General running lean?

[dsmrocker]

o.k. How do i know if am running "lean"? my A/F guage stop working after i installed my new turbo(fpBig28). i mean it still does work but there are just 3 LCD working, so it stays on the lean side. my car runs fine. do anyone knows the problem? help pls. thanks

 

[candela]

Either get a new one, or get a logger... There really isnt a way to tell unless you have one of those to telling you. If your mod list is up to date, and you have an upgraded turbo, you definetly need more fuel. You dont even hae a pump or rewire and your running a bigger turbo (what boost?)...so my guess is your probably running lean...

 

[dsmrocker]

i'm a dummy i should have include this info. anyway, i also install a walbro 255hp fuel pump. with the turbo, i ported my manifold and 02 housing. i really dont want to buy a new one till i find out what is wrong. is it possible that it could be my 02 housing?
my boost by the way is set to 15-16psi.

 

[dsmrocker]

could it be my 02 sensor? i recall that i drop it on the floor when i was installing my turbo. it might be fouled or something. i called one of the local import shop here and they say that i probably running lean since i install the new turbo. but, how? i install a puel pump with it. now they said that they gonna charge me if i want them to check what the problem is. this is really bommin' me out. i never heard of someone who runs lean after the turbo installation, especially a relatively small turbo like the big28. but i could be wrong.
.....am going to the track today, and hoping that my car will still be in one piece when i get home.

any thoughts? thanks!

 

[BigBADGSX]

honestly i would try to replace your 02...im haveing the same problem lately......after my pump, and air to fuel gauge istall a long time ago ive been having this problem but i narrowed it down to my o2 so you might wanna try that then if theres still a problem your just gonna have to track it down! good luck

 

[lambertvr4]

You can use a multimeter to measure the O2 sensor. An analog one would be best so you could see the signal moving up/down while at idle. If it's oscillating at idle it should work under full load. Not that it's really gonna tell you much under a load besides "yep, leaner than 14.7" or "yep, richer than 14.7." You want it rich.

If your O2 sensor is bad then you will probably thro a check engine code. Maybe not tho. If it's not reading correctly you will probably be idling pretty rich and getting bad gas mileage.

You could check your plugs. If they are grey then you should be fine. If they're black then you're running rich. If they're white then you're running a little lean. Look all around the plugs for signs of detonation/preignition. The plug will have little spots on it that looks like a tiny ball ping hammer hit it. If you see this then you are in danger of hurting your engine.

Check your wiring and plug connections to the O2 sensor and the gauge. If that's OK, then swap out your O2 sensor w/ a used one. Hopefully the shop will have one laying around you can borrow or buy cheap.

Good luck.

PS- I'd highly recommend finding the source of the problem b4 racing. Better to wait and race next week than to race this week and have a blown motor. It's hard to hold yourself back, but you have to be careful. Play smarter, not harder!

 

[dsmrocker]

hey, thanks guys! these info will definetely gonna help me diagnose the problem. anyway, i did go to the track and just ran once, and had a 14.4sec. i know i could have done better if i raise my boost to 16psi and switch gear above 6000rpm(i did 5500). but since i'm a little affraid of blowing my car up, i decided not to abuse it. i was really happy about the result! thanks guys!