allmotor_2000

No, it does not mean you are running lean (although you should get a wideband O2). It does mean you are stressing your pump and fuel system. The hoses and lines especially the plasticky ones from the fuel-tank are not designed to handle 100+ psi of fuel pressure consistently! At your power level, I think the fuel-pump can still flow fuel... but if you had larger injectors, it might choke.

mrsteve

iTrader: (1)

I have the wideband O2, I just haven't had the time to get the bung welded. At 3/4 throttle I see 95-98psi but once the pedal hits the floor or I really get into the boost (beyond 5psi) the pressure drops.

02AV6

I voted trouble free since the only issue I had was low FP at idle untill I increased to 35psi.

derelict

Allmotor what do you use to monitor A/F ratio?

allmotor_2000

I use the TechEdge WB02 which uses the Bosch sensor. I only really use it to monitor A/F under boost. At idle it just oscillates around 14.7 (14.2 to 15.2 usually). In order to determine the ideal fuel pressure at idle, its best to plug into the OBD2 port with a scan tool.

The Short-Term fuel correction value (this comes from the factory ECU) will tell you what the ECU is doing to maintain 14.7 given current conditions such as MAP voltage, throttle-position, IAT, ECT, fuel pressure and the factory O2 reading. If you are at idle, the ECU is pretty much relying on the factory O2 reading which is affected by the fuel pressure. Ideally you should have +/- 3 % correction. The ECU sets off a DTC when the correction exceeds 18% I believe.

Now, you can set your fuel pressure such that the ECU has to correct -18% or +18% (you have that much margin). But you have to think about what the fuel pressure will be at boost. If you have the S/C Comptech Rise-Rate FPR, it rises a LOT, so maybe you want the ECU adding fuel during idle... so 30-35psi of fuel pressure might be quite ideal. The rise-rate on my FPR is much lower, so I have it at 44psi w/vacuum and 58psi w/o vacuum. Then again, my fuel pressure only rises to ~80 psi at close to 6 psi.

The E-manage now comes into play to correctly add fuel under boost in order to maintain the 11.0 to 12.0 A/F which is ideal anytime under boost (even when not WOT).

mrsteve

iTrader: (1)

Last time I checked you were still using the Comptech FPR. What combination of spring/washer/ring are you using to get such a low rise?