Running too lean?
 

Hey guys,

Any clue how I can tell if I'm running too lean? Is it normal to have some black soot on the exhaust tip? Just wondering if this is caused by running too lean.

Thanks!

that would actually be caused by running a little rich! the real way to tell is get dynod and check your AFRs.. or installing a AFR gauge

Thanks Terrible! From what your saying the black soot is from running too rich, would this cause like moisture dripping out from the exhaust as well? I believe it's water, not sure.

Did some searching on Google and people are recommending to solve the issue with running too rich I should replace the spark plugs. Think this would do it?

Did some more searching and people on the forum are saying it's normal for the 370z to run rich. Guess I'm stuck with the dirty exhaust tip.

You could do some breathing mods to lean it out a little bit :driving:

:ninja3:Water is a byproduct of good combustion as well as condensation in the pipes

Would a new exhaust system help? I do have ART pipes right now. Guess this gives me a legit reason to upgrade lol

Thanks for the info Felix good to know that nothing is wrong or damaged.

I've noticed this same problem ever since I installed my HFCs a month ago. I never used to have the black soot on my exhaust tips before when I just had my CBE and intakes. I guess I'm running too rich with all my mods.

Theoretically, YES! :tup:

Yeah I think were on the same boat, looks like it's time to upgrade the exhaust system.

Planning to get the Motordyne E370 :happydance:

Oh I don't have any CATS on could this be a factor as well? I plan to get CATS on the exhaust system, feel bad polluting more then I have to

I have some black residue on my stock exhaust. Car is completely stock for now. Maybe it won't happen when I get my CBE.

Well I have already upgraded my exhaust (CBE, intakes, and HFCs installed) so I will need a tune to fix it.

Carbon deposits. You can't tell from your exhaust tips if it's to lean. Carbon is the black residue left over from the burnt fuel. With 10-15% ethanol used in most fuel today, it leaves a black carbon residue which is collected at the exhaust tip or exit. Every automobile today will have this residue.

You need to run a spark plug chop test and actually look at the base of the spark plug insulator with a magnifying glass. If it's really dark brown or black you're running rich. If it's really light tan, light gray or chalky white you're lean. What you're looking for is; a medium to dark tan. You can install a A/F Gauge but it's readings are more relative to the climatic conditions.

If your running an intake, headers, test pipes or HFC's, cat back and improved intake manifold you might be a tad lean, possibly. If not, there's no way the ECU will allow a lean condition.

Another way to tell is to pick a specific gear 2nd-4th, hold a specific RPM at around 3700-4000 and see if the Z surges slightly. You'll know exactly what I mean if you feel it. If it does, then it could be an indicator of running lean. You will also develop a lean "POP" under deceleration in every gear but will be progressively louder under higher rpm load in lower gears.