How does a EFI motor run lean??

[bobtodd]

My plugs are white. Why would my car be running lean? 30lb injectors, 255lph Walbro pump, Kirban Fuel Pressure regulator. Newer O2 sensors.

Could the Turbo Blue I have been mixing in with my gas be causing the O2 sensors to be getting fouled up? I usually mix 50/50 with 93 octane. I have been suspecting that my car has been running lean for awhile. Maybe thats why I'm seeing smoke out my tail pipes now :rolleyes: I think my rings may be going.
Anyhow, how can I adjust how rich my car can run? I'm assuming I could crank up my FP a bit. I have been running it at around 38 with the vacuum line off. I was running it a little higher before but figured it wasnt necessary. The funny thing is, I just put the plugs that are in the car now a few weeks ago(colder plug for nitrous). The plugs I had taken out looked pretty good. Could a colder plug be doing something?
Any help would be apprecuated. Thanks!

[Jim]

i have heard that an msd ignition can make your plugs look lean too.

[quietflow]

Does your car use oil?

[Greg@GLD]

If you run the Juice, then you should be reading plugs often.
As far as bad rings, I dunno,- because then you would have oil fouled plugs most likley. Not white ones. I thought you ran a blower? You probably are leaning out if this is the case, get it on a dyno with a wideband 02 sensor and see what's what.

As for adjusting fuel pressure... that's a hack at best and the EEC will soon adjust the injector pulsewidth to compensate and bring the A/F ratio back to the tables determined by the EEC. The only true way to alter A/F ratio permanently is to use a chip or piggyback tuning device like a PMS or TWEECER or like in my case, an EFI Extender...

[bobtodd]

Does your car use oil?

Yeah, my car does use oil. I'm not for certain if it is the rings or not. I dont want it to be...lol. I have never had black plugs. The intake runners look like I am sucking oil through the intake though. While my heads are off I may just go ahead and get the valve seals changed and see if that helps any.

i have heard that an msd ignition can make your plugs look lean too

I do have a MSD coil and ignition box.

I would like to pick up an Extender. How well do they seem to work Greg?

[Greg@GLD]

I am happy with mine but it's "old school" and nowadays there are other options...

[bobtodd]

It may be old school but would it keep my car in the "safe" A/F ratio? Thats all I would really be looking for.

[bobtodd]

I would probably get a valve job while youre at it.

How much does a valve job cost?

[jdsgallops]

Where is Dave when you need him? he had a nice article on how to properly red plugs. Every EFI car I have owned has had white plugs, when reading them from "regular" driving.

[bobtodd]

I really am hoping I dont have burned up rings. It's not like the car burns oil the whole time you have your foot into it. Its the initial stomp on the gas that you see a poof of smoke. I may just go in and get the valve seals and and a valve job done. I called RPM and it sounds like it wouldnt cost much more than $100 to get it done. It's heaper than taking the block in. I'll see what that would cure and if it is my rings I'll just pull the motor later...after I've saved some money.

My plugs have always been a little white, but this time when I pulled the plugs the looked really white. I'll see if I can get a pic up.

[drag79stang]

For what it's worth, ANY amount of 'leaded' fuel will trash 02 sensors QUICKLY.
Takes very little, and the lead coats the 02 sensors, rendering them pretty much useless.
(FYI). (and they don't clean themselves out by just running unleaded again). :>(

[bobtodd]

No more racing fuel for me....:)

[SMOKD U]

sorry im late here but this is my view. you might be running lean because the injectors do not have enough pressure behind them. fix it by(t- rex or bigger fuel pump) or you are maxing them out. with my pms i can see how much paulse is left in the injectors and with 42's i was at 90% before my in line pump. now im at 70's just from that upgrade. plus everytime i had any vacu.me leak i ran leaner. if you have a dry kit make sure you have enough fuel. ps with race gas it is much more forgiving running leaner. do yourself a favor and get on a wide band to see what your air to fuel is. 12.5 is max and 11.5 is better. (12.5 more leaner and more power) i run 11.5 on the street and 12.5 at the track. i do notice a diff. good luck call me on my unleaded safe race fuel concentrate.