failed smog

[rrpjr]

84, Euro, low mileage. I rarely drive it. Same half tank of gas in car for the past 2 months. I worked it out this morning, took it in for test, failed. Results attached. Technician says I was close enough to suggest just driving it a lot more in next few days, emptying tank, filling with new gas and Techron should make the difference. Sound about right? Thanks.

[rusnak]

I usually turn to BG 44K on smog test runs. My ritual is to run a tank of BG in the car the week or two before, then when that tank is gone, refill a second tank with BG, then take it in for the test after getting the engine really hot.

The last time, it wasn't hot enough outside to get the cat very hot, and the car sat around before the tech could test it. I thought for sure it was going to fail, but it BARELY passed. After making me do the test only smog 4 times in a row, Calilf DMV are finally giving me a break, and letting me do a normal smog test.

Yours is so close, I'd suspect either the cat is too cool or maybe some BG might help. I tried Seafoam too, but it smokes so much, you'd definitely not want any in your gas when you try to get it smogged. It's curious that yours would fail on the low speed run, and pass on the high speed run. My theory is that the cat heated up, and that's what cleaned up the numbers.

What do you mean by Euro? Converted to us smog legal? What equipment is on there now?

[Mr.Puff]

Huh, my '84 passes no problem. I just drive 15 minutes and go . It doesn't have any upgrades though.

--Puff

[Steve W]

High HC and CO, where NOx is low, means the mixture is rich. Your problem is at low rpms around 1400-1500, so you can lean it out at the idle mixture screw under the air flow meter. Turn it out counterclockwise several turns should be enough to get you under the limit. You can also in addition use the fuel quality switch to lean the mixture further. The car will run like a dog, but you can set it back later.

[Peter Zimmermann]

I'd advise to have a pro check/set the CO%. There are times that simply leaning out the mixture will increase HC, which is already too high. Your car might have an intake manifold leak, incorrect spark plugs, etc., so you should probably have it checked in order to avoid a tail-chasing exercise... That said, bringing the CO into spec might be all that's necessary.

[rrpjr]

Thanks for the advice, gentlemen.

Rusnak: I don't know what BG is but I imagine it's available at any auto store?
The car is RoS import, with standard smog equipment updates.

[rusnak]

BG 44k is like the "Magic Dust" that Santa used to make his sleigh fly in the old Cheech and Chong tapes. This stuff is great.
http://www.bgprod.com/products/fuelair.html


I think Pete's analysis makes a whole lot of sense. Checking for vacuum leaks is easy enough with a can of starting fluid. Also, make sure you aren't just using old gas. A fresh tank of premium is absolutely necessary.