Wednesday, January 30, 2013

The Old '87

It seems like I do more writing about my '87 Toyota pickup than just about anything else. I certainly spend more time fixing it than the one other car in the household, the '02 Focus. But then the Toy is older and has way more miles on it.

It was smog inspection time this month. Nevada inspects vehicles every year but only in urban areas in two counties - Clark (Greater Las Vegas) and Washoe (Reno). Lucky me, I live in one of those areas. It's not too bad though; generally the inspections are inexpensive and don't take that long, especially for the Focus. You see Nevada does OBD only testing on vehicles from 2000 and up so the Focus took about five minutes. The Toy on the other hand took about 15 minutes because it gets a two-speed "idle" test plus some visual and hands on tests.

The good news was that the Focus passed. The bad news was the Toy did not. It failed the carbon monoxide (CO) at 2,500 rpm by a whisker. If also failed the fuel cap test but what the heck, it was the original cap. It ended up it was all my fault (I'll explain later). The equally bad news was that the Nevada test doesn't show all the readings, just what failed and by how much. So I knew the CO was about .3% high at 2,500 but had no idea what the CO, HC (hydrocarbon), or O2 (oxygen) was at idle or the HC and O2 at 2,500. And I don't have access to the equipment.

So I went on the assumption that it was running too rich and that this was the only problem. For some reason the first thing that came to mind was I would have to take the carburetor apart. It's never been opened up and the air/fuel adjuster is sealed. Thankfully I had to go on a short trip to LA so I could not just tear into it. I say fortunately because I have this habit of not thinking things through and the trip gave me time to ponder the problem and discuss it with someone else (thanks CF).

Dr. Dean Edell used to say that if you hear hoof beats don't assume it's zebras, which is another way of saying check the obvious first. In the case of the Toy I checked what I should have checked before taking it for the inspection. I knew the oil and filter needed changing; I hadn't looked at the plugs for over a year and the air filter was about 3 years old. So I changed the oil and filter, re-gapped the plugs (they were in good shape otherwise except for an indication that the air/fuel mixture was rich) and checked the air filter. At first glance the air filter looked pretty good - the paper was fairly white to the eye. But on closer inspection (the old "hold a light inside and see if the light shines through" test) it was just about plugged solid. Now on a fuel injected, computer controlled engine this is not a death sentence but on a carbureted engine a clogged air filter is like running with the choke closed. So I put in a new filter.

I then took it back for a retest and it passed no problem. I still don't know what all the readings were/are but it passed.

I relearned two things - do the maintenance before you smog it and always - ALWAYS - check the basics first.

One of the good things about the smog station was the price - $14.99 with a free retest. One bad thing though - they are idiots. When the Toy failed the service writer said all it probably needed was a "fuel system conditioning." Uh-huh that would have fixed it just fine.

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