Unplugging the MAS and..... does this mean its bad?

[joeym4130]

Hey all. I have been thru just about everything concerning my idle problems. All the faq's, guides, advice, logs etc... anyways,
Prob is that my idle is really high around 1900, and really rich mix at idle, so rich that is misses a bit. But today for the heck of it I just unhooked the MAF electrical connector ....and as soon as i unhooked it, the car idled like a dream!!??!???? I detatched it, and idle went right down to 980 steady, no missing. damn, WTF? Does this signify a bad MAF im assuming?? Please let me know if this is a correct diagnosis on my behalf, thanks guys!!!

P.S., im not gonna drive with the maf unhooked just so u kno haha

 

[Lordpaxin]

its a good possiblility but there are still other options,

have you ruled out a boost leak>
if you have a boost leak, unpluggin the maf would end the ecu's ability to detect the extra air .and try to compensate, running it umplugged may just create a rich/lean situation.,

check for a boost leak,
then get a known good maf.

 

[joeym4130]

oh yah, shes boost leak free for sure first thing to check huh? haha. Hopefully its the MAF

 

[5150DSM]

Another thing you may want to check is the idle adjustment. What position is your BISS screw in? Are you able to affect idle by turning the BISS, and if so, to what degree. Also, I see you did the "free" mods, did this include hacking your MAF and aircan? Did you remove the large upper honeycomb, this can cause bad idle problems. Anyway, just some ideas, get back to us after checking and we can probably help more. Also, like Lordpaxin said, if you have access to a "known" good MAF, just swap them out for testing, that will tell you real quick if the MAF is bad. Good Luck!

 

[joeym4130]

HEy
Yeah i can effect idle using the BISS, but when i bring it down low its running so damn rich she starts choking and sputtering..i thought maybe the MAS was misreading and adding too much fuel. Its disgustingly rich when i idle it down, so i leave it up higher so it wont choke as bad. No, MAS is not hacked. Just aircan, got the car that way. Unfortunately i dont have access to a good known MAS, so i guess i'll have to get one and if it doent work just sell it, its all i can do.

 

[Lordpaxin]

i have 2 maf's

one is unhacked, and the other is JDM maf which if hacked from the factory

your choice

 

[crankbender]

Before you start just throwing parts at it check your O2 sensor and TPS. what are both reading when at idle with the mas hooked up?

 

[joeym4130]

Thanks for the replies guys!

Well TPS is reading 10.1% at idle, which i am told is correct reading off of a logger, should be around 10. Adjusting it lower then 10, gave me a CEL for TPS once, so i am pretty sure its right, ppl on here told me to set it for 10 on the logger.

Well, i think my O2 is good, i thought you get a CEL when bad? Maybe its slow. But noone can seem to tell me if it is or not. Its jumping around so im assuming its good. But this is reading at 1900ish RPM, where car runs rich but not rich enough to choke it.

Here is an ex.
time o2v RPM
21:24:11 0.55V 2031
21:24:11 0.31V 1969
21:24:12 0.06V 1969
21:24:12 0.43V 2031
21:24:12 0.14V 1875
21:24:12 0.04V 1906
21:24:13 0.31V 1969
21:24:13 0.53V 2000
21:24:13 0.55V 2031
21:24:13 0.29V 1906
21:24:14 0.06V 1906
21:24:14 0.27V 1969
21:24:14 0.55V 2000

what u think? good o2?