ive been reading about the injectors and now have some questions that are not clear.


just listing for reference since i was looking for it.
rdx stock fuel pressure 50 psi
RSX stock fuel pressure 47-54psi? manual doesnt specify type-s or not
integra stock fuel pressure LS 40-47psi, GSR,ITR 47-54psi(many people give out incorrect info on this one stating 43psi is for all integras)like swapping incorrect FPR on yor LS motor etc.
02-03civic EP3 47-52psi
s2000 stock pressure is also 47-54psi
im assuming RDX service manual also says 47-54psi?

1 ill use RDX injectors as an example.
from this webpage i got the charts
http://www.8thcivic.com/forums/super...injectors.html


the pressure is measured at 50 PSI RDX injectors are labeled 410cc
but according to this flow chart of 8 injectors they flow at almost 480cc at 50 psi




i set my fuel pressure at 50 psi
when idling the fuel pressure drops about 5-10 psi (mine is at 44psi at idle)
which is 440cc according to the chart.

when i rev the engine up the fuel pressure drops a bit more like 3-4 psi so im at 40 which is425cc

now with that said.

what injector flow do i enter in my injector calibration field?
because if i put 410 thats not what they are really rated at.
if i put 480 thats only with engine off
if i put 440 thats only at idle.



i also couldnt find any definite info about the pressure drop while accelerating.
is it suppose to stay dead on 44psi if its like that at idle or is it normal for it to let off 2-4psi while accelerating?
im just trying to troubleshoot further.

because the car was tuned witn stock fuel pump. i thought a walbro190hp would make it run rich but it didnt it runs exactly same.(the walbro pump is only 2 years old)

 

As you have found, actual numbers vary from car to car, pump to pump, even actual flow from injector to injector. Relatively speaking, things are close enough (usually). You shouldn't be seeing a pressure drop when you snap the throttle. The FPR should INCREASE fuel pressure to maintain a pressure differential between the fuel rail and manifold pressure.

Sometimes we tend to over-think things. What really counts is how the car runs when done. What you might want to do is enter a value and see how it does in the real world. Tweak your injector flow values to where your tables seem to work best at the lower end of the power curve (safe zone), then work your way up.

I never got things "perfect" just by getting the parameters right. There will always be a bit of tweaking.

I know this wasn't a direct answer to your question, but I hope it helps.

Mike

 

Most computers will want to know the injector flow without the vacuum line hooked up. So for instance if you set your fuel pressure at 50psi without the vacuum line that is the number you should be using. However not all systems are the same. What EMS are you using?

 

neptune.

so that means when i set it at 50 psi with engine off thats what i need to use in the injector calibration as well?
480cc then because theres no vacuum without engine running.

i was just making sure i did this right. thats what i set it at.

 

Whatever fuel you add with the injector calibration you can remove with the map. As I understand, the main advantage of the injector calibration is that if you have the car tuned on one set of injectors, then change injectors, you can dial in the AFRs using the injector trim without ever touching the map.

By that reasoning, if you're starting from a tune and changing injectors, tune the injector calibration by AFR monitoring. And if you're starting a new tune on new injectors, just best-guess the injector calibration and tune on the fuel map.

 

makes sensei

 

dude, you're asking a lot of questions that have already been answered. download the manual in my sig, and go to the forums at PGMFI.org