My motor is freshly rebuilt with JE, Eagle... and 440CC used before by agression. (Dont know the brand exactly)

My fuel setup is Walbro 255, S-FMU, 440CC. My fuel idle fuel pressure is around 22psi. Car idle a little rough but no black on the back bumper. I got a cel is I let it idle for rich. On idle my a/f (read on apex'i turbo timer) show 14.4... 14.8 but if I press just a little on the gas it drop to around 13..12... if I press a little more it will go to 11 and 10 (Of curse Im waiting for my wideband but that gives me idea). My mpg is bad and Im boosting only 5psi for now.

Is it a good idea to buy safc and lean out at low rpm ? Will I see better mpg and get rid of the cel ?

Is it better to drop the 440CC and buy some 310CC or 330CC ?

I will probably never exceed 15psi of boost.

Originally posted by ChloRure
My motor is freshly rebuilt with JE, Eagle... and 440CC used before by agression. (Dont know the brand exactly) My fuel setup is Walbro 255, S-FMU, 440CC. My fuel idle fuel pressure is around 22psi. Car idle a little rough but no black on the back bumper. I got a cel is I let it idle for rich. On idle my a/f (read on apex'i turbo timer) show 14.4... 14.8 but if I press just a little on the gas it drop to around 13..12... if I press a little more it will go to 11 and 10 (Of curse Im waiting for my wideband but that gives me idea). My mpg is bad and Im boosting only 5psi for now. Is it a good idea to buy safc and lean out at low rpm ? Will I see better mpg and get rid of the cel ? Is it better to drop the 440CC and buy some 310CC or 330CC ? I will probably never exceed 15psi of boost.

Those used to be my injectors :) lol.

Well, at 5psi, your way over kill with 440's man, thats why your MPG is terrible.

Your code will almost always be there. You are more than doubling the stock injector size, so you figure the stock ECU is gonna read rich. Dont worry about the code.

As far as the turbo timer reading the a/f, that timer reads in narrowband ratio's, not actual. I bet once you get a wideband, your going to see whats it actually reading.

yup you really need a wideband

So ill always have the cel ? Any way to avoid this ? Thats bad when you got other code and you dont know cause the rich one is always there... I dont want to make the keydance each time I want to drive it.

Mike, do you remember the brand of the injectors ? Flow well on lower psi ?

As for the wideband I just dont know wich one to take... zeitronix is nice at 279$ but I dont have a laptop, so its more 399. AEM come with a gauge for around 240$ but cannot read below 11 a/f.

I was wondering if I get a wideband, for now I have the oem hrc downpipe soldered to my oem exhaust until I get a 3" catback to fit my 3" hrc downpipe, and I put the sensor in place of the oem o2 and connect dont know if you can plug the oem one on the zeitronix but that will get rid of my cel right ?

Im not sure if its a good idea to swap to lower cc injectors since it will be a pain in the ass to swap them with the motor in the car and if I got a boost spike or want to run 15psi... at least im sure that 440c can hold that.

Originally posted by ChloRure
So ill always have the cel ? Any way to avoid this ? Thats bad when you got other code and you dont know cause the rich one is always there... I dont want to make the keydance each time I want to drive it. Mike, do you remember the brand of the injectors ? Flow well on lower psi ? As for the wideband I just dont know wich one to take... zeitronix is nice at 279$ but I dont have a laptop, so its more 399. AEM come with a gauge for around 240$ but cannot read below 11 a/f. I was wondering if I get a wideband, for now I have the oem hrc downpipe soldered to my oem exhaust until I get a 3" catback to fit my 3" hrc downpipe, and I put the sensor in place of the oem o2 and connect dont know if you can plug the oem one on the zeitronix but that will get rid of my cel right ? Im not sure if its a good idea to swap to lower cc injectors since it will be a pain in the ass to swap them with the motor in the car and if I got a boost spike or want to run 15psi... at least im sure that 440c can hold that.

the 440's you have are overkill for 5-8psi. I ran 16-18psi with those injectors okay. You cannot unplug the oe o2 sensor and replace it with the zeitronix one. If the oe PCM doesnt see your o2 readings, your car will run like shit. You need to keep the oe sensor in there, get used to the CEL, it will come and go as it pleases. Try lowering the pressure down to 20psi. Also if you wanna get rid of it for sure, get an S-AFC and lower at 1k RPM down to like 18%. I had those injectors running with an AFC before as well.

Brand is Bosch for the Injectors I believe, its been awhile, but I think im 97% sure they were Bosch from Summit Racing.

Originally posted by eclipse982nrRST
Try lowering the pressure down to 20psi.

Or lower. it helps if you have access to a datalogger, that way you can watch your short term fuel trims adjust into a range that won't cause a CEL.

Im afraid to go lower than 20psi, do I keep same disk/spring into the s-fmu ? As for bosch injectors, are they well designed to flow at low psi ?

Oh and when I go on the highway and push the car I can smell the gas coming... smell hard, is it normal to smell it like that ?

thanks :)

if you smell gas like that your leaking it. i have 500 cc and i run 20 psi at idle with a safc II,large disk small hard spring combo.

Smell if when im at wot and it will stop when I let the gas off after around 5 sec. Maybe leaking only on high pressure.

I ran 18psi Idle pressure with those/.

Perfect, ill try 20psi and 18psi. Anyone knows if you can read the fuel pressure at an electric gauge other by the gauge itself ? I mean with a multimeter, because its hard to really see wher the needle point on the gauge.

Update... this moring my girlfriend was behind me on the highway and only when I push the car (ex: to enter the highway) she saw some fluid coming out of the car but on the opposite side of the exhaust so I guess it was fuel since she was able to smell it.

But how this can happen ? My return line is direct from the sfmu under the hood to the tank... and I see no leek at the tank. The only thing I remember is that I just cut the hose of the old fpr and than route another one from the sfmu to the tank and leave the old one in place... do I need to remove the old one ? Dont think anything flow in this one.

Anyone ?

what year is your car? is your factory FPR on the rail? and if I read that right did you say you just cut the hose from the factory one and left it??? not bashin on ya but you need to be a lil more clear on this one cuz it sounds like you just let the fatory FPR dump out all over the engine bay.

not to threadjack or anything but im setting up a similar system, except im using DSM 450cc injectors and i was wondering about the SFMU...mine doesnt hold pressure when i pressurize the fuel system. it spikes up to what pressure its set at and then it drops down to 0. is it supposed to do this?

Originally posted by quicksilver99
what year is your car? is your factory FPR on the rail? and if I read that right did you say you just cut the hose from the factory one and left it??? not bashin on ya but you need to be a lil more clear on this one cuz it sounds like you just let the fatory FPR dump out all over the engine bay.

What I did is cut the old return line that goes from the old fpr to the tank and put a bolt in it to avoid gas going out. But now I have the old fpr and the smfu hooked up at the same time, I will try to find i way to remove the old one and connect the feed line direct with the fuel filter.