KA-t going lean

[92KA-T]

please help me.. not sure if anyone has had this problem but my car goes really lean as soon as it hits 3000 rpm and keeps getting leaner seems like the fpr isnt doing anything thats when i hit boost on low throttle its fine.. when i get in it it goes lean at 3000 and keeps gettin leaneranyone thats got any input please help

[lancet913]

Do you have a walbro 255?Stock fuel pressure regulator?

[92KA-T]

walboro with a sr fpr i had in the garage it didnt do it before but now it just started

[480sx]

Why dont you just add more fuel with the safc to the points that your going lean?

Also, AFC's are great at destroying motors. They should never be used as soul tuning devices. A RRFPR is a much better 'cheap' option for a low budget build. It should be used over a SAFC any day of the week.

SAFC is good for two things. Fine tuning a rom tune, and MAF sensor input translating.

[92KA-T]

safc has worked great before then i rebuilt the motor and had some timing issues .. then got that fixed.. and now i got the safc2 maxed out at 50% after 2800 rpm and on 7 psi its at like 12.5 afrs before i had it at like 12 psi and it wasnt close to maxed out... i dont know what it could be.. did a pressure test on the pump while car was running and it was at 45-50 psi and pulled the vaccume to the fpr and it jumped up 10 psi so that seems like its working.. ill post up all my safc settings and see if anyone knows whats up..

[92KA-T]

so on 7 psi i got the safc maxed and its running 12 afrs under boost.. put a new mas air on it and a different safc still the same thing... please help...

[motoman399]

sorry a little off topic but what is this "RRFPR" i know its a fuel pressure regulator but what is the "RR"

[92KA-T]

rising rate fuel pressure regulator

[480sx]

SAFC would also work well with a RRFPR. Like i say, AFC's are great at fine tuning, so simple and cheap. They just suck as soul tuning devices. Tricking your ecu into thinking that say.. 50 percent less air is coming in than there really is advances your timing maps considerably. This is why SAFC's so often blow motors, they mess with stock timing maps almost always adding timing when you should be doing the exact opposite.

[92KA-T]

i dont know it worked well before.. ill go pull a rrfpr off of a car i know of in town and see what that does.... im thinking about selling the whole ka-t set up and going with a sr

[480sx]

Sorry i missed your reply that described your issue more in depth.

Well, unless your gauge is off, your fuel pressure is considerably higher than normal. You should be at about 43 without vac, and 38 with vac(at least thats what it is for a Ka, im not sure about a SR but i cant see it being much different, same style injectors). Id say its possible you have a FPR issue. Id check it with another gauge. Honestly you should just get a performance FPR and dial it in.

However, that still makes this even more bizarre because you should be over fueling, especially at +50%. The stock FPR doesnt do so well with a 255 pump in it. You get pressure spikes when it kicks on and they fail after time, they wernt designed to handle that much extra fuel flowing through them.

Thing is, you have no idea what your fuel pressure is when your under boost or load. You could have a stopped up fuel filter, your injectors could be clogged up, or your fuel pump could be fowled.
Modified by 480sx at 11:25 PM 2/17/2009

[92KA-T]

i going to go ahead and try some other 370 ccs from a buddy that has them arround and its a stock SR fpr.. im going to try another if i can find it.. i keep thinking its the pump thats going out but cant be for sure once i try the other injectors and other fpr ill go ahead and get another pump.. and i might try my buddys 12 to 1 fmu and see what that does..

[NateDogg]

new 300zx z32 fuel filter?

[92KA-T]

tried a new filter.. now im just thinking about a new pump.. not sure what to do..

[480sx]

Fuel pressure check while on a dyno will tell you how your fueling system is acting. That will at least rule that out. I wouldnt just start swapping parts until you figure out whats going on.

In addition, you can double check your AFR's to those given to you by your WBO2 system.

[92KA-T]

dyno=75 and if pump is bad.. then another 80... idk my buddy has a pump in his car he will let me try out..

[92KA-T]

thinking maybe just maybe.. 10% ethenol is throwing the wide band off??

[s14 ka-t]

hey man i have the same problem. do u resolve something?

[480sx]

dyno=75 and if pump is bad.. then another 80... idk my buddy has a pump in his car he will let me try out..

What does this mean?

thinking maybe just maybe.. 10% ethenol is throwing the wide band off??

No.

[92KA-T]

i ment to say dyno is to expensive

[2FourTee]

SAFC would also work well with a RRFPR. Like i say, AFC's are great at fine tuning, so simple and cheap. They just suck as soul tuning devices. Tricking your ecu into thinking that say.. 50 percent less air is coming in than there really is advances your timing maps considerably. This is why SAFC's so often blow motors, they mess with stock timing maps almost always adding timing when you should be doing the exact opposite.

I wish I could get the local Nissan guys to understand this. They all think KA's are junk, and it's because every person who does ka-t in this area always uses a SAFC. I just can't get that timing thing through their heads.

[92KA-T]

i understand what you are trying to say.. but it has worked well up untill now.. as soon as i figure this out it should be nistune... with a holset hx35 maybe

[WDRacing]

I wish I could get the local Nissan guys to understand this. They all think KA's are junk, and it's because every person who does ka-t in this area always uses a SAFC. I just can't get that timing thing through their heads.

I used the SAFCII with 42lbers when my car was running. Took a long time to get it tuned to what I consider to be decent though. I was able to run 1 bar daily...BUT...I used the MSD BTM for timing retard on boost.

I don't know why more people don't use it Works awsome, set it and forget it. Run low octane fuel by mistake? Turn the knob a little to retard a little more on boost...done and done. I ran 87 a couple times when I was short on cash with no problems.

WD

[480sx]

Thing is, its ~200 for a SAFC2. Then its 300+ for the BTM. They arnt that common to find on the forums. At 500 bucks, you can get a tuned ecu and be done with it.

[WDRacing]

When I started, there was only JWT...

Actually, if you want ultrac cheap, just go with a hacked MAF and BTM. BTM is 250 btw.

[eazye2000]

Get a board, and some chips. I'll tune your 'ish for free. Tell me what you got. Just make sure you get at me when I'm not inebriated. haha

[92KA-T]

well nistune seems to be a good option out there not to expensive.. and a buddy here in town will tune it for me.. is there any other boards like nistune out there for the KA?

[92KA-T]

well went out and got a fmu.. set the SAFC to 0% on high and it even goes 10.5-11 afr under boost.. sweet.. but my boost sometimes goes to like 15ish and sometimes stays at like 7 depends on gear.. this might be the boost controller though.. and it smokes like a fraight train i think the turbo is DONE