Lil Corb

I recall that it can depending on how much it is out of spec. I have seen it where a obd2 ecu will throw a code for being too rich or too lean if it really out of spec. Usually that happens if the car isn't completely cold when doing valve adjustment. I'd say it is possible.

M2B4

kinda bothers me thinking that b/c I drove 3.5 hrs for the tune. lol

apt_lude

I have the same problem with my 5gen...I've got a JDM H22a/M2B4

Haven't found anyone that can help me with the problem, I was thinking it was maybe my IAT sensor? since I didn't have one...Found out the EGR system wasn't hooked up, (I bought the car used) hooked it up, still have the same problem...I've got a mugen exhaust and header just waiting to be put on but I don't want to taint them with this black stuff

plikit

i have a similar exhaust problem, except i do use extra oil... AND my idle is solid.. BUMP for help.

Sam_J

Having a White car makes it 100x worse too
I also deal with a yellowish blackish haze on my bumper.. I imagine running a wideband O2 all the time would help.. keep everything accurate?

eric416

I just started having the same problem but only started noticing it after I got a cel #1 (heated o2 sensor). I'm gonna try and change it and let you know if that helps. I bought a bosch o2 sensor but had trouble getting the old one off my headers. I'll report back after it gets changed.

kevin22trac

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam_J &raquo;</TD></TR><TR><TD CLASS="quote">Having a White car makes it 100x worse too
I also deal with a yellowish blackish haze on my bumper.. I imagine running a wideband O2 all the time would help.. keep everything accurate?</TD></TR></TABLE>

Don't feel bad i have a red one and i have the same problem with the whole black smoke and i don't hit V-Tec that often as well if i could make the problem go away i would feel alot better just because it looks bad. But it does use a good bit of oil, a friend of mine also said that the smoke is fuel build up, but if thats the case it seems to me that is using alot of extra gas and with the way gas prices are i don't want that.

PreludeJunkie

Hello,
I have the exact problem with my car, BB6 H22A4. One of my friends works at a shop and a regular customer of his had this problem as well, he was told to change his PCV Valve. Now he says it's all fixed and runs perfectly fine, not burning any oil. It might be a long shot but I'm gonna change mine out today and see if it helps or not. If not then it's my valve seals or rings.

dartonh22

just along shot but if your exhaust is not positioned right, as in it does not stick out from the bumper far enough it will produce this black reisideue on the bumper, my car is pretty bad too, i have it tuned with hondata, dont know if its real rich or oil but i know if i run the car by a wall it will shoot black **** all over it, but the car doesn't smoke. idk

incubus

I have the same black smoke problem with my prelude I have started to mix 87 and 93 octane (like 40/60 mix) and I get a lot less black buildup, so I guess the black buildup is hydrocarbons (unburnt fuel) also someone said the exhaust doesnt portrude from the car enough, that is correct. remember cars have a negative vaccum bubble following them in the rear while driving, so a great deal of the exhaust gas is trapped in that area while driving.


Modified by incubus at 8:22 PM 4/6/2008

ilikehonda

h22's run rich and burn oil in vtec...........as stated 23643987 times

M2B4

Just so you all know I havnt fixed my black buildup problem. Im sure theres an issues somewhere with the fuel i got my record high so far with mpg today lol 19 MPG!!! was 17 last week....

19 mpg @ $47 a tank is starting to suck lol

Acidcrakker

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M2B4 &raquo;</TD></TR><TR><TD CLASS="quote">Just so you all know I havnt fixed my black buildup problem. Im sure theres an issues somewhere with the fuel i got my record high so far with mpg today lol 19 MPG!!! was 17 last week....

19 mpg @ $47 a tank is starting to suck lol</TD></TR></TABLE>

Start taking the bus.

Thats where my MPG is around as well. But I drive very harsh city condtions. I might leave the car idleing in neutral for about 20 mins a day. I have minor carb build up on the muffler, but I spray it down with carb cleaner once a month to take care of that.

no1knows908

Have you all you OBD1 guys checked your timing yet?

TylerC161

Okay. I've got the same problem as well. Except the back of my car looks like it would after you drive in the rain for a while. Its the light brown gunky **** all over the back. I'll go snap some pictures here in a little bit.

Though reading this thread is interesting. Many of you are mentioning o2 sensors and such, I just want to chime in and say none of mine are hooked up. I'm running a h22a with a m2b4, i/im/h/e, I burn/leak about 1 1/2 quarts between changes. I've got oil leaking down to the spark plugs; thats getting fixed tomorrow. My current gas MPG is ~10-14 depending how much I hit VTEC. I'm also going for a retune since the last one was in november. Its very obvious that my car is running rich, I just dont understand why. Because I'm running a chipped and tuned p28, the maps shouldnt of changed. I've got my EGR removed, as well as evap and all that other bs. I'm running the s2 manifold, still have my iacv hooked up, though I plan to remove. I've had the lumpy idle in the past couple weeks when it was colder as you all described.

Sam_J

try seafoaming too, theres a thread aorund here somewhere explaining it

98vtec tuned my car, and it isnt anywhere NEAR as bad as it was before.
I don't even have my O2 sensor turned on and I get 23-25 mpg

to all you guys that run a custom or chipped ecu:

GET IT TUNED

konartis

same problem here people. It isn't that bad for me but it still happens.I haven't really addressed the problem because it's minor, but who wants black **** on their bumper? I changed out the oxygen sensor last year because the part came with the car. I cant remember why the previous owner had a new o2 sensor but didn't install it. Anyways I have a helms manual that has an awesome grid table showing you the first things to look for if your having problems with bouncing idles, problematic cold starts etc. Im going to do my best to get that up for you. It probably wont look that great from a digital camera.

A Blue Lude

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M2B4 &raquo;</TD></TR><TR><TD CLASS="quote">I dont have partial throttle AF numbers just full throttle.</TD></TR></TABLE>

Part throttle is of course what matters, since you're at it most of the time.

Of course it's could very well be fine.


Modified by A Blue Lude at 11:08 AM 4/8/2008

konartis

I got a pdf file on my pc with the page on idle control systems. How do i post it on here?

M2B4

make you an account at photobucket.com and upload the image on that. then copy the link for the image and paste it in your post and it will show the picture.

I am in the process of trying a few things right now. just filled up 2 days ago gunna wait and see how my mpg and rear bumper look in a week then i will report back.

civicminded93

Im in the process of getting a 2000 honda prelude, it is running rich, We can tell by the exhaust coming out, and the air fuel ratio gauge. what can be causing this? would new sparkplugs help?