running rich

[1PhatCX]

alright, just curious on how i can lean my car out
i just bought an a/f ratio gauge and its running really rich, even on idle. so i need 2 know how 2 lean it out some to make it better
all i have done is an intake, a crank case filter, ngk plug wires, and the exhaust, those are the only really big mods

any help would be good, expecially if i dont hafta buy anything lol

oh, and i'm running on normal 89 octane gas (regular)

[2ndb18]

ya my car has been runnin rich lately too. It smells rich and i have an exhaust leak so you can smell it all the time.

[SiZ]

They're all rich!

Rich - okay, Lean - baaaad.

Your A/F guage is probably way off too. They're not acurate worth a shit.

[JimCRX]

maybe o2 sensor?

[1PhatCX]

Originally Posted by JimCRX

maybe o2 sensor?

nope, i put a new one in there about 8 or 9 months ago, and it was running rich right after that too, and before it, i went thru 4 o2 sensors in 2 days and it kept running rich

[src21k]

just leave it rich its going to hurt you more if you end up making it to lean. Better be safe then sorry

[1PhatCX]

ya but its way TOO rich, i need 2 lean it out a bit, this things eating gas badly

could it be the injectors are too big or something??

[FourthGenHatch]

Did you tap your O2 sensor wire to get the A/F reading? If so you just fucked up your O2 because now it is losing voltage because it has to send a signal to the guage and also to the ECU. If you want an accurate A/F reading you need a wideband O2 sensor.

[krustindumm]

you can get a ccurate reading from a narrow band sensor, but only in a VERY narrow band. Here is a pic I made to show how the narrow band curve is:

[1PhatCX]

Originally Posted by FourthGenHatch

Did you tap your O2 sensor wire to get the A/F reading? If so you just fucked up your O2 because now it is losing voltage because it has to send a signal to the guage and also to the ECU. If you want an accurate A/F reading you need a wideband O2 sensor.

i tapped it into the o2 wire but its the piece of wire going from the ecu to the connector just before the o2

thats what it said to do, and whats a wideband o2 sensor? and where do i get one?

[travagliante]

NO YOU DO NOT WANT IT TO RUN TO RICH!!!

sorry for the caps, mine is running way to rich and basically it destroyed the engine.(blew headgasket, caught oil on fire, etc. etc.)

[krustindumm]

a wideband is a special O2 sensor that requires a special circuit to control and interpret it's readings. They run $300+ for the whole setup.

-Dustin

[krustindumm]

First I would try resetting the ECM and then letting it relearn everything, maybe one of your sensors as waivered out of spec since the last time the ECU has been reset. I highly doubt this will work.

If you want, you could get some injectors from a 1st gen CRX/civic si, they are slightly lower flow and will lean it out unless the ECU relearns it.

Though my best idea is this, ignore your A/F gauge.

A O2 sensor is basically a battery, at any voltage you can only get a specific current, to get more current, the voltage lowers. When you add a gauge, the current increases, the voltage lowers, the gauge will show rich until the ECU leans the engine out until it sees the normal stoich voltage at which point your engine will run lean.

To fix this, add a O2 sensor that is JUST for the gauge, either have a bung welded to your stock mani, or buy a header w/ two bungs already. I recomend the later, and get a 4-wire sensor, they are heated so you will get readings immediatly on startup, and this will become very important when it is mounted further from the head.

[Hilikus Funkin]

my friend has a crx hf that he put an LS ecu into and he had also put a d16a6 head onto it. He said after he put the LS ecu into it he got tons of fuel but it was worth it because he said it just launched for a single cam. BTW hes used to driving a 98 Prelude. So im thinkin of doin this, hes been begging me to put it in for a while and i think im gonna let him.

[Hilikus Funkin]

Oh yeah and A/F ratio guages are bullshit to me. My friend has one in his Teg and all it does is go back and forth.