Sniffle7

hey i just drove from florida back to nj, bout 1200 miles...i drove straight through. mainly the whole way at 3k rpms...and i noticed when i got back in nj that i was running a little richer then usual. so i didnt think much of it. now a day later...i noticed i was idleing at mid 11s.. and i usually never idled around that. and when im wot and the boost hits full boost, im in the 10s. and when i let off i go straight to lean. and if im at a crusie i can see my numbers hit 17-19...my meter even said lean. i never had this problem before...any ideas?

impactwrench

Vacuum leak?

Sniffle7

possible, im guna take a look.

XSTransAm

does the car feel any different? what kind of wideband are you using?

Sniffle7

i forgot the name when i get in my car ill take a look. the car sounds a bit different...i get some back fireing when i down shift. but thats it.

Brent 94

iTrader: (1)

I have about the same problem, idleing at around 11.3 AFR but only sometimes, car gets a lower tone to it when this happens as well, along with lower rpms at idle. It can't be good for the motor.....i was thinking that i have a leaky injector, because when i turn the key to start the car it has an error rich message(before i turn the key) and when the car starts up it starts at 14.3 and then lowers down to 12.2 when fully warm. The car usually idles at around 12.2(rich anyways) but in the low 11's is rediculous! I'm taking my car to Ray in a week or so, when he fixes the problem i'll be sure to let you know what he diagnosed. If anyone else has any thoughts that would be great.

Sniffle7

yea definately let me know, and xstrans im using plx m300...i pray its nothing serious. i hopefully will get my tools finally shipped up tomorrow, so maybe i can have a better look at things. but brent keep me updated.

afterburn27

iTrader: (5)

My car idles around 11.5 too, and that is with the airpump on too. lol Runs fine though.

I am running an rx7.com chipped ECU.

Sniffle7

^

Brent 94

iTrader: (1)

Yeah i'll be sure to keep you posted and up to date with what Ray says about my car, Is your car highly modified sniffle7? I'm hoping that it's something simple and nothing to worry about, but it's just scary to drive the car around when it's idleing at that A/F ratio because i know it's not normal at all and the fact that it's only sometimes kinda makes me think it's like a limp mode or something of the sort.

Sniffle7

yea its modified.

DigDug

Hehe, maybe you blew out some restriction/debris in a fuel line!

FWIW, your AFRs should read pretty lean at cruise, and should pretty much run off the lean end when you lift off the throttle. That's normal.

Sniffle7

i use about 10 oz of mmo every fill up, since the engine was born.(about 10k miles ago) so i dont think i had debris in the fuel system. i know its sapose to be lean when i crusie but i get really high numbers... like 18 and 19...even a warning message "lean".. and when i go wot im in 10s when i was normally round 11 and 12.

DigDug

I was mostly kidding about the debris in the fuel line...

How old is that wideband sensor?

Sniffle7

not sure previous owner had it in there when i got it. u think the sensor might be bad?

maxcooper

I wonder if it is related to the solenoid in the line that goes to the stock FPR. My understanding is that it is supposed to "hide" the engine vacuum from the FPR during hot starts. That would make the car run richer, since it raises the fuel pressure relative to the manifold (by hiding the manifold vacuum). The solenoid could be sticking or something, or the line blocked, cracked, or disconnected. To test this, you could wait until it idles rich and then yank the vacuum line off the stock FPR (I can't remember how accessible it is, maybe this test isn't really possible?). The mixture should become richer. If it doesn't, the solenoid might be bad. If this is the problem, you should be running leaner than before under boost, so be careful. This is a long shot, but something to consider. I am just trying to think of things that would change the mixture somewhat subtly.

Maybe it is a leaky fuel injector?

-Max

Sniffle7

thnks 4 input..its possible...

live2drive15

iTrader: (4)

The Fuel pressure regulator is extremely difficult if not impossible to reach without taking the UIM off. It is buried down by the LIM on the back side of the engine just above the trans. You may be able to pull the vacuum line to it, off but good luck getting it back on.

Sniffle7

my fuel pressure regulator is an aftermarket one and is located somewhere else.

Sniffle7

but either way im looking into the problem..its acting a little bit better. but still some noticable differences

maxcooper

Do you have any way to observe your fuel pressure (a gauge)? Perhaps there is a problem with the regulator or the plumbing.

-Max

Sniffle7

no i dont have a way 2, but i do notice some gunk or some kind of substance forming on the side of the regulator

maxcooper

Buy a cheap gauge and thread it into your FPR to see what is going on.

-Max

DigDug

Possible - widebands tend to start losing accuracy well before narrowband sensors. If you don't know how old it is, and it's not too expensive, might be worth replacing it just to know it's accurate. In fact, since you're getting richer readings on accel and leaner on decel, I'd start with that. Data is only as good as its source.

But if there was an actual change in how the engine is running, it's something else. Checking fuel pressure is a good idea, though you don't have a baseline to compare to (except factory, and who knows what you were actually getting prior to this, especially since you have an aftermarket FPR). Obviously you would be looking for an increase in pressure to produce richer AFRs on accel, but without knowing what pressures you were seeing before, a measurement now is only a sanity check to make sure you're not getting some crazy pressures and/or fluctuations. It's worth a shot if replacing the sensor doesn't fix the readings.

Sniffle7

yea thats what im about to do and replace the sensor. we will see what happens.