Odd Tuning Issue

[Jacek]

hey guys, i put my rc 550s in last night and set the boost to 14 psi and had the afc set at 40% when i started and i couldnt even get the 02 past .89 volts. what the fuck? note that i just wanted to do a rough o2 tune since its winter, i did try the boost at 18 psi one run and hit fuel cut in 2nd gear (which i started from). so yet again, i am skeptical about my fuel pump being upgraded unless i am doing something wrong. list of mods are:
full exhaust, 19c turbo, 2g maf, rc 550s, uicp, supposed buschur fuel pump, and other studpid crap which isnt important to my problem. how can i check that fuel pump? im gonna see how it is on a datalogger hopefully soon to.

[john]

richen everything up on the AFC. If you are in doubt about it being an aftermarket pump, I would replace it or remove it and see what it says on the side.

[Jacek]

i was starting to think also maybe my fuel pressure has a huge affect of my problem. so it does say what the pump is. someone a while ago told me you wont know.

[Shane@DBPerformance]

Starting at +40% is a lot. You will hit fuel cut very easy if your adding that much airflow signal. You usually want to try to be in the negatives to ehlp avoid fuel cut. Any time that you have to go positive on the AFC, you are putting yourself closer to fuel cut. Fuel cut has nothing to do with how much fuel ther actually is.

The only able to get .89v volt problem could be a bad O2 sensor or do you happen to have a 90 ECU?

I would reset the ECU. And work on fuel trims and low throttle on the AFC. Don't boost at all. Once you figure out where the low throttle settings should be using the fuel trims and driving around a long time just cruising, then use those setting to base your boost/hi-throttle setting from. You should be going negative from the low throttle settings. For example a car 2G with 550s might be happy at about -15% on the low throttle settings and after final tuning at 16psi the hi-throttle settings might be in the -25 range. You car is a little bit trickier with a 2G MAS in a 1G though, the 550s and 2G MAS pretty much cancel each other out and the ECU's fuel enrichment calbration won't be exactly right with that MAS.

If your having to go positive on the AFC on the hi-throttle settings evne with the 2G MAS, then you probably have a fuel supply problem somewhere.

[Jacek]

sorry i forgot to add im a 92