Failed smog again, only the 15mph test, something broken?

Well, failed again


however, I have noticed a trend, the only part of the test I fail is the 15mph test, and only the HC and CO part(the january test has the same pattern). Another thing that worries me slightly, is that all of the numbers have risen(compared to the january test). Full tank of 87 with seafoam, new oil, and even drove it hard before testing.

I asked the smog tech/mechanic his opinion, he suggested maybe the air pump. However, he recommended a full diagnostic before any further action be taken. I'm at the end of my rope, so i'll probably take the shop up on it (its a star smog shop). I just don't have time to figure it out.

Any ideas why only at the 15mph i fail? Is their a system that should be doing its job at that mph that just isn't working?

15mph: HC 530(max 134) CO 4.04 (max 0.58) NO 26 (max 847)
25mph HC 57 (max 76) CO 0.34 (max 0.49) NO 26 (max 786)

interesting, my 25 mph NO numbers went way down compared to January.

Your running rich and not getting full combustion.

Maybe drop a idle jet? (I think that's the one I'm thinking.) or increase the pilot.


Also advance your timing a bit

"Full tank of 87 with seafoam" < This could be your problem. Never put anything in your gas tank except gas. Preferably 91 octane. Timing should be at 5*.

And air pump? I've never seen an air pump an a 4ac. The tech make have been smoking the sticky icky. Either way, I wouldn't listen to a smog tech. They're not exactly professionals.

found something interesting in my engine bay, the retard and advance hoses for the dizzy where both disconnected. However, i don't think it will make a difference. Oh well, car goes into a repair shop either this friday or monday. I shot myself in the foot with this test, lets just hope they figure it out. The car was to drive on the way their and back.

the timing is set at 5 BTDC. i connected the hoses, and it went up to 10 btdc. slight driving improvement too. cool.

also, at 15mph, the Co2 is 12.0% and the o2 is 0.4%. at 25mph, the co2 is % 14.1 percent, and the o2 is 0.6%

so, its running rich at 15, but ok at 25? is their something that controls this on the car?

Well there ya go. Disconnected vacuum lines won't get through smog.

Friday is my next free day. I'll get another day pass, g for any even longer drive, and ask for a quick pretest, I just feel that isnt the root of the problem. It'll bring down the numbers, but i doubt it'll pass

Try pulling your ail filter out. Might lean it out enough to get through.

hmm, spark plugs gaps are way off. they measured at .035, there supposed to be at .044 unfortunately, my gap gauge only does .040 or .045. The air 'injection' (it is the box looking thing on the stock air cleaner, has one small vacuum hose and one big hose going to the exhaust manifold) is working.

So, i took it to a shop. They gave up, they can't figure out why it dumps gas at low speeds. it just does. Fuck me

I'm having a similar issue I'm failing at idle with 250HCppm and about .75% on the CO. My problem is because the idle mixture is to rich on my car. So drill out the plug for the idle screw and adjust it if needed and maybe like the other guy said pull the air filter out.