CO to high for smog check

[john]

Hello All,

Failed the dreaded Calif. smog check again. I joined the group a couple years ago when this happened and received tons of help and got mt '85 tercel 3AC through the check after replacing the AAP valve.

This time my readings are very low for HC and very high for CO.

At idle my CO measures 0.00 and at 2500rpm it jumps to 2.82; max allowed is 1.20

The AAP valve I installed 2 years ago was from the junkyard. I took it out and checked it this morning and it still seems fine. I held it up to the sun and could not see any holes.

As I understand it, High CO indicates a too rich mixture.

Any ideas will be appreciated.

john

[tercel4wdrules]

Did it fail an official smog check or was this a pre-test? If it was an official smog, I would advise to always do a pre-test, but yet even better would be a manual mode test.

Perhaps this time the carb might have an internal problem presuming the AAP is still good, unless the TVSV is bad and is allowing the AAP to get vacuum all the time. You can verify the operation of the TVSV rather easily. How old is the O2 sensor? This website has good info: http://www.recarbco.com/index.php/smog/ ... -hc-normal

[john]

Hello TercelRules, I was hoping you would check in. It was an official test. Once again i am a gross polluter. I really felt like I would pass no problem. Car runs very smooth, plugs are golden brown, low miles since 2 years ago. Looking now at test results from 2 years ago, Co was borderline pass back then.

Have any of you bought a carb from National Carbureators? Yes, I probably spelled carb wrong. National offers a carb for $149 an $20 core. Too good to be true? Autozone is $400 or $500.

I will test TVSV . Oxy sensor is original.
Thank you for info. john

[ARCHINSTL]

I bought one from National back in 2005 and was happy with it. I forget the price, but it was more than $149. It had a lifetime warranty, which I exercised in 2007 when the AAP stopped working - and there was also some kind of grit in the ___.
Tom M.

[marlinh]

I think the aap valve has to be pliable as well. If the rubber is stiff it won't work properly.

[Petros]

the carb is not diffcult to rebuild, kits are only $30 to 40. but before you tear into the carb you need to diagnose it BEFORE you try and fix it. it may or may not be the carb. There is a trouble shooting guide in the FSM, you just have to go down the list.

Chances are it is not the carb but one of the external components. If you eliminate everything else than the carb would be the last thing I replace/rebuild. If it is not running badly than I would suspect the carb is operating properly.

If it is the APP you can just disable it, it not necessary to run properly, it only helps driveablity when it is cold and the choke is still engaged.

good luck.

[john]

I do appreciate the tips. The AAP valve, which came from a donor engine is not pliable and probably original equipment. I will buy a carb kit and just replace the AAP. I never had much luck rebuilding carbs so will just do the AAP. The TVSV valve failed all steps in the blow test. I will now look for a new one. Dealer only I presume?

[dlb]

new TVSV's are only available from toyota at this point, AFAIK. about $120 a pop! there were some to be had from asia for a while but i recently checked those sources and they have dried up, unfortunately.

[irowiki]

Junkyards are still a good source. Most 1981-1987? Toyotas may work.

[john]

Current Price at our local dealers...drum roll please...$169.78 for TVSV

[Petros]

look for TVSV at wrecking yards, most of the carbed toyotas (all models) from 1980 to '88 had them. get a handfull of them and test them all, toss the bad ones.

The aap can be disabled by capping off both sides of the vac line, on the carb side and the TVSV side. it will run fine without it, just stumble a bit on hard acceleration when stone cold (which was normal for all cars and trucks when stone cold since the beginning of time). Having it disabled will not alter the emissions test outcome, or normal drivability.

[dlb]

i have yet to find a junk yard TVSV that passed the FSM test. not to say there aren't some out there but i think they are few and far between.

[irowiki]

The one I got for my 81 out of an 82 (brass) seems to work but I haven't tested it.

[john]

I went and ordered the valve. The closest one in a junkyard is 50 miles north of here, and no promise it still has a TVSV. The price is about double the price of the last complete engine I bought. It is still cheaper than a car payment and I do love my tercel. I asked the Toyota parts guy if this TV valve included Netflix at this price... It took a moment but he started laughing as I hung up.

[Petros]

I wonder if some similar valves be adapted to work in our cars, there are cheaper valves available for other cars. It might be possible to get it work by using the correct "T" and "Y" to get it function properly.

for exmple, this is a Delco valve I found on ebay for about $35


http://www.ebay.com/itm/NOS-Delco-Therm ... df&vxp=mtr

and this one from SMP for about $51


http://www.ebay.com/itm/SMP-STANDARD-PV ... 39&vxp=mtr