LEan idle and 2 plugs look lean HELP !!!!

[boost69]

hey guys im not sure whats going on with my car maybe some one will know, my wide band reads in the 16's and low 17's sometimes at idle and when normal driving it reads in the 15's and wot it will read around 11.2 i changed the plugs today and the two plugs on the right side had the white char on there showing its running lean but the other two seamed fine, im not sure whats up with it maybe you guys can shed some light ...Thanx

 

[SBR Joe]

Its a little leaner than what youd want to normally shoot for at idle and cruising....but shouldnt hurt anything. Depending on what you have for fuel mods/fuel control (mainly SAFC i speak of here) it may just be that way as a result of the ECU trying to compensate one way or another when being tricked.

WOT AFR is about spot on where you want it. Does the car spit and sputter or kind of dog when cruising part throttle? Also, which 2 plugs look lean? Im assuming youre basing this off the fact that the electrode tips were pearly white? What color were the others?

 

[LiquidX]

Idle can be leaner than 14.7 since there is no load on the engine. Once you start loading it up is when you'll have issues with melting and detonation. You could just adjust your fuel for the low end using the SAFC if you are that concerned.

 

[boost69]

if your looking at the motor its the two plugs on the right hand side , and it doesnt sputter or anything when cruising, it did sputter and break up at WOT cause of the plugs were gapped to big they were at .035 and i put fresh ngk 7"s gapped at .28ish and it seems to run smoother havent tryed any WOT pulls yet to see

annd i forgot to mention the other 2 plugs were like the brownish color

 

[SBR Joe]

if your looking at the motor its the two plugs on the right hand side , and it doesnt sputter or anything when cruising, it did sputter and break up at WOT cause of the plugs were gapped to big they were at .035 and i put fresh ngk 7"s gapped at .28ish and it seems to run smoother havent tryed any WOT pulls yet to see

annd i forgot to mention the other 2 plugs were like the brownish color

Ok, well, cyl 1 and 2 are the leaner burning of the cylinders...so that may be something to think about. What fuel mods do you have?

 

[LiquidX]

I'd say run some injector cleaner in the fuel if you have the stock injectors. Might be a little gunked up.

 

[boost69]

im running a re wired 190 lph and 550s, and also im running about 19 psi, as well as my fuel pressure gauge on the rail reads about 41psi

 

[SBR Joe]

im running a re wired 190 lph and 550s, and also im running about 19 psi, as well as my fuel pressure gauge on the rail reads about 41psi

You have anything for tuning? What turbo?

 

[boost69]

its a small 16g, and it was dyno tuned by the previous owner and fitted with a keydriver chip, i have the safc hooked up but dont use it, also how much boost can with that set up and that fuel pressure of 41psi?

 

[SBR Joe]

19-20 psi is about what youll want to keep it at with the 550s, maybe a tad more since its a small 16g, i know on my winter beater 1g, with a similar setup, i was about maxed out on duty cycle at 20psi on an EVO 3 16g using the EVO 560cc injectors. Do you have an adjustable fuel pressure regulator? Or just the gauge and a stock FPR?

 

[boost69]

its a aem adjustable fpr i think i read somewhere that the 190lph fuel pump would only make 43 psi, not sure if that true or not but my gauge reads about 41 psi, so if that is true i would be almost maxing out that fuel pump and i not sure how much psi will max out those injectors, if you know that that would help me out alot as well

 

[SBR Joe]

its a aem adjustable fpr i think i read somewhere that the 190lph fuel pump would only make 43 psi, not sure if that true or not but my gauge reads about 41 psi, so if that is true i would be almost maxing out that fuel pump and i not sure how much psi will max out those injectors, if you know that that would help me out alot as well

Did you set the base FP with the vac line off? Or is it reading that with the line on?

 

[boost69]

i didnt set it the previous owner had set it , and thats what its reading when the car is running

 

[SBR Joe]

i didnt set it the previous owner had set it , and thats what its reading when the car is running

Ok well thats too high then. Set it at like 40 with the vac line off, since youre running a 190, and then see what the car does.

 

[boost69]

wouldnt that make my car run more lean? and how will i know when im maxing out my injectors?

 

[SBR Joe]

wouldnt that make my car run more lean? and how will i know when im maxing out my injectors?

Theoretically yes, but if thats true about the max PSI for the pump then it could just be maxing out and slacking on the fuel volume. That would show more so on the WOT air fuels though, not so much with off throttle air fuels. Also, Jeff bases the chips he makes off a 43.5 base fuel pressure, so if its not at that, it may throw it all over the place.

For the sake of argument, set the FP at 43.5 with the vac line off and see what the car does and get back to me.

 

[boost69]

ok will do thanx

 

[Coolhawk00]

ok I am having a similar problem but my car is sputtering around at part throttle.