Rotary Car Club - View Single Post - 1994 RX-7: Xcessive LIM & Fuel Rail install (in progress)

scotty305 · 10-10-2009, 01:18 PM

Not sure about gas mileage yet... have only gone through one tank of gas since getting the car back on the road. It was slightly better economy than the previous few tanks but I've moved recently so the car is seeing different driving patterns than before.

I've tried to adjust injector phasing and ignition timing in an attempt to get the idle smoother with less fuel but haven't been successful yet: leaner than 12.0 and the car tends to hiccup and misfire at idle. Next on the to-do list is adjusting fuel pressure, currently set to about 50psi with the engine off.

I don't think the injectors are to blame, pulsewidths are pretty reasonable at idle (around 2.4ms) and the charts provided by Injector Dynamics show their flow is linear well below 2.0 ms. At 11.5-12.0 it will idle smoothly down to 700RPM, and throttle response seems just as good as it was before changing the setup.

Almost forgot to mention: I originally had the Turbo Control solenoid vacuum lines swapped... pressure went to the vacuum port and vacuum went to the pressure port. Needless to say the car didnt transition properly until that was fixed; boost was normal below the transition RPM but dropped quickly above it.

10-10-2009, 01:18 PM	#8
scotty305 Rotary Fan in Training Join Date: Mar 2008 Location: Culver City, CA Posts: 84 Rep Power: 18	Not sure about gas mileage yet... have only gone through one tank of gas since getting the car back on the road. It was slightly better economy than the previous few tanks but I've moved recently so the car is seeing different driving patterns than before. I've tried to adjust injector phasing and ignition timing in an attempt to get the idle smoother with less fuel but haven't been successful yet: leaner than 12.0 and the car tends to hiccup and misfire at idle. Next on the to-do list is adjusting fuel pressure, currently set to about 50psi with the engine off. I don't think the injectors are to blame, pulsewidths are pretty reasonable at idle (around 2.4ms) and the charts provided by Injector Dynamics show their flow is linear well below 2.0 ms. At 11.5-12.0 it will idle smoothly down to 700RPM, and throttle response seems just as good as it was before changing the setup. Almost forgot to mention: I originally had the Turbo Control solenoid vacuum lines swapped... pressure went to the vacuum port and vacuum went to the pressure port. Needless to say the car didnt transition properly until that was fixed; boost was normal below the transition RPM but dropped quickly above it. Last edited by scotty305; 10-10-2009 at 01:28 PM.