Quote:
Originally Posted by Beedub
YES...... this would be indicating injector max out which isnt going to happen on those new items you have..... im guessing their is no REAL way to see how far were pushing our pumps..... Rated, in fairness, your pump may be more than capable of supplying the fuel BUT due to age and miles its just tired....
how many miles you on now?
|
The car has close to 27k miles, so not very old. There is another factor that came to mind when reading this thread:
http://www.m3forum.net/m3forum/showthread.php?t=429288. The guy was having a similar problem and while the pump may be able to supply the fuel it looks like the lines may be too small and causing too much resistance/restriction of higher flow. Larger lines would actually decrease resistance and allow the pump to operate at a higher efficiency/rate. This along with an inline pump just to be safe might be another option. Now to the injection timing decreasing; if the ECU is seeing that the pump can't supply enough fuel at a certain point (because the lines are to restrictive, for example), then maybe the ECU is cutting the times because of the pressure drop. I'm not sure if this is a factor in the ECU's calculations, but possibly.
Either way, bigger lines and an inline pump can only help and aren't all that expensive. I'm just curious as to the the effects of doing so with the computer controlled FPR.
Here's what the guy, in the thread I linked to, did with his fuel system (he's running 12 psi though with meth, but experienced the same lean issues like I am before the upgrade).
42lb injectors
Aeromotive 340 sealth fuel pump (best choice)
larger fuel lines and relay.
Aeromotive fuel filter
Walbro inline fuel pump
AA bigger Fuel Rails
Aeromotive Fuel Press. Regulator (3bar)
50/50mix boost jucie Meth spary at 2.5psi to redline using .630cc jet
FPR gauge at idle reads 63-64lb. (with 60lb inejctors it should be at 43lb of pressure)
Quote:
Originally Posted by aerobod
I believe that under WOT conditions the car should be running open loop and there should be no feedback from the O2 sensor (unless a non-OEM wideband sensor is being used).
If the data logging in this case is giving true information, the fact that fuel pressure doesn't move from 6 bar would indicate that fuel flow demand is being met. I would expect that if fuel demand couldn't be met, as the injector open time increases, the pressure could not be maintained due to flow limitations.
Rated, do you have any more data logging information available (such as fuel trim, throttle position, etc)? Also, I may have missed it, but does your installation make use of wideband O2 sensors, or is it using the standard OEM ones?
|
I don't have any other data logs at the moment, but I did record the driver input via pedal during the runs, which basically just shows I was on full throttle. I'm using the readings off of the OEM sensors.