9krpmrx8

iTrader: (46)

Okay, I am having a bit of fuel in my oil per my UOA so I was reading some information and discussions about injector nozzles becoming larger from the high pressure flow over the years. This supposedly leads to a larger nozzle and more fuel but It does not seem likely to me but I thought I would get your thoughts.

dannobre

iTrader: (3)

More likely it's the pig rich AFR that the stock computer thinks it needs at high RPM......coupled with too much in town driving and not enough track time Leads to fuel in the oil

Change oil...go to track....that is all


PS: the " nozzle wear" issue is easily corrected by fuel trims

9krpmrx8

iTrader: (46)

Thanks you sir! I am patiently waiting for warm weather track days.

P.S. I am logging with the Hymee live and when my cars backfires at high RPM the AFR gauges pegs into the red. Should I be worried? My car is running perfect though.

nycgps

iTrader: (1)

you worry too much ...

@!!narotordo

Dang. That sounds like fun . Tune up and hit the track. If my 8 checks out ok, its track time.

olddragger

iTrader: (3)

all is true ----except. the injectors do get dirty. if you have 50K or more miles on the injectors it MAY be time to remove them and send them off for cleaning and balancing. you may be surprised at the findings. I was.
Then reinstall, change the oil and drive the **** out of it.
OD

9krpmrx8

iTrader: (46)

Yeah my injectors have over 100k on them (unless during the two engine swaps they replaced them, but doubtful). How hard on a level of 1-10 are they to remove OD?

MikeTyson8MyKids

iTrader: (1)

This is right up my alley. I do work very similar to this for a company that designs and builds OEM fuel injectors for a competing Japanese car company. I run some life and durability tests along with testing parts that come from customer cars.

It really is surprising, even say after 100k miles, how little these injectors change in spray pattern and flow. Its borderline statistically verifiable, especially injectors that are the needle valve underneath the form plate design (hardly any pentel-style injectors anymore).

But like olddragger said, none of that means anything if you hve some deposits in the filters or on the form plates.

How do you "balance" a fuel injector? Trade some out for ones that flow t the same rates (matched pairs)? Just curious.

9krpmrx8

iTrader: (46)

Yes, I do


Thanks for the input.

@!!narotordo

Yeah OD spill the beans

paulmasoner

iTrader: (1)

pretty sure what OD is reffering to is flowmatching. flowmatching is just that, thw flow rates of a pair of injectors are matches as closely as possible. in OE condition your injectors may vary in flow by surprising percentages, flowmatching makes them flow evenly. this usually shouldnt ever be an issue for an NA car, and the PCM makes corrections for errors in total flow via trims. But for FI folks, especially depending on the method of tuning, this can b a great aid in making fueling transitions smoother and tuning more precise.

FWIW when i head back down the FI road again, my P1, P2, and secondaries will all be flowmatched pairs

olddragger

iTrader: (3)

Thank Paul--you said exactly what i was thinking. Remember everyone I am old school!
My injector were removed (not hard to do 9K--maybe a 3) and sent off. One injector was atually having dribbing--lol. None were within 5% of the other. A good cleaning (ultrasound etc) and matching fixed me up. Methinks premix may have something to do with it--and the dirty Ga gas we have.
Just like Paul said on a na car the ecu can compensate in an overall manner. But it cant differenuate between the front and rear rotory. One rotor may be running lean and the other one rich but they can kinda balance each other out by the time the exhaust hits the a/f sensor.
For a street driven car it would probably never be a cause for concern. But if you road track and keep a high rpm level going for a while--then it may be something you will want to think about.
And again just like Paul has said--if you FI then this is one thing to do before you finish the install!
OD

9krpmrx8

iTrader: (46)

Hmmmmm. Where did you send yours and how long did it take? With over 100k on mine I sure would like the peace of mind.