90 civic high hydrocarbons

I just put my car through Aircare(emissions testing) and it passed everything exept for reading high on hydrocarbons on the idle test. Does anyone know how to bring these numbers down. It's a 1990 civic with the 1.5 litre, 245,000 kms. New sp-plugs,fresh filters(air-oil),new muffler and new oil.

I just put my car through Aircare(emissions testing) and it passed everything exept for reading high on hydrocarbons on the idle test. Does anyone know how to bring these numbers down. It's a 1990 civic with the 1.5 litre, 245,000 kms. New sp-plugs,fresh filters(air-oil),new muffler and new oil.

Wow 245k Hc's are raw fuel, so it could be...

Purge canister full
leaky inj
Fuel pressure reg

O2. See if it is baised lean
I think 90's have map sensor, check all vacuum lines. Yes, some can cause rich cond
Coolant temp sensor
octane in fuel, for emissions run low grade (unless specified) 87 burns easier that 92.

How bad is it? are you way over the limit or close?

SH

i had the exact same problem. i adjusted the valves and fuel filter and then passed with flying colors. also go to the coquitlam aircare on united blvd. I never fail there. also change your oil. it never hurts.

Max allowable HC's are 116 ppm. My car read 157 ppm. It's not extreme, but it's enough. Thought maybe the o2 sensor! Don't have alot of money to spend on it,or time, so any easy fix's! also has new fuel filter

my car read around 260's when i failed. and went down to 30 when i passed. adjust your valves. its easy, free and only takes about 20-30 min

also you could put a 1L bottle of methal hydrate into a half tank of gas. thats an old trick.

I've never adjusted valvles before.Are there any quick tips. btw, thanks for the reply.

if you've never done it before, just get a manual. all you need is a 10mm wrench, a flathead screwdriver and some depth guages. i cant think of any tips its pretty much how the manual with describe it. good luck.

adjusting valves...I wouldn't think that would make that much of a difference as far as HC goes. I would work more on the fuel managment system, go with the O2 sensor and work your way up from there. Also since it's at idle you might want to clean out your idle air control valve, if it doesn't help it's good maintaince anyhow. Also see if you're throwing any codes from the ECU..I was able to pass california emissions with an error code but it was way close, if you're throwing codes you'll burn rich.

if your exhaust valves arent to spec then they could be letting unburnt gas into the exhaust giving you a high HC reading.

How do i retreave the codes!

it's under the carpet in the passenger foot well...unscrewed the huge plastic screw things in the carpet, pull it back and there the ECU is...there's an LED in the middle of it, turn the car in the ON position and it should blink once to show it's working, if you see it keep blinking then count how many times it blinks and tell us.

I did what you said and it only blinked once when i first turned the ignition on.It's not giving me anything else,which i hope is a good thing. I never knew it existed. I'll try replacing the 02 sensor and go from there. I just don't want to keep running back and forth to aircare at 23 bucks a pop! Btw where is the idle air control valve?,and thanks for the help so far.

the iacv is on the back of the mannifold to the right of the throttle body. its got 2 hoses connected to the underside and is held on with 2 12mm scews. I was told to spray this unit with brake cleaner or degreaser, i guess u just have to watchout for the wire connector on the side. Ah shit if its a dpfi manny then i am probably wrong about its location, and hopefully someone here will let you know(sorry). G/L

Buy a little red bottle of RxP.... i did a tune up and added a bottle, ran it for about 60miles and my numbers were cut in half.

Is RxP available in canada. If so where do i get it. I've never heard of it.

yes your computer is running fine then, do you have catalytic converters on your cars in canada? sorry if that seems ignorant I'm just really not sure. Try adding a bottle of the sure to pass kind of stuff to your tank from your auto parts store, that can usually get the numbers down enough to pass, and you're close enough that it might bring you low enough...O2 sensor is a big deal if it hasn't ever been changed, I gained almost 5mpg from changing it which shows my car was burning way rich. if you're not sure where it is it's near the bottom of the exhaust manifold with one wire going to it, I had to fix a few wrenches together to get it out it can be pretty stuck, you need leverage.

Here's a link to their site
http://www.rxp.com/whereto.htm

I'm pretty sure the o2 sensor has never been changed, better mpg would be nice because it really sucks right now.Gas up here is at $1.12 a litre so any little bit helps. i'll post and let you know what my numbers were when i get a chance to work on it. Thanks again.