got my car tuned. according to the wideband, i was running very lean at around 17afr cruise and wot. according to the tuner, this is what ive been at for the whole 8 months ive had the motor.

we richened up the fuel maps. im now at 112% duty cycle to keep the afr happy around 13 during wot.

the problem is, the motor is a bone stock jdm itr. chassis is a eg hatch. fuel pump is stock, fuel filter replaced several miles ago. based from my knowledge, its bone stock motor... or is it?

no idea what my fuel pressure is.

anybody know what might be the problem? why do i need to be at over 100% duty cycle for a bone stock motor?

 

Can you even have over 100% duty cycle? I'm pretty sure that 100% is open all the time.

Your options are to increase fuel pressure or install bigger injectors. Either way, bone stock or not, stock injectors should suffice.

 

Well, this is where you really need to do some learning. First off, duty cycle can't go above 100%, the injectors would be permanently open pumping the maximum amount of fuel they can the whole time, no matter what RPM. Secondly with putting in a bigger motor you might have learned that a stock fuel system for a smaller engine often times won't be sufficient to fully utilize the new motor. Go spend maybe $100 or so and get a Walbro 255 fuel pump for the EG. Lastly, do us, and yourself, all a favor and do your research before you do something to the car again.

 

Get a marshal fuel pressure guage from alchemist for 39.00 shipped. You could also get an adjustable fuel pressure regulator and jump up psi by about 10 pounds.

Also like in your other post if tuned on crome then the injector duty cycle is going to read higher than it says. If so keep adding fuel til your AFR is right and if you add fuel and AFR goes down and Injector duty cycle goes higher then you know your injectors are still opening.

Or get them flow tested to make sure they are performing at peak.