need help, dunno why so lean

[blizz99]

Ok, well i just installed a hx40, lucas 1200cc injectors, punishment racing o2 housing, and synapse 40mm ewg. I started the car up and it's idling lean...and by lean i mean it reads --- on the aem uego. even while driving it's lean. i've tried messing with the fuel settings on dsmlink and it's still lean. anyone wanna come check it out or have any ideas?

 

[Friend-O]

Could be the 02 sensor for the WB. I ve got a slight leak I am fixing in a couple days and right now my WB reads about 2 points leaner than actual. what does link say for your 02 in closed loop?

 

[innocenttalon]

faulty wideband sensor? does it even read/sweep or just stays lean?

 

[blizz99]

when you first start it, it will read around 14.7 then it'll start leaning out within like 20 seconds. also, when i hit the gas, there's a lot of hesitation

 

[Friend-O]

sounds like you may have a small leak somewhere pre sensor. mine does the same but link says my startup is in the 13's . the display goes blank --- due to not enough input but once you throttle it a bit it should kick back on. To be honest the WB is only very useful when doing open loop operations since before that the front o2 is in charge and can give you good positive feedback, though I wont discredit it as useless to do a sanity check on the front o2. if there is hesitation that would indicate a too rich condition possibly also making the WB go into ---. Check your global fuel settings to be sure they are correct if you haven't already yet.

 

[blizz99]

sounds like you may have a small leak somewhere pre sensor. mine does the same but link says my startup is in the 13's . the display goes blank --- due to not enough input but once you throttle it a bit it should kick back on. To be honest the WB is only very useful when doing open loop operations since before that the front o2 is in charge and can give you good positive feedback, though I wont discredit it as useless to do a sanity check on the front o2. if there is hesitation that would indicate a too rich condition possibly also making the WB go into ---. Check your global fuel settings to be sure they are correct if you haven't already yet.

the global is correct on it. so you're saying it's an exhaust leak? when i get on it, it still hesitates. when driving, it's reading lean. at idle, it's reading lean.

 

[Friend-O]

If you log your front 02 and it also shows you running lean then you can adjust your maf or fuel trim settings depending on what doesnt match. you should be pulling about 40-50 Hz on a maf at idle and If i remember right about 32 Grams per rev. hesitation on accel sounds like it could be a fuel delivery issue so log your injector flow and see if they flowing correctly. also check your base fuel pressure if you have an AFPR. If it was just your wideband reading lean then its an exhaust leak, but if the car hesitates then it s a fuel delivery issue likely

 

[jeffo]

1) The Lucas "1200cc" injectors actually only flow ~1120cc on average.
2) They have rather huge deadtime, so you need to add 400-500uS or you will be lean at idle.

 

[GSXeclipsePSI]

I too am having the same problem and have these same injectors. No matter what changes I make in my flash I can't get the idle AFR to change

I have a small exhaust leak at the 02/downpipe.

I have the injectors scaled to 739cc for my AFR_Map to match WB at WOT. I had the car dyno and the reading at 6500rpms was 11.08 at the muffler. I have my maps set to 11.2 with the above settings. My battery comp tables lowest number is .600 so I'm guessing I'm .300+ over stock.