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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Hi all, recently moved to the (not so) beautiful lands of CARB testing and failed my first emissions test with my 1989 RS, 305 TBI Manual Car (single cat). The catalytic converter on the car is easily 30 years old, so I'm not surprised, I'm wondering what users here suggest replacing (besides a new cat). I did have to argue to the tech that this car only came with a single cat, as all 5.0L Camaros on his database from 1989 came with 2. I'd assume that's a Federal vs California emissions certification difference. Though I'm unsure as I've found CARB databases that suggest some 1989 Firebird in CA came with a 5.0L and a single cat, so who knows...
I did a DIY rebuild of the engine a couple of years ago (rings on one cylinder had snapped in half, despite only having ~75K miles in 33 years), replaced rings, power-drill "honed", nothing fancy, but all seals were replaced. In doing so I also replaced the O2 sensor, cleaned and re-sealed the TBI, replaced the engine temp sensor, and new EGR valve. (amongst other things, but I think that's most relevant).
Unfortunately for the first time in my life, I'm living at an apartment with nowhere to even jack the car off the ground, so my options outside of taking it to a shop are limited. From what I've read I was planning on replacing the air filter, performing an oil change (might have to have that done for me for the first time in my life...), and potentially replacing the O2 sensor again? I'm curious if other points in the EGR system are common failures I should look at such as the electric solenoid? (I unfortunately don't have the means of testing it on me...)
I've also attached the condition of the spark plugs I pulled when replacing them before my 1000mi trip to CA. I've noticed every time I've pulled a plug on this engine since I've owned it that there is a white-brown coating on it. Not sure if this is due to the gasoline additives where I used to live or is an indication of a lean condition, anyone's input would be appreciated.
Each re-test is $100 or so, so as much as I hate throwing the parts cannon at problems, I'm not sure where else to go. Advice on where to focus my efforts would be appreciated
You didn't fail that bad actually. I assume you gave it a good tune up and changed the oil recently.
For the HC, what is your timing set at? I'm not as familiar with the TBI cars, but I know that the TPI cars are supposed to be at 6 degrees. For smog checks, I retard mine to 4 on the morning of the test and put it back after the test. That should bring your HC down. I seem to fail for NOx about every other test. To pass, I replace my EGR valve and clean out the passages while I'm at it. That normally does it.
As far as the dual cats, look at your RPOs. If you don't have N10 then you don't have dual cats. I may be wrong, but I always thought the dual cats was only available on the TPI cars.
Just get it a new cat. I don't see anything else wrong. Speeeeeeeking strictly as someone that lived in an "enhanced" emissions testing zone for some years.
TBIs don't have dual cats. Ignore all that. Your deeeeeeel is pretty basic.
I will add..."I know a guy" who does the following before visiting the Cali SMOG ****'s.
Inflate rear (drive) tires to about 50 PSI,
retards timing 2* (or whatever variation cali allows , these days) and
adds (about a quart or more) alcohol, to the fuel tank, that has about 5 gallons of gasoline in it. Denatured alcohol is first choice, but you can not buy it in cali. (or Nevada) Second choice would be "Heet" brand fuel line additive. Third choice, Isopropyl (Rubbing) alcohol.(if you can still get that. Buy the isopropyl with the lowest water content.
RIGHT after SMOG test, adjust tire PSI and add gasoline to the tank.
Can't buy denatured alcohol in California??
Why is that?...
That is difficult for me to answer, without getting political and annoyed (at cali).
Ca. "VOC" Volatile Organic Compounds are highly regulated because , I guess. ca legislators and CARB (Ca. Air Resources Board) believe anything that evaporates fast, causes pollution.
Ca outlawed "Winter Mix" (resists freezing to about 0* F) windshield washer fluid, decades ago. A big F-U to cali vehicles owners who live or travel to areas that drop below 32* F , in winter. I presume CARB thinks the slight percentage of alcohol in winter windshield washer fluid, will destroy the planet, when one squirts a few ounces on their frosty windshield!
I could go on and on and cali's ridiculous laws. But I will not.
Supreme Court Of The United States (SCOTUS) recently ruled that government agencies, like CARB, EPA, ATF, etc. "Rules" are unconstitutional. Something I have said, for decades.
I've never had to do emission testing but things that I've heard that may help.
Retard timing 2*
Put about a cup of methyl hydrate into a full tank of fuel
Change your spark plugs and air filter.
Install a 195* thermostat and take the car in for testing when the engine is hot.
The downside is that lowering one emission will usually increase another.
HC is generally misfire related. Plug, cap, wires, rotor and any ignition issues needing attention can help. So can alcohol and slight retard of advance. A not-fully functional EGR can allow hotter combustion which in my experience, can contribute. I have never had to replace a cat for a mild HC failure on a SBC car.
That's really interesting his work info listed dual cats. I was researching other SBC TBI stuff, hoping to find a certified combo with 2 cats and TBI. None that I know of for the U.S. market.
07-21-2024, 08:57 PM
Looks like Champion made those plugs for AC Delco... 
