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EA81T Failed Smog: High HC @ Idle...

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The smog tech was clueless when i asked what it could be. But it didnt fail by much. It passed everything at idle except for HG, and passed everything at 2500rpm (even passed HG at 2500rpm).

 

I know we have a few smog techs and smog savy members, I'm hoping its something simple.

 

Here are the results:

TEST----RPM----HC (MAX)---HC (Measured)---CO (MAX)---CO (Measured)

Idle:-----981-------120--------136(failed)-------1.00---------0.22

2500rpm------------150--------55---------------1.20---------0.29

 

 

The car has been sitting for a while. Im trying to get it to pass so I can buy it from the previous owners (who are absolutly NO Help at all).

 

-Brian

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I assume HC is hydrocarbons? If so, it could be something as simple as dirty injectors. Does it idle smoothly?

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It DID idle smooth at 900rpm. Then after the smog tech parked it, and I got in it to drive away... i noticed the idle wouldnt go above 650rpm and it had a stumble in it. Like it was miss-firing on one cylinder or something.

 

-Brian

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Im thinking since its only 16 over, it wont take much at all to get it to pass.

 

Im going to let it sit with the current owners for a week, then call them and if its still available i will offer like $200 for the car (they want $650 currently). WHen its in my possession i'll tune it up.

 

-Brian

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got yer PM

 

yeah. HC is basicaly an indicator of unburned fuel.

 

the CO is what tells how the mixture is and it looks really good.

 

HC can becaused by the dirty oil.... maby.

ignition tune up... more likely.

or another one that would be a bit more serious is low compression on a cyl. or two. I have seen this real recently on a corolla. car seemed to run real well with fresh oil, tuned up, NEW cat. it barely passed due to low compression on cyl 2 and 3.

A new cat may help it thru the test but may not really fix it.

 

good idea to let the owner keep the car fo now. its his/her job to get it to pass before selling. you know that one now.

 

the car may have run differently if they messed with timing?

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Some suggestions - check ignition system, advance timing further, run some cleaner through the injectors.

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Well your not too far off. I would have the owner change the oil, poor some new gas in and change out the PCV. They are never going to sell it unless it will pass smog anyway. Your HC are nothing to what my 78 Brat was. HC=3710! :eek:

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The owner wont touch the car. Thats why I had to take it for its smog test, he didnt want to.

 

Im going to go back and do a compression test on the engine. If it passes all 4 cyl, i will give him $250 for it (maybe lie and say its leaking in cyl3 and offer him $100)

 

This car is in an apt complex in the projects. The couple who own it... well... they're crackheads. I cant let the car stay there or it will be towed, i think i'll go back saturday and get it. If it doesnt pass... I'll leave it in their name and park it somewhere :lol: (just kidding of course)

 

-Brian

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If its ALMOST Passing think the trick of running that tankful of "guaranteed to pass" fluid would do it? May be the simple way to get it smogged til you can tune it up in a few weeks...

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3 guys at work told me (after i told them this story) that they used that can of "Guaranteed to pass" stuff, and it all worked for them.

 

I could use that, but the car needs a tune-up real bad from sitting so long, so I think that will be the route I will take.

 

-Brian

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yeah HC is unburned fuel. High HC + High CO would indicate a rich mixture, high HC w/ normal or low CO would indicate a lean mixture. High 02 would confirm this. You could have a plug that's not quite firing at low RPM, or something to that effect that's causing it to misfire at idle, maybe not enough to detect but enough for it to not pass smog. We just covered emissions in class, our AllData software doesn't even HAVE the data for California, it says that since it changes so often it's best to call CARB lol

 

Try different plugs, maybe wires and cap/rotor, and run a bottle of SeaFoam down the intake, might help.

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3 guys at work told me (after i told them this story) that they used that can of "Guaranteed to pass" stuff, and it all worked for them.

 

I could use that, but the car needs a tune-up real bad from sitting so long, so I think that will be the route I will take.

 

-Brian

 

What's the real name of that "Guaranteed to pass" stuff? I need it for two of my cars.

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So can the charcoal canister be cleaned? Does it ever need to?

I failed mine too, high HC and CO at idle.

HC was 252 and normal was 220

CO was 2.93 and normal is 1.2

 

HC could mean vacuum leaks, lean mixture, valve adjustments maybe...

CO means too much fuel, O2 sensor maybe...

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Well I just failed emissions yesterday again for high (700) HC at idle and low CO. Seems like my carb needs rebuilt, had it checked by an emissions guy and he says i'm not getting enough fuel in there somehow, its running lean either way I turn the mixture screw. Not sure if he's right or wat but he showed me on his emissions computer, he turned the screw from all the way left to all the way right and the HC's were really high either way.

And NOTHING works man, i tried a couple bottles of HEET plus denatured alcohol and that "Guaranteed to Pass" crap AND Seafoam and nothing helped, still failed emissions. He also squeezed the PCV hose and the HC's went down pretty low so I'm not sure wats up with that... And he says i have a miss but says that probably not whats causing the HC's. Hmmm.

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Hey Brian,

 

Just my $.02.. but, when the brat failed emission w/ high HC it was the timing.. It was too far advanced... like 14 degrees instead of 8.. First thing you should do is check/set the timing properly!!! It might not be a bad idea to do the spark plugs and plug wires too.. Good luck bro.

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I think SuBrat84 has the right idea about the timing. It's not unusual in our older subes for the vacuum advance unit to fail. Aside from causing a vacuum leak that's not easily detected, it often causes the timing to be advanced (by a mechanic who's tuning by ear) at idle so the car will run better at cruise (didn't you say it failed at idle but was okay at cruise?). Check the vacuum advance to see if it's working; use a timing light to set your advance to 8 degrees BTDC with the vacuum line to the distributor disconnected and blocked; then re-connect the vac line and see that the timing advances about another 20 degrees as you rev the engine to about 2000 rpm.

Hey Brian,

 

Just my $.02.. but, when the brat failed emission w/ high HC it was the timing.. It was too far advanced... like 14 degrees instead of 8.. First thing you should do is check/set the timing properly!!! It might not be a bad idea to do the spark plugs and plug wires too.. Good luck bro.

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I would change the oil and maybe put some 40W in it to slow the intake seal leakage/ ring blow-by; and dump a couple cans of B12 in the tank when it's about empty. Then run some fresh gas through it and test again. Good luck!

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