Ok, so im pretty frustrated at this point. I have read posts of other peoples AFR readings straying off. Well two months ago i pretty much got my tune perfect, or as perfect as it can be on this ****ty pisstane in california. Solid 11:1 AFR, Timing numbers are good, no knock, everybody is happy right? WRONG!!!

So i get the CEL flash knock mod, everything is still good only flashes at some partial throttle areas. So this weekend i go out, nothing has been changed with my car, suddenly my CEL is flashing like crazy on almost every pull, im like W-T-F MATE? Hook up the lap top, my AFR is now around the 11.8 range, my car is knocking like a champion at this point, im like WTF. I just went home without richening my fuel map, but what caused this mysterious phenomenon? My thoughts at this point? I dont think its the gas because i had driven three days prior on the same tank of gas, and i got on it a couple of times without any knock.
My question is, im runing 21 psi, stock injectors stock fuel pump. my injector duty cycles have always been 95% + range for the past YEAR,

How did my AFR suddenly change by almost an entire point?

My other question to you Cali guys, At what actual point does an evo8 fuel pump max out? injectors?

Also what AFR ratios do you guys AIM for in cali? and last, but not least has this ever happend to you guys?

 

One of the other guys reported AFR changes with my patch.

What ROMID are you?

This may be due to me not having a stock ROM to base my patch on...

 

im an 05 so 94960011, come to think of it, i did do the NLTS mod before i left tonight lol, but the thing is i made sure to set my fuel maps up, Also i tried to flash to a non modded rom and it didnt fix the AFR.

 

er 96940011*

 

you got a stock 0011 rom you can email me?

 

ya, the fuel maps are stock in that ROM, I think the only thing that is off is the idel rpm haha, or i know it was the idel rpm was off in the first CEL flash mod

 

well I am trying to get a few different "stock" roms - the most common ROM (except for the immobilizer) is the one I will use.

Cheers
D.

 

My past experiences usually end up hitting a lower load area which in turns leans out my map. I have since compensating by taking careful notes of where it generally seems to fall under then going beyond those points smoothing out the map. In another thread MASSIVELY lean AFR's where caused by the regulator vacuum line popping off.

I have no idea when a fuel pump will max out and personally I don't even plan to try. A 255 walbro is so cheap its not even worth playing with IMHO. Currently I'm stocking up pieces for a better fuel system setup with an adjustable regulator, rail (mostly for looks ), and 780cc injectors + pump.

I use a leanspool off map btw which has proven to be pretty useful to me making my understanding of the map and why the hell it does what a little more tolerable. After a manually entered lean spool up my map runs 11.1 AFR topping out at 11.2 by the end of the rpm range.

 

come to think of it, i know for a fact that the line teeing off to the FPR might look a little kinked, but i have noticed it before and i just ran out to the garage and it still looks ok, its that clear nylon tubing so its suppose to keep from collapsing in, I think ? haha, just to be sure i am going to re do it tomorrow.

 

I'm pretty sure collapsing is damned near impossible with that hose. Under normal boosting conditions it would actually be experiencing positive pressure instead of vacuum.

The only cases I've heard are of the line blowing off not being pancaked under vacuum.

 

ya, well best thing i can do, is just richen up my map for now and order a walbro 255. Also the way i have the T set up it kind of forces is to kink. Plus my boost gauge is tapped in to there so i would know if it blew off because it has happend before.

I know this seems stupid, but could the flow efficiency of the fuel pump just decay a little bit? Generally fuel pump wise it either works or dosent, but i like getting in to possible minute details . Also FPR minutly letting more fuel return (thus decreasing fuel pressure to the injectors) haha too technical at this point?

 

Not to sound like an *** but WHY in the name of all that is holy did you tap in your boost gauge to the regulator line on the fuel rail?

If your boost gauge develops a small pin leak your going to of coure experience less fuel... Do me a favor replace the line to the regulator with fresh 1/8 vacuum hose and see if your AFR drops.

 

well, if you look at an MR, that is where the factory boost gauge is tapped in to from the Factory, So i figure it would be the way to go.

 

Interesting learn something new everyday thanks

 

Yeah i think if you go to the how to section here on Evo M, the write up talks about using that as the source because they put a T in that line from the factory for an MR's boost gauge.