Hey y'all. So, I'm trying to get my car licensed in Arizona and she's not passing emissions so well. I just recently went through this in Missouri. Last time both Hydrocarbons and CO were twice that of the acceptable maximum. I adjusted the mixture via the MAF way down until it almost wouldn't run, then turned it back some. This worked that time but I tried this time around thinking that it had just gone out of adjustment and it actually got worse. I went out and bought some NGK plugs, wires, an EGR valve, new distributor rotor and cap, and changed the oil. I'm going in tomorrow again to see if these things helped. I'm about to mess with the MAF and get it as lean as possible again, but if anyone else has any ideas, please let me know!!!

 

I also checked the timing and it appears to be way off. What should the timing be set at for the l24et??

 

12 BTDC

Replace that oxygen sensor! If that sensor was bad and you replace it, because of your AFM adjustments you may be running way too lean. Replace the sensor and then adjust the AFM slightly more rich untill it runs good.

 

O2 sensor will be the next to go if it doesn't pass today after I get out of work. My timing is currently more advanced than 12 btdc.

 

anywhere from 10-15 deg works fine for the L-series engines. 15 for 4-cyl 10-12 for the six. That shouldn't effect your emissions much. The oxygen sensor and fuel pressure do affect it more. If you still fail, test your fuel pressure. If you can't, then maybe find a used fuel pressure regulator from a 280Z or 280ZX and stick that on there. Maybe your pressure was too high. Mine was once.

 

Funny how you guys use 10-15 deg timing. The 2nd gen is up around 20-24 deg timing.

S

 

With or without the vaccume advance? The L-series is to be set at 10-15 with a timing light with the vaccume line unplugged.

 

Oh, I didn't realize that you had to unplug the vacuum advance to do the timing (whoops). That should change things a bit. I still need to go get a new O2 sensor. I'm probably going to go get one of the Bosch universal units later today. It seems like those are recommended.

Also, just to clear this up, there are a couple of what look like vacuum ports on the top of the rearward part of the intake manifold that don't have anything attached to them. I can't find an accurate vacuum map, but one looks to be a check valve (or something) and the other is just a straight flange. Are these small ports supposed to be hooked up to anything? As far as I can tell, there is nothing for them to connect to. I can get a picture of this uploaded shortly.

 

Were are you having trouble passing the test? Idle or running?

And can you post the actual #s of "failure"?

 

Im going to have mine tested too on a sec. gen. I use your points and hopefully ill pass too

 

So I checked the compression all around and all six were at 155-160psi. I replaced the O2 sensor, leaned it out even more and advanced the timing more still and it finally passed with flying colors. My timing now appears to be roughly 20 btdc without the vacuum advance. I swear that what fixed it was all due to proper adjustment of the AFM. In anycase I can finally register my car in AZ now. Thanks for the help y'all!

 

15 mph hc max = 138. mine = 316 gross polluter = 328
25 mph hc max = 110. mine = 358 gross polluter = 261

15 mph co max = .98. mine = 8.12 gross polluter = 2.48
25 mph co max = .78. mine = 8.89 gross polluter = 2.28

functional check = fai. was pass or N/A on all things except the fuel cap.

here are my test results for my 82. the car has sat for around a year or so, and i changed the battery, spark plugs/wires, dist. cap and rotor, and threw in some stuff in the oil that is supposed to clean some stuff, and also some injector cleaner in the gas tank. The car is past registration, so i cant really drive it around that much. (so the injector cleaner never got to work, and there is still a good amount of the old gas still in there). So im thinking that if i drive it around more, get the old gas out of it, and replace the o2 sensor it should pass (or at least come close to it?) And on the first test some liquid came out of the muffler, looked like water, but there was a black film over parts of it.

 

just noticed timing has to be 4 btdc (failed)

 

wheres the screw to adjust the maf to lean it out?