We had a dyno day yesterday with a bunch of NECEG people. Alot of the cars were very similar mods, ported 3L, etc. All the untuned 3L's put down in the area of mid to high 180 whp, and all had air/fuel ratios in the mid to high 12's. My car went on the dyno towards the end, and had the lowest HP. My highest pull was 179 whp and 163 torque. The interesting part was my air/fuel ratio was dangerously lean, high 13's and into the mid 14's!
Here is where it gets screwey. I have been trying to diagnose a P0172 code for a couple weeks now (bank 1 too RICH). I data-logged the long term fuel trims on both banks pulling upwards of 20% fuel out to try and correct itself.
After the dyno pulls, I pulled the car into the shop and messed around with it. I took a measurement of fuel pressure from the shrader valve, and it was 80 psi at idle! when i revved the engine, it would drop.
My question is this, what could make the car run lean, think it is running rich, and give it crazy high fuel pressure. The first place I plan on looking is at the pressure regulator.
This may be a tuning question here, but if the fuel pressure on low throttle conditions was crazy high, but at full throttle it was dropping, would that explain it? would the computer see too much fuel most of the time, try to lean it out, then on full throttle conditions it is now too rich? My fuel mileage is also low, like 22mpg.
Here is where it gets screwey. I have been trying to diagnose a P0172 code for a couple weeks now (bank 1 too RICH). I data-logged the long term fuel trims on both banks pulling upwards of 20% fuel out to try and correct itself.
After the dyno pulls, I pulled the car into the shop and messed around with it. I took a measurement of fuel pressure from the shrader valve, and it was 80 psi at idle! when i revved the engine, it would drop.
My question is this, what could make the car run lean, think it is running rich, and give it crazy high fuel pressure. The first place I plan on looking is at the pressure regulator.
This may be a tuning question here, but if the fuel pressure on low throttle conditions was crazy high, but at full throttle it was dropping, would that explain it? would the computer see too much fuel most of the time, try to lean it out, then on full throttle conditions it is now too rich? My fuel mileage is also low, like 22mpg.