ok, so im a gross polluter now.... my co2 readings were off the chart, my nox was pretty high, well....they were all high, so far, i have replaced the o2 sensor, all vacumm hoses, all fuel line hoses, and flushed the radiator, with new coolant, my next part to add is a new thermotime sensor...? good move? or stupid move? a key element is when i replaced the o2 sensor, it had grey ash on it, meaning its running thin, what sensors could go bad that would make it run thin?? oh, i have a 280zx turbo 82...if that helps any, any help on this one would be much appreciated, as i currently have a fix it ticket for my registration, and i cant get registered without smog...

 

Well bud, I just went through this nightmare a short time ago. I know pretty sure that NOX is your EGR valve. It could be plugged up, and not functioning correctly. Also for the Co2 readings, you could be running rich, and or your cat could be plugged or bad. Even though I passed with a gutted cat. But I would also check your AFM. It could be faulty, and sending a wrong signal to the ECU. Also maybe your air filter, that could cause richness problems.

I will be honest, I do not know much about Turbos. So don't take this info as gospel. I just figured I would tell you the small things to check out. I am sure a Turbo expert, can help you out more than I can. I know how to dial my n/a for emissions. I don't know if it will work on the turbo. Anyway that is all I can help you with. Good luck to you bro'

 

Gabriel, how far over were you?

Do what Wildman said. Also turn down your timing (you can turn it back up after).

 

This may be a long shot, but many people are raving about it. It may be worth it to try to get your emisions down.
http://www.4ecorp.ws/number1priority/index.php

 

Yeah... my neighbor swears by that stuff. I had him put a lil in my Saturn's fuel tank.... I didn't see any diff. Prolly gummed up the combustion chamber

I love this:

Supposedly it works better with Diesel.

 

Check to see whether someone blocked up the hose that goes to the fuel pressure regulator because I have seen plenty that were purposely blocked by some chucklehead.

 

Thermotime wont affect emissions unless you have it tested while the engine is still warming up (not highly intelligent). How old is your cat? And was it your CO that was off the chart, or did you mean to put CO2? If you're running lean then it's probably your AFM. Not much else would cause a lean condition other than actual fuel starvation. Rich is another story. Which state are you in?

 

sorry for not responding in a while, ive been through hell this weekend, well, i know for sure it isnt the afm because i just installed a brand new one not too long ago, i replaced all fuel hoses and vacumm hoses so shouldnt be clogged up unless clogged in the fuel rail, on thing it must be is the cat, because i recently just cleaned out the entire cat, and i just had a dyagnostics done and it read that the cat is bad...the guy at the shop said just replace the cat and it will pass emissions...so now that i know it is the cat, what type of cat would be best to go with for emissions and also for performance?? and what type? 2-way, 3way?

 

you can get a high flow 3 way for bout 100 bucks, make it removable so it doesnt ever ware out, thats what i do, that and you can run a couple of liters to a full tank of methyl hydrate, its good stuff, boost the alchol levels in the tank and burns super clean. on a na application you can also unplug #5 injector to make an onboard air pump, the car will still run fine, just dont let them open the hood, or make it so there is a break in the wire. i dont know if that will work with turbo or not tho.

 

ill go with the high flow 3 way, just have to wait till next pay check....yay!

 

Also, remove and clean every connector to every sensor with electrical contact cleaner and then seal it with di-electric grease. The grease will keep air and moisture away from the connection so it won't corrode as easily.

Use the electrical contact cleaner on your ECU connector as well.

Even though your AFM is new, the connector to the wire that goes to your ECU is probably the same old one unless you replaced your electrical harness as well.

It's very possible that your old connector has some corrosion built up on it. It'll look tarnished and may have a green hue to it.

Most of the reliability problems on these cars can be remedied by following the procedure above. Once that's all done, then you can start replacing parts, although I'd recommend getting a voltage meter and a Factory Service Manual, so you can test them before you replace them...

Good luck.

 

And a new AFM usually requires some calibration after installation.

 

Another good point J.

 

Don't worry about it. Just find a crocked smog tech and have him smog your car.

My car can't pass a smog test to save it's live. I'm a 98 obd2 car running a 93 harness, ecu and engine, which is obd1. Plus with the tt swap, and the fact I'm running without precats into a straight exhaust with no cat. Then you throw in everything else and I can't even open my hood. But it doesn't matter, my friend takes care of it. So don't worry about it, when there are 100's of these smog techs running around

 

A LOT easier said than done. I worked at Nissan for 2 years & got to know a lot of techs at that shop & around town. No one wants to just "hook you up" even if you slide them some $.... they're job is on the line when they do it, so ya gotta be bud's w/ them.

 

yeah just cause a tech is willing to hook up one person doesn't mean he's going to do it for someone else. I've been reffered to someones "buddy" before only to be looked at like they didn't know what I was talking about. Getting around a visual inspection is the only part of an emissions test I've ever been "hooked up" with from a friend that knows a friend. But as far as actual emissions output goes, I've yet to meet anybody willing to falsify that part of the test. Of course thats CA.

 

i really dont mind making it a smog free car, its good for the environment and all that crap, plus the better your emissions do the better you gas mileage is, all bad smog is, is gas that hasnt fully burned off making hydrocarbons, the less hydrocarbons, the more gas that is burning more efficiently.

 

Easier said than done because you go to jail if you're a smog tech. who passes a car that shouldn't.

 

thanks for the info lww, im going to take that into deep consideration, because i know when the afm was put in, (i had a shop do it) i have a strong feeling they didnt clean the contacts to the ecu, and i still havent done that since ive owned the car, im gonna give that a go tonight after work, see what the contacts look like. plus i now have a factory service catalog with full diagnostics they i can work on. thanks for the advice, much appreciated

 

Crap..............I just remembered the wiring harness connectors that plug into the ecu have huge problems on the zx turbos.

I actually cannot remember a 280zx turbo that didn't have this issue.

 

Zactly! Corrosion up the ace!

 

Thats funny cause my ZX turbo was covered in rust. Floorboards rusted right through. All the electrical connectors were corroded badly. Ground wires were corroded feet into the insulation. All EXCEPT the connector for the ECU. It looks brand new and I haven't had to clean it up at all. It's just funny to me that my car was in such bad shape corrosion wise except for that part.

 

Yep......doesn't need corrosion to be a bad connection.

I was taking the harness from the latest z31 I could find and repopulating the connector in the proper places to match the 280zx pin out such that I ended up with the contacts being 8 years newer than my 1981 zx turbo.

Sadly.........I find the boards cracked on many of these ecus and no amount of connector tom foolery will fix that until the cracked traces on the board are jumpered or reflowed.

 

so will the ECU connectors from the Z31 plug directly into the 83-83 turbo ECU's? I'm not neccessarily talking about pins being in all the same order but more so that the actual plastic of the connectors will plug right up to the older ECU's.

 

Yeppers! I found that out just the other day when I started my Z31 ecu swap.