a Missing 2nd o2 sensor, would it not being eliminated do this?

[Lordpaxin]

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Ok,
the problems.

car will not accelerate when cold, just bogs until heated up a little, then at mid throttle position it will bog all the time, and if you wot, it bogs then picks up and goes.

it blows black smoke (fuel) at any kind of attempt at hearty acceleration, once it gets going, it hits fuel cut at 4500

evo 16g set at 14 psi
450cc on walbro 255 NOT afpr'd
3 inch turbo back.

what i am asking is, stock injectors should run perfect with stock fuel control right? IE the safc2 zeroed out.

i looked under the car and there is no 2nd 02 sensor, if this sensor was just takenout, and not eliminated could it casue these problems?

also, it will sometimes blow a big long fire bolt out the exhaust thats blue and orange.

 

[justin0469]

well obviously you are running way rich but i drove around with a broken off 02 sensor for a few months and i didnt have any problems except the CEL and maybe running slightly rich cuz the ecu didnt know what my emissions were lookin like after the cat

 

[Staytuned]

No removing the rear O2 sensor will not do this. It's only function is monitor the cat performance.

 

[Lordpaxin]

well shit.

would possibly the stock pressure regulation and the 255 wally do this?

 

[justin0469]

double check that the afc is zeroed out and you said you have stock injectors right?

 

[andymoraitis]

well shit.

would possibly the stock pressure regulation and the 255 wally do this?

I'm no AFC guru but I can tell you for sure that if you have a 255 on stock injectors with no AFPR, then you'll run too rich from the get go. You may want to actually lean out the AFC since you have overrun, or buy an AFPR and correct the problem at the fuel rail. Running the AFC with zero correction factor is like telling it that everything is stock, which it's not. Pulling your plugs will tell you the whole story. Twenty bucks says they're black and fouled which will certainly cause hesitation and even induce rich knock (your timing will be pulled at higher RPM's just as if it was running lean). If you want to avoid an FPR, go with a 190 instead of the 255.

 

[Nanan]

The Walbro 255 lph fuel pump is likely your problem because you are overrunning your stock fpr. I would suggest getting an aftermarket adjustable fpr like the B&M commandflow. You should also have an AFC or reporgramable eprom setup if you are at the evo3 16g stage already.

 

[Lordpaxin]

Ya, thats what i was thinking.

all the AFPR kits i see are 300$ plus. which sucks for a broke ass like myself.

thanks for all the reply's

 

[Staytuned]

I ran a stock FPR and a 255 for a whole summer and never experienced anything like what you have.

Keep searching for your problem.

Edit: also borrow a logger and see WTF is going on with your o2 values and timing.

 

[Zex4g63]

The B&M command flo is a fuel pressure riser. It will do NOTHING to lower your fuel pressure. It still uses the factory regulator, just allows you to preload it more to raise fuel pressure. Do not waste your money on it. Your options are buy a real regulator or a smaller fuel pump.