Ok Ive been battling this problem since the motor was put in. I know honda's run rich from the factory, but I don't believe that is the culprit here. Since the motor was put in. I have done numerous tune ups changing fuel filter plugs wires cap rotor distributor etc. Nothing has cured my large amount of smoke coming from car and the buildup on the bumper. I even had the car tuned p28 crome my a/f is in spec and that didn't help out with the black on the bumper. Only other thing I am thinking to try is a valve job? I want to try and get this under control asap because I'm going to be putting a fresh coat of paint on soon and don't wanna ruin that. The smoke I really only see when I get on it. at night if there is a car behind me when i get on it you can barley see the car anymore bc the headlights in the smoke lol. My bumper looks like this after about a week of driving (see pics below)

also some other issues I'm having with the car right now in case you need to know they may be connected are. Sometimes on a cold start if I don't let it warm up it will kinda hiccup while giving it a bit of gas kinda like a miss and then you smell a strong hint of gas. another issue is idle drops low at times when coming to a stop it will drop down to like ~400 rpms and raise back up to ~800.

Bumper after about week of driving:


Close up:

 

well **** thats horrible my car has same problem but it doesnt smoke as much as yours and my bumper never gets like that just a lil bit right above the tail pipe.but i would like to fix this running super rich problem my self im doing 19 mpg which is horrible for my 4 banger. if you get any intel please hit me up thanks.

 

im assuming you have an h22. look at any car with an h22 and exhaust. their bumber will look just like yours. its common, nothing to worry about.

as for the idle. take off the iacv and spray some brake cleaner threw it. that should fix your problem

 

I have the same prob with mines, atleast the gas mileage problem. Stock h22a1, I/H/E (came on car, just replaced some items here and there). Stock ecu, EGR still connected, running 93 sunoco. I haven't measured it, but my old civic with a modded b18c running pig rich would get better gas mileage than this. I notice the hiccups @ idle as well (kinda like a weak backfire). Sometimes on deacceleration I get a pop or two (or sometimes more like a popcorn machine =/ ). Maybe it's egr related (clogged?). Also, no codes are being tripped.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AmauryR &raquo;</TD></TR><TR><TD CLASS="quote"> I notice the hiccups @ idle as well (kinda like a weak backfire). Sometimes on deacceleration I get a pop or two (or sometimes more like a popcorn machine =/ ). Maybe it's egr related (clogged?). Also, no codes are being tripped.</TD></TR></TABLE>
good description of the hiccups thats about exactly the same as I get on some cold starts. Rule the egr out. I removed egr all together got euro-r intake manifold and blocked off the runners. still acts up.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ilikehonda &raquo;</TD></TR><TR><TD CLASS="quote">im assuming you have an h22. look at any car with an h22 and exhaust. their bumber will look just like yours. its common, nothing to worry about</TD></TR></TABLE>
Yes h22. I have seen other preludes running rich but not this bad. If you could please explain the reason for this better I would appreciate it? I would figure there would be a reason behind this?

and as far as the iacv I have cleaned that thing plenty of times. replaced gaskets. I believe i narrowed the iacv out for that issue as to the fact it does not do it all the time and not at idle. only when coming to a stop.

 

the h22's just run rich. that is how they are tuned from the factory. im assuming to get rid of any knock. if you have checked the iacv check the fiacv and all of your vaccume lines

 

Not trying to be mean but did you read my whole post?
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M2B4 &raquo;</TD></TR><TR><TD CLASS="quote"> I know honda's run rich from the factory, but I don't believe that is the culprit here. I even had the car tuned p28 crome my a/f is in spec and that didn't help out with the black on the bumper.</TD></TR></TABLE>
its not on the factory tune. FITV has been removed. All vacuums on intake are fine and intact. Checked over everything when installed the brand new euro-r. So in recap IACV cleaned numerous times and replaced gaskets. FITV removed. no EGR system. EGR ports clean. All new vacuums ran for intake.

 

Well damn that sucks, glad my car isnt white ;o

 

well you must have a shitty tune. im tuned on a p72 with hondata and i dont have that problem. after a night at the track i might have a bit of black on the bumper but no biggy.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ilikehonda &raquo;</TD></TR><TR><TD CLASS="quote">well you must have a shitty tune. im tuned on a p72 with hondata and i dont have that problem. after a night at the track i might have a bit of black on the bumper but no biggy. </TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ilikehonda &raquo;</TD></TR><TR><TD CLASS="quote">well you must have a shitty tune. im tuned on a p72 with hondata and i dont have that problem. after a night at the track i might have a bit of black on the bumper but no biggy. </TD></TR></TABLE>

I'm glad this thread is about your car and your problems. If you cannot add any useful information please don't add any at all. Any one have any technical information that may be useful to my issue?

 

I have the same problem and done the same things you have done. But nothing helps get rid of the black buildup either. bump for more info!

 

well I have the same problem, but my problem is Cat. related and all it needs is to be replaced.

 

I know you said that your AFR was within spec...what was it reading throughout the full rpm range ? what time of year did you tune it ? Have you ever changed the oxygen sensor ?

I had a white civic with a built sohc and it was tuned with a p28 on crome and it always turned my back bumper black...The AFR's on it were around 14/1 when cruising and as it went into the powerband it ran around 12/1....

 

AF was pretty linear just under 14 most the way through high rpms. I dont have partial throttle AF numbers just full throttle. I replaced the O2 sensor shortly after the swap thinking that was the problem. It was tuned in Nov. Anyone else got any ideas?

 

well your af is pretty decent. is your knock sensor turned on of off? but like someone else said you a/f may be off at partial throttle. you should maybe do some partial throttle tuning and see if that helps.
btw its not my car that has the problem its yours. if you dont like what i have to say then please ignore it.

 

are you burning an inordinate amount of oil?

 

I sometimes get that idle bounce at startup too but it goes away after a bit. I also have i/h/e w/out tune and my car feels/smells like it runs real rich. I'm guessing a lot of ludes have this problem

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bluedlude &raquo;</TD></TR><TR><TD CLASS="quote">are you burning an inordinate amount of oil?</TD></TR></TABLE>
I wouldnt say I burn a good bit more oil than normal. use a qt inbetween changes.

The smoke issue is at full throttle not partial. I will keep that in mind but dont believe it is the main problem. Any one else got any ideas or advice? Debating over getting a valve job dont really like any local shops here.

 

anyone? anything?

 

a quart inbetween changes is alot especially if your smoking at high rpm, valve seals, rings, could be bad. do a compression and leakdown test and find out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AMeg6 &raquo;</TD></TR><TR><TD CLASS="quote">a quart inbetween changes is alot especially if your smoking at high rpm, valve seals, rings, could be bad. do a compression and leakdown test and find out.</TD></TR></TABLE>

Sounds right, start with the basics again. Sometimes it's something that was overlooked.

 

motor was compression tested after installed. Cant remember exact order but was 200 - 200 - 210 - 200. Never did a leak down test on the motor, but Ive been hearing a lot of noise coming from valve cover. Guess I need to look into shop reputable shops for a valve job try that out.

 

id do just the valve adjustment before... a valve job isnt going to keep the valvetrain from clicking

 

yeah Ive been putting off doing the valve adjustment my self. Cold weather and all. Before looking into the seals Ill get compression retested to be sure. Don't know if this is a dumb question but logically thinking adjusting the valves if they are out of spec will mess with current AF and effect tune?