boosted280zx

So i took my car to get smogged yesterday and as i thought it would, it failed.

The car: 82 280zx Turbo, 135312 miles, all factory.

The Numbers:
15MPH
HC(PPM)
Max - 97
Ave - 54
Meas - 141

Co(%)
Max - 0.98
Ave - 0.23
Meas - 0.97

NOx(PPM)
Max - 1136
Ave - 478
Meas - 2080

25MPH
HC(PPM)
Max - 77
Ave - 40
Meas - 121

Co(%)
Max - 0.78
Ave - 0.16
Meas - 0.65

NOx(PPM)
Max - 966
Ave - 396
Meas - 1379

So i failed on HC and NOx, and made it by a hair with Co.
So I'm running rich for sure, but i'm lost on the high NOx
So i sat for a bit and thought, tested my EGR, works fine, thought maybe the ERG solenoid was bad tested it and i came up with 45.7OHMS, so were good there. So i got to thinking and i hooked up my boost gauge to my EGR vac line, and went and took a test drive. Crusing at
15mph/0inHG.
25mph/0inHG.
45mph/0inHG.
55mph/0inHG

Nothing, not even a flicker of the needle. Car was at op temp, i tried partial throttle, full throttle, closed throttle, everything. i couldn't find a drive cycle in my manual.(I've got a factory manual) So i though maybe i wasn't running it correctly.

So for now I've got EGR as a possibility?

Thought maybe low fuel pressure but that wouldn't explain my high HC and Co. Only my NOx, and the other way around for high fuel pressure.

Thought maybe a bad cat or bad placement of the cat cause it's so far back. that would explain the high NOx.

Thought maybe spark plugs so I pulled them out and there all good, did a OHM check on the wires, good.

That's what I've gathered so far.

Any help would be awesome and greatly appreciated.

EDIT: could me putting 91 in it give me these readings, it kinda makes sense to me, but as the purpose of this is to get a second opinion
(or does it run on 85, i've heard mixed things)

Lupe

Have You Checked Your Vacuum Switch It Could be Failing And Might Be The Reason Your Nor Getting Anything At EGR.

boosted280zx

is that the VCM under the AFM?

Lupe

No It Looks Like This It Should Just Follow The vacuum Line If The Switch Is Clogged Or Isnt Getting Coolant Then It Wont Open...
http://www.autozone.com/autozone/par...=68704_2940_0_

boosted280zx

where is that?

Lupe

This Is How It Looks On My Z But Yours Might Look A Little Different But Should Give You An Idea Of How It Looks

boosted280zx

Mine's a turbo'd ECCS, i believe yours is EFI, and non turbo. lol. i spent forever looking for that today.

boosted280zx

So here's an update:

OHM checked the CHTS( Cylinder Head Temperature Sensor) At the sensor i get 2.3Ohms when car is cooled, after it's been running for a min or two, i checked it again and got .758, so i know the sensor is working.

Checked it at the ECU (BY THE WAY I HAVE A E.C.C.S. NOT E.F.I.) pin 23 to body ground, nothing. So i sat for a min and thought, checked for continuity between pin 23 and the sensor connector, continuity is there, same as the other wire on pin 26, and the sensor connector.

Could it be a short on one of the wires, i would guess pin 23 because 26 is tied into the AFM

Lupe

Oh Yeah I Forgot Yours Was Turbo When I Took The Pic Ill Go And Take A Pic Of My Turbo One Later Sorry

lifegrddude

If you don't have any running issues, I would recommend replacing the catalytic converter if it's the OE one from when the vehicle was new.

FWIW, with my EGR non functional during a pretest, my Z still blew clean enough that it was well under the average levels of cars tested. The VCM should be the thing that controls your EGR valve. The EGR should work unless the tube leading to the valve is clogged from carbon buildup.

boosted280zx

The egr wont turn on if all the presets for the vcm are not good, so if my cylinder head temperature sensor isn't working or getting the ohms it needs to the comp the it wont turn egr on because egr lowers cylinder temperatures. so if the CHTS was not sending a signal to the computer it would default at whatever the specs are set at on the computer.

FricFrac

How does mixing hot exhaust gases into your intake cool cylinder temperatures? Or does the ECU run it richer? If that's the case wouldn't running rich cause problems with emmisions? I'm confused....