HC's and O2 was way too high. HC's in the 1500's


So, Im either burning oil or Running Rich, Or a combo of both.

Other than replacing the CAt w/ a brand new one, any other Ideas on getting HC's down ?

This motor is in my Blazer, and It runs well enough for me ( fiddleing around ofroad, getting me from here to there ) But I want to get ti registerd, and to Do so it needs to pass the E.

So any tips are appriciated. Thanks.

its an 85 S10, w/ carbie 2.8L

 

I would suggest new plugs, wires, dist cap and rotor; do a compression check, and check the timing. Poor combustion can nail you everytime especially on an older vehicle. Since it's carbed, isn't there an adjusting screw for the fuel ratio and one for idle speed?? Also double check all vaccum lines around the carb. Heck, even burn off a tank with gumout carb cleaner. Is your air pump operable/belts tight, those older pumps had a life span of like 5 years. You mentioned the cat, that is about everything you can do. Good luck!!

 

1500? Not bad. Almost keeps up with my car's 2200. :-D But that's due to a little mishap with the fuel pressure regulator housing... So now I dump way too much fuel into the engine. ANYways, you could try welding 5 cats in a series. heh. Standard stuff that will lower the emissions should help, such as making the car's fully warmed up (or overheating, the hotter it gets the the lower the HC's get), hell... If you get desperate, go to JiffyLube and get one of those engine cleaning kits done (50 bucks or so, not really worth it, but it could get you to pass...) It doesn't really fix anything in the engine, but your engine won't be burning gas, so the HC's will be lower. Run a mix of alcohol in the engine, that'd help as well.

 

i know how you feel, im going to get mine echecked tomarrow, i found taking the breather off majorily reduces hc, try that, maybe about 3 bottles of rubbing alcoholin a full tank of 93 octane in it. if you know how, retard the timing, and lean out the fuel mixture, that worked for me, and my car aint stock. good luck

 

I believe your problem stems from incomplete combustion. you did not make mention of the co and co2 but think that a tuneup like Lanccer mentioned would help. Also get the oil changed and spray a can of carb cleaner into the air bleeds and such. Make sure the air filter is in good shape. How old is your o2 sensor? I don't think your cat is at fault. I would also try some top end cleaner and water to make sure things are clean in there.

 

Usually CO is high when HC's are high. Both are from un-burnt fuel. Mine went down to nothing when I replaced my cat. Should have done it first and saved tons of time and effort...

 

My HCs were high while my CO was low and I installed a new cat, it lowered the HC some, but not enough. I would to a new cat only if all readings are very high.

 

what everyone else said, but i've been there before and the cat was the only thing that did the trick for me. had mine done for $140 installed (the cat was $100 at pep boys). not really that bad.

 

Here's what I'd do

pull the fan fuse and let her warm up good
retard timing
lean out the carb some

that should do it

 

heres what i did to my bosses corsica. he failed the first time miserbly and all i did was drive it through. today i had about 1/8th tank of gas and i filled the tank up with 5 bottles of dry gas, then filled the tank with regular gas. he was running pure alcohol and he passed. he was so happy that he didnt care that i had his car out for 3 hours instead of 1 hehe.

 

Check the vac fitting at the rear of the intake, behind the carb. The one that goes to all the vac acc. I belive. Should just be a single nipple (heheh)

I see these all the time split right at the intake. Runs perfect, wont pass smog.

 

I dislike those things intensly... along with the vacuum advance check the gulp valve and the diverter valve... they can cause serious vacuum leaks... what were all the gass readings??? high HC usually indicates a lean condition or ignition misfire...

zroc

 

dont feel bad, i just failed it, hc's and co, i am going to try a 2 barrel.

 

Nail on the head!!!

Car Craft sent their 305 in with a complete ignition upgrade (cause they knew it would need it later) and passed on 7 cylinders! Plus there is that stuff you can buy at car stores, Canadian Tire here, that sells 'gauranteed to pass emissions' goup. It would help!