Earlier today I had my car tested to pass smog here in california and the guy said it had to much co2 and his thought was that the car was running rich. My carbuerators fuel mixture is at factory setting and it seems like all my vacumm hoses are in good shape, new EGR valve....new plugs..wires...timing is on..new tps sensor...and my mind is at a blank at what could be making my car run rich....im not getting any SES lights so any suggestions or anything at all would help...I need to get my car to pass within the next few days...

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1986 Pontiac TA 305 carb.
K&N Open Air Cleaner
B&M MegaShifter

Future Mods:
3.73 gears
Nos
TransGo Shift kit
Edelbrock Perf. Carb.
Edelbrock RPM manifold

Cool car for being my first and spending $1000 at an impound auction. Had to start it with a screw driver for a bit but it's all gravy.

 

hey i had/have the same problem, i too live in california. so your running rich you say? when i first brought my car in it failed hydrocarbons and co2, but passed nox. i changed my cat, wires, plugs, cap & rotor, oil and filter, o2 sensor and used numerous fuel additives. i drove my car around morning before i took it in to smog the second time to get the cat as hot as possible so it would burn off the stuff asap. after i took it back the problems were fixed, but then another one sprang up (nox). it no longer ran rich after doing what i did. have you checked your o2 sensor? before you take it back in change your oil becuase the old hydrocarbons are stored in the oil. hope this helps

 

Yeah to go into more detail, I do have a new 02 sensor in.....it fails at higher RPM....it passes at idle....but at high rpm it fails because of to much co2...its at like 170 and is suppost to be at 130 or something...would having to much hydrocarbons cause it to fail on co2?....thanks for the help.

------------------
1986 Pontiac TA 305 carb.
K&N Open Air Cleaner
B&M MegaShifter

Future Mods:
3.73 gears
Nos
TransGo Shift kit
Edelbrock Perf. Carb.
Edelbrock RPM manifold

Cool car for being my first and spending $1000 at an impound auction. Had to start it with a screw driver for a bit but it's all gravy.

[This message has been edited by Mr. TA (edited July 03, 2001).]

 

im not a pro at this by any means, im sure that someone else will come along and be able to tell you just what is wrong with your car, but i do know that if your car fails hydrocarbons its running rich, if it fails co2 its misfiring, if it fails nox its becuase of high temps in the combustion chamber and also from running too lean.

 

make sure your smog pump is working,and if so its converter time.if it isnt there(skypart!)then there you go.the smog pump pumps extra air into the cat to help it burn all the stuff better(more air=more fire=less emissions)
im sorry you live in cali,here where i live theres no emissions(telling cop,yes sir it sure does have a cat yes sir its all stock exhaust lol)

 

oh yeah mabye the mixture control solenoid in the carb is half stuck...usually when its that the car runs like poo though..
just some thoughts
mike

 

Check air injection, is it working??

Check the vac. hose coming from the charcoal canister. Is it full of gas?? Is the canister full/heavy??

Do you have access to a DVOM??

How does it run overall??

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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

 

To go into detail on how the car runs.....it does hesitate sometimes at the begining....my carb has been rebuilt and has hesitated ever since I bought the car....the idle is somewhat rough but passes smog at idle, just at high rpm it fails as i said before. How can you tell if your smog pump is bad?...and if its bad is very hard to replace?......anyways thanks for the help.

------------------
1986 Pontiac TA 305 carb.
K&N Open Air Cleaner
B&M MegaShifter

Future Mods:
3.73 gears
Nos
TransGo Shift kit
Edelbrock Perf. Carb.
Edelbrock RPM manifold

Cool car for being my first and spending $1000 at an impound auction. Had to start it with a screw driver for a bit but it's all gravy.

 

How's your air filter? If it's dirty, your car doesn't get enough oxygen, and your CO's go up.

Here's a quick breakdown, from when I did some reading on emissions to prep myself for NJ's new "Dyno" emissions test:

High HC and high CO: Running rich
High HC and normal CO: Running lean

High NOx's are tricky. They're a result of high temp and high pressure- the same stuff that engines use to make power! That's why the EGR's around; when it lets exhaust gas back into the engine, it cools the "explosion". However if you're just getting measured at idle, your cat convertor could be acting up.

High HC, in general, means your car's combustion cycle isn't completing. The timing could be too far off, or you could have a misfire. Supposedly, one misfiring cylinder creates enough emissions to equal that of 10 "normal" cars!

You didn't mention air filter, so that might be it. I don't know how much you changed on your engine to get the open-element filter on there, but if you have the stock parts lying around, throw 'em on, and put a cheap $6 K-mart air filter in just to pass the test. I've got one of those K-mart "emissions test" specials in my basement.

[edit] Figured I'd add, for any NJ guys reading this: The new emissions test scared the snot out of me; until I read that about the "one misfiring cylinder". I passed emissions so cleanly that my mechanic was impressed- I wish I asked him for the printout, but I was so happy I just wanted to get the heck out of there! All I did to prep for my emissions test was: New K-mart air filter, removed ADS chip and put back the stock GM chip, removed 160 stat and put in 195 stat, cleaned inside of distributor cap/rotor from carbon tracking, sprayed "TB and intake cleaner" into throttle body, and the weekend before the test, I dumped a bottle of G2P "Guaranteed to Pass" in a full tank of 93 octane.

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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

[This message has been edited by TomP (edited July 05, 2001).]

 

One thing that is mentioned above is important for emissions. Re-install your 195° thermostat if you have installed a lower temp. Emissions is about the only thing the stock stat is good for.

As for the stumbling consider checking the distributor pickup coil.

PS.... my 85 LG4 had no SES light either because the bulb was burned out. Don't trust the SES light. Check your codes with an Auto X-ray. If you have a code 15, Coolant Temp Sensor, out it will keep your car from going closed loop, enrich the heck out of your mixture, and prevent TCC lockup.

A lot of "wreaked havoc" for a $10.00 sensor.

[This message has been edited by MikeInAZ (edited July 05, 2001).]

 

Would a aftermarket cat-back hurt emissions? Here was my test readings:
HC
reading - 12.00
standard - 1.40 fail
CO
reading - 91.80
standard - 20.00 fail
NOx
reading - .69
standard - 3.00 pass
CO2
reading - 496.7
standard - n/a pass
This was before a full tune-up but i didn't think i would fail that bad.

 

Looking at those numbers you're going to need a new Cat. Summit sells Catco converters for a good price. I would also try leaning it out a bit. My car failed badly on HC and CO as well and no amount of tuning I tried made much difference. Using Dry Gas in the tank and running it leaner I got HC close, but CO was still way over. A new Catco cat (3", $99 for mine) put me wayyyy below the limits on everything here (loaded dyno test).

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Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

[This message has been edited by Ray87Z (edited July 08, 2001).]

 

What if my spark plugs gapping was off...I gapped them at 35 and I heard after that 35 is the gapping for the H.O. engine...would the gap make me fail because of misfiring or should I not even trip about that....Oh and I did put my stock air filter back on...and I have a high flowing cat but says its 50 state legal...thanks for all the help.

------------------
1986 Pontiac TA 305 carb.
K&N Open Air Cleaner
B&M MegaShifter

Future Mods:
3.73 gears
Nos
TransGo Shift kit
Edelbrock Perf. Carb.
Edelbrock RPM manifold

Cool car for being my first and spending $1000 at an impound auction. Had to start it with a screw driver for a bit but it's all gravy.

 

Ok here is what you , do buy about 25 bottles of Dry Gas . and put all 25 bottles in your car , the alcohol will burn much cleaner and drop your co2 , im telling ya it wont hurt , but i would definatly try the dry gas

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Pino
91'Formula
LB9 305 TPI 5-speed
WS6 17" wheels
Eibach Pro-Kit Springs
Hotchkiss STB
SLP exhuast
SLP Cold Air Induction
CatCo Hi Flo Cats
http://www.oldsrocket.com\91bird
and the for ever returning CODE 32

 

Plant protection, read my previous message- since you have high HC and high CO (not CO2)... I'd bet you're running rich. Plug gap would certainly affect that. And as I said, one misfiring cylinder throws emissions way off; your tuneup could've solved a misfire.

Oh and an aftermarket cat-back wouldn't change emissions... unless you had a few holes in it


------------------
-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

ok another question for the post....I had my carb rebuilt a couple months ago and just slapped it on my engine....my question is do I have to program the tps sensor?...If so how much does it cost and where would I go to do it?....the idle is a little off...may be the plug gap but I just wanna be sure...thanks for the help.

------------------
1986 Pontiac TA 305 carb.
K&N Open Air Cleaner
B&M MegaShifter

Future Mods:
3.73 gears
Nos
TransGo Shift kit
Edelbrock Perf. Carb.
Edelbrock RPM manifold

Cool car for being my first and spending $1000 at an impound auction. Had to start it with a screw driver for a bit but it's all gravy.