Running Lean?? How?

[kchaazz]

HELLO THERE. IM HAVING A problem with my fuel trims, big time. mods are in my profile but the most recent things ive just done is put my wally 255 back in, installed an obx (i know its not a good one) afpr, and an 18g turbo. im not getting any more than 1 count of knock at 17 psi, im getting from 18- 20 degrees of timing advance. my fuel trims are all at 118.7%!! i just dont get it, base fuel pressure is at 38 psi, with the line off. the car runs and idles great with 19 to 20 inches of vaccuum. i just dont understand, i can crank my fuel pressure to 45- 50 psi and itll still say im a bit lean. gas mileage is a bit crappy as well with perhaps a little over 215 miles to a tank. car did have a bad studder under boost but new ngk 7es plugs and new wires fixed that.

please help me out here. is it my 02 sensor, is the guage on the obx fpr off, or is something even more sinister in the works here?

 

[timloomis]

what size injectors you have?if you still have the stockers that could be your problem.with my maft,my low fuel trim is still like 139% after i reset the ecu.so hopefully after a few days thatll go away.it does take a while for the trims to change.

 

[kchaazz]

just a couple more things i left out

well, i have a set of denso 660cc injectors, but theyre not in yet cause i need new o rings , the ones that go into the intake mannifold, so i do have an afc 2, but its zeroed til i get the 660 in. one thing, the car is taking longer to start since the 255 install, and its not the fuel leaking past the oring seal on the pump where the nozzle goes into the line cause i cut that part of it off and just clamped a hose to the pump then the hard line on the sending unit. when the car starts, for a minute or 2, itll bog when im giving it gas at idle which leads me to believe that there is air in the fuel line during this time. the car will idle just fine even if i turn up the fuel pressure to 60 psi which shouldnt be possible? is it possible that the guage on the regulator is way off and also that the diaphram in the reg is allowing the fuel in the line to bleed back through the return and thus causing the extra cranking time to start the car and the initial bogging when i touch the accelerator?

 

[v8s_are_slow]

alright man, i found a link for ya.

http://www.pocketlogger.com/index.php?pid=1gtech_trims

hopefully that'll clear things up for ya some. and notice #3...talking about running lean.

the O2 trim as well. since the fuel trims take so long to move around, use that as a guide to get your trims in the right direction. i know i can adjust my low trim with my maft and watch the O2 trims either go high or low and adjust accordingly right then and there and watch the results of the low trim start to move. since it takes a lil while for the mid and high trims to move, that's where it comes in handy to watch the O2 trims. it'll either show high or low. for example, your trims are at around 80% and you wanna lean it out. if you adjust and the O2 trim cycles around 130%, the mid or low will follow later on. just don't be doing a WOT run or decel while doing the adjustments.

but i'm sure you're running okay with 118% with no knock and timing not being pulled.