Could Old Sensors Change Afr's?

[ClutchBurndout-:(]

i was speaking to a mate over the weekend about my car running epic rich through mid range at 10psi boost on a stockish car (fmic, 3.5 zorst, airbox etc)

with the same mods in my last skyline i was able to run 10psi fine, but it runs way to rich in my current car so i have to run 7 or 8psi just for it to run smoothly through the rev range.

he suggested that maybe coolent sensors to the computer may need checking, since if its reading he wrong temp it will change afr's???

can anyone confirm this? or have any other ideas why my car runs way to rich at 10psi through mid range???

cheers

r33gtst, stock turbo, 3.5 zorst, fmic, airbox (no snorkel) stock timing (i think)

[MrStabby]

There are a whole bunch of compensations that the stock ECU runs, and they overlay extra fuel onto that which the fuel map specifies. Temperature is definitely one of them, and yeah it will richen the mixtures by a variable amount depending on temperature. (All IIRC). It would be worth getting CONSULT on it to check that everything looks normal.

[ClutchBurndout-:(]

There are a whole bunch of compensations that the stock ECU runs, and they overlay extra fuel onto that which the fuel map specifies. Temperature is definitely one of them, and yeah it will richen the mixtures by a variable amount depending on temperature. (All IIRC). It would be worth getting CONSULT on it to check that everything looks normal.

whats involved with getting consult to look at it? do all r33s have the consult cable in them? what is it exactly? ima noob with consult/software stuff

[mad082]

cars differ a lot between them, so you can't simply compare one to another. if you want to know what the ecu is reading as the temp, get a consult cable. it will tell you what temp the temp sensor is saying the engine is.

do you know for a fact that it's running rich? have you had it on a dyno, or are you simply going off the fact that you can't run as much boost? it may be that your old car had a weaker fuel pump (and was running out of flow), or your current car may need the injectors cleaned to get a better spray pattern to make it ignite better. the spark plugs, coils and ignitor (if series 1) may have been in better condiion on the old car. even the compression can make a difference. also i'd be more looking at the AFM being the cause of any richness issues that would be ecu related.

things like different brand intercoolers with different flow rates, boost gauges, possible slight intake leaks can all alter how rich the car runs because of restriction, variance in boost levels and the afm reading a different amount of air to what is actually making it to the motor.

[MrStabby]

whats involved with getting consult to look at it? do all r33s have the consult cable in them? what is it exactly? ima noob with consult/software stuff

You need a special cable and software, and it plugs into a grey plug next to the fuses under the steering wheel. Maybe you could loan it from someone in your area? Or ask a local nissan specialist workshop to take a look?

[mad082]

www.ecutalk.com or PM newkleer on here. i have one of the consult cables and they are great for looking at this sort of thing. i got the usb one so i don't have to worry about stuffing around with serial/usb adapters.

and yes all 33's have the consult port

[ClutchBurndout-:(]

www.ecutalk.com or PM newkleer on here. i have one of the consult cables and they are great for looking at this sort of thing. i got the usb one so i don't have to worry about stuffing around with serial/usb adapters.

and yes all 33's have the consult port

is there software i can get if i have the usb consult cable? and just play around on my laptop to see whats going on?

if i can where can i A get the cable and B get the software? to buy, as apposed to borrowing off members.

[ClutchBurndout-:(]

cars differ a lot between them, so you can't simply compare one to another. if you want to know what the ecu is reading as the temp, get a consult cable. it will tell you what temp the temp sensor is saying the engine is.

do you know for a fact that it's running rich? have you had it on a dyno, or are you simply going off the fact that you can't run as much boost? it may be that your old car had a weaker fuel pump (and was running out of flow), or your current car may need the injectors cleaned to get a better spray pattern to make it ignite better. the spark plugs, coils and ignitor (if series 1) may have been in better condiion on the old car. even the compression can make a difference. also i'd be more looking at the AFM being the cause of any richness issues that would be ecu related.

things like different brand intercoolers with different flow rates, boost gauges, possible slight intake leaks can all alter how rich the car runs because of restriction, variance in boost levels and the afm reading a different amount of air to what is actually making it to the motor.

do u mean internal fuel pump or external?

would injector cleaner work just as good?

would an electrical cleaner for the afm be a wise idea?

[jjman]

AFM could be involved in that equation but otherwise, from my experience, it would be the nature of your ECU.

Some seem to deal with more airflow n boost better than others...

My R33 couldnt even deal with standard boost before it richened things up for an epic flat spot up in the rev range!.

Ecu tune sorted it completely.

Not to say this is the case in your car but iv driven alot of R33's n they all seemed to be different and handle boosting differently... (or even standard boost in my case...)

[mad082]

is there software i can get if i have the usb consult cable? and just play around on my laptop to see whats going on?

if i can where can i A get the cable and B get the software? to buy, as apposed to borrowing off members.

www.ecutalk.com. download the software from there, it's free. also comes with the cable if you buy it (can buy cables off the site, or PM newkleer on here), along with a few other programs.

do u mean internal fuel pump or external?

would injector cleaner work just as good?

would an electrical cleaner for the afm be a wise idea?

either fuel pump. if the pump is dying then it won't supply as much fuel. or if the fuel filter is blocked.

injector cleaner won't really do shit. need to pull them out and have them professionally cleaned.

electrical contact cleaner is fine to use on the AFM as long as you are gentle.

[karma_syke]

i have a very similar story here, 33 with 11 psi boost, 3.5 turbo back, fmic,

i cleaned my afm with contact cleaner and that cleaned it up to near new, it was filthy, (had a crappy hks pod filter which filtered nothing, recently changed that to a 3a racing.) i also siliconed up my coil packs, which seemed to help with the flat spot, so check your coils.

i think my coil packs are on the way out maybe there not giving the spark plugs enough voltage for a decent spark, hence a crappy burn. if i change gear up in the rev range 4000 rpm + i will hear a pop from the exhaust. i seem to be getting worse fuel economy as well, i'm looking at 300km a tank now, i had a look at my O2 sensor and its got bosch written on it so i think its been replaced. so i'm not going to buy a new one.

the only thing left is to get consult cable + software to see what the computer is doing,

[ClutchBurndout-:(]

yea i get the popping to

my coils are splitfires so i think their fine

my panel filter is new

all thats left is to clean the afm, so im gonna do that tonight probly, i dont think its that dirty though

[ClutchBurndout-:(]

well, just ordered my cable and software, im keen to see whats going on with the car!

[mad082]

yea i get the popping to

my coils are splitfires so i think their fine

my panel filter is new

all thats left is to clean the afm, so im gonna do that tonight probly, i dont think its that dirty though

how old are the splitfires? none of the aftermarket coils seem to have quite as long a life as the genuine nissan ones, not even splitfires.

also how old are your plugs, and what gap are they?

[ClutchBurndout-:(]

how old are the splitfires? none of the aftermarket coils seem to have quite as long a life as the genuine nissan ones, not even splitfires.

also how old are your plugs, and what gap are they?

the splifires have about 20k on them?

plugs are pretty new to, gapped at 1mm~

[mad082]

i'd start with a professional injector clean. if you can pull them out and take them in yourself it should only cost about $30 each injector. a bit more if you get the workshop to pull them out (they are a bitch to do in the 33)