greetings all.

am a proud owner of an '87 max. just recently failed ca smog. wouldn't hold an idle and emissions were over about 400% of what they should be. any suggestions on an inexpensive way to figure out what the problem is.

any and all suggestions appreciated. by the way have over 230,000 miles and going strong.

 

well use good high octane gas cleaner is better. Make sure that when you go in that the cars temp gauge is at half way ( the correct) temp for diagnosis. Because if the car was cold still not all emissions are being done effeciently to get the best ratings do it when the car is completely warmed up. Any other Suggestion guys? Ive never had a problem with emissions.

 

It depends on what exactly the emissions report says. By interpreting what failed and by how much, you should be able to pin point the problem.

Off hand, I can think of a few things that I would check. They would include the EGR valve, the O2 sensor, and the catalytic converter. I'd also check the computer to make sure there are no bad sensors. The sensors are used primarily to make the car fuel efficient and to keep the emissions low, so one bad sensor could certainly cause you to fail the emissions test.

The computer is underneath the passenger seat. You'll need a Chilton's/Haynes/FSM to interpret the codes, although I believe there's a link to them in the FAQ section. Nevertheless, I'd still recommend picking up one of these books, as they can greatly help you determine what's wrong with your car.

-C-

 

You have to be up to operating temperature to get an accurate reading.
Even a new car can fail if you go through cold. I also hear "oxygenated" fuels help, like an ethanol blended gasoline.
On the EGR, if you can get it off you can clean out the hole with bore brushes like you get in a gun cleaning kit. No idea what size yours would be. I'd guess around a 30 caliber.

 

Nobody has really told you how to warm your car up for your emissions test. You should take it out on the highway, and hit the gas pretty hard and get it up pretty fast (be careful, and don't get pulled over) then slow down a bit, and do it again, then do one more time, for optimum results you should probably drive about 15 minutes, if not more. Goodluck, oh also think about running some engine cleaner and possibly gas tank and line cleaner through your car. Go to an autozone and read some of them and ask how to use them correctly.

 

Because we took his knowledge assuming he knew how to warm up a car as should everyone else, Hopefully

 

Even if his car wasn't warmed up, it still wouldn't have been 400% over the limit. There's obviously a bigger problem here.

Also, the guys doing the emissions testing know that the car has to be warmed up, so usually they'll do the road testing of the vehicle before they do the emissions testing.

-C-

 

I've never heard of that anywhere, the road test thing.

 

Well, maybe it's different for every state, but here in PA they drive the car to test the brakes and sh*t to make sure it's okay. It's part of the inspection test.

-C-

 

Yeah me either. They just drive it into the garage make sure lights work, windshield wipers and blades are ok and work, they check under the hood, do emissions, and check the tint for legality, thats all I know of there could be more but they dont drivem down here.

 

In my county, here in Texas, all they do is visually check the tires and emissions system - no actual emission test - , honk the horn, check the lights (which they no longer even check for proper aiming), and check for exhaust leaks. The drive into the garage is all they use to check the suspension & brakes, although they usually do slam the brakes upon entering the bay. Other than than that, as long as your windshield has enough surface area to hold the inspection sticker, you're good to go...

 

Certain readings on your exhaust emissions will tell if your car is running rich, lean, or possibly has some unburnt fuel. One year my Z failed both idle and revving emission checks. It was way over. I knew something might be up because it seemed that I had a little bit thicker exhaust than normal. It ended up being that my fuel pressure regulator was bad and keeping too high of a fuel pressure all the time. Replacing that fixed the problem. My truck failed one year on just the idle check. That ended up being a bent valve that I must of bent when I had the head in my garage. That one cylinder had very low pressure due to the leak and wouldn't fire at idle. At higher rpm the fast action of the pistons caused a little more pressure and got it to fire a little, which still wasn't good for it. After fixing that I had a lot more power and passed emissions great.
My dad's truck once failed and that ended up being that after he warmed up the truck, he had to set in line for 20 minutes idleing before the check. The next time, he went during the morning when not as many people were in. He drove straight off the freeway into the bay for the testing and passed.

If you think you are running too rich, check things like the fuel pressure, sensors like was said earlier. Also, make sure the car is just running good and has nice smooth torque at low rpm. Do a compression test, replace spark plugs, distributor cap and rotor, ect.

 

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