$%^&ing emissions!!

[ddezso]

I am trying desperatly to pass emissions and get my car titled and registered so I can drive it legally. I just brought the Z in to get tuned and the carbs balanced and synched because I knew they were running rich and I didn't want to mess with it.

My mechanic told me the mixture adjustment screws are bottomed out so he can't make it run any leaner and I need at least new nozzles and needles and maybe bushings (a ZTherapy job is in my future).

The state of Arizona offers a 1 year 1 time only waiver if you spend $200 or more on repairs so I went to get a waiver today. What they fail to tell you is if you fail the CO test at idle they will not give a waiver under any circumstances. God I was pissed to drive all that way and find out I need to spend $600 on new carbs at ZTherapy.

Questions

Are there any ways that anyone knows to lower the CO temporarily so I can get a waiver and buy some time to fix the carbs? Any way to make the emissions machine think it isnt running so rich?

[jmortensen]

Find a mechanic who knows SU's.

[Arne]

Sounds like the float levels are too high. The fuel level in the float bowls needs to be lowered.

[mlc240z]

on other cars i've owned with a similar emissions test, i would always remove my air filter before testing. i figured without the restriction of the filter, a little more air couldn't hurt.

i can't say if it made any difference, and it might have passed anyway, but i never failed emissions.

[ddezso]

Good idea. The max reading for CO idle is 5.00 and my reading was 8.30.

Will any tricks move it that much?

[Arne]

Well, you could try dropping the needles in the pistons a touch. That will lean the mixture out some. But the most important and basic adjustment on the SU carbs is the float level. That's what sets the basic mixture, the adjusting screws are just for fine-tuning. I still think that's your basic problem. And I gather you aren't comfortable doing carb adjustments yourself, so if you're going to pay some one to fiddle with things like dropping the needles, better to pay them to set the carbs up properly instead.

[jmortensen]

I think Arne's on the right track. When I got my first Z it had failed emissions. His mechanic had tried to lower the needles and they were really uneven and bent. It was pretty horrible.

I told the guy to knock $200 off the cost and I'd fix it so that it would pass smog. He agreed, and I bought some new needles and nozzles. A friend of mine did a simple tear down and clean and installed the needles and nozzles, thing passed after that.

Also, IME passing smog on a 240 is a tricky business. It has to run on the ragged edge of lean to pass. Once passed, I would richen the carbs up quite a bit and it would run 100 times better.

[ddezso]

I think I'll spend the $150 to get new needles and nozzles from ZTherapy, put those in, pull the air filter, and get retested.....I hope that does it.

[Arne]

Just be sure you check the float level too. If the level is too high, it's still going to be rich, no matter what new parts you put in it.

[ddezso]

Arne - how do you check that? I'm a novice.

[Arne]

Your shop manual (if you have one) will tell you. And ZTherapy's refresh kit includes their video, which also has instructions (I believe).

[montoya_fan01]

Pulling the air filter may work where you are, but it may not. In CA your vehicle must be eqipped with a proper airfilter and any other equipment that came on the car. I recently had a similar experience at a "Test Only" CA Smog Test facility with an '81 Mitsubishi.