get decent readings. I understand that I will still need to tune. Im not a noob. I jsut cant tune it right becasue I keep getting crappy readings becaseu of fuel cut. I understand that the safc also tricks the ECU into tihnking less air is going through. I just tihnk taht this fuel cut I'm hitting is stopping me from getting good enough readings to tune around fuel cut. I went to AMS which is a great DSM place and he helped to set my SAFC so there is no way I'm running to lean. They are an incredibly reputable shop. I jsut cant tune myself becasue I dont want to spend money doing it and I cant get good enough readings to do it myself. All I want is a link to an FCD and some hlep on how to install it. All I asked.

 

[nine5raptor]

set your afc much richer and see what happens. If you are fuel cutting on 13 psi with it that lean, you have other issues.

 

[LandoAWD]

Agreed..you shouldn't cut at 13psi. Try a setting around -15 or -17 across the board for low and tell us what you find including AF ratio, and timing.

Originally posted by Eclipsed
All I want is a link to an FCD and some hlep on how to install it. All I asked.

This will only be a band-aid for a bigger problem.

 

[brads]

Ok, in that case I wont bother telling you how far out of whack your settings are, and how badly set up your car must be right now, to get fuel cut at 13 PSI WITH an afc set to -40%. I won't tell you to look for boost leaks, or check your plugs,plug gap and wires to see if that "Fuel Cut" is really a misfire due to that.

http://www.hksusa.com/products/?id=683&rsku=0

is a link to a fuel cut defencer. Not the cheapest one, but then again, you didnt ask for that, and I am just giving you what you asked for.

Please post back here after your engine blows due to the screwed up tuning. It will be good for a laugh. Could you go out and snap some shots of your engine right now, so that we can see some before and after pics too

Thanks,
Brad

Originally posted by Eclipsed
All I want is a link to an FCD and some hlep on how to install it. All I asked.

 

[nine5raptor]

hahaha!

I'll be waiting for those pics as well

 

[kpt4321]

Brad: OUCH!


However, these guys are right. If you were to calculate out the fuel flow of your motor to the airflow at 13 psi, you would find out that you are running an A/F ratio somewhere around like 18:1, which is WAAAYYY too lean.

Think about it.. 550's are 20% bigger than 450's, there is NO reason why you should be at -43 percent on the SAFC. -15% or so would be about right.

I'm pretty damned sure this is a HUGE boost leak. Build a pressure tester and see what happens, I can almost guarantee that will fix your problem.

Do you realize that the FCD simply interceps the airflow signal(s) to the ECU, and reduces them? Putting on an FCD is EXACTLY the same as leaning out your SAFC. EXACTLY. And you're already waaaay too lean, I'm surprised your motor is still in one piece.

Pressure test, and fix ALL the boost leaks. Then turn the SAFC up to about -18% and go from there.

 

[Eclipsed]

OK I will test for leaks. But My EGT's never go past 1500. How am I way to lean? I dont se how I am going to blow my engine if my EGT's never go past that. Ok I will look and see whats up, but a DSM shop tuned my car so why would they set it way to lean?

 

[kpt4321]

Go find the big post 95GSXRacer made on EGT's in this forum, and read it.

You CANNOT tune simply by EGT's.

THINK about the math: 550's are 22% bigger than 450's. So you have 22% more fuel. However, you have the SAFC pulled back 43%. So, at this point, you have approximately 20 PERCENT less fuel then you would with 450's. That's hella lean. Math doesn't lie.

Right now, I am starting to worry if you really have 550's, or if you really should even ever let this place touch your car again.


Do a full pressure test, from the turbo. The car should hold some pressure (5+ psi) for a good period of time, like 20+ seconds.

A hugeass boost leak would ALSO explain why your car is leaned out so much on the SAFC, while still not running too lean when you drive it. Actually, I bet that is the problem.

Make SURE to turn the SAFC back up to -16% or so before you test it again after you fix the boost leaks, or you might lose a motor.

I don't understand why that shop didn't pick up on this.