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Discussion Starter · #1 ·
In bringing my 76 280 back to life....
Step 1 - get it running...completed sucessfully
Step 2 - get it to not over heat...completed sucessfully
Step 3 - pass smog req....2 pass, 2 fail..as follows:
Loaded Test for HC- standard is 250, reading of 118-pass
Loaded Test for CO- standard is 1.50, reading of 2.49-fail
Idle Test for HC- standard is 250, reading of 468-fail
Idle Test for CO- standard is 2.00, reading of 0.75-pass

The engine revs smoothly with power to 5000...as high as I've gone so far, idles smoothly at 900...100 above the book, plugs are burning clean, no carbon for what little its been run. Engine temp stable at 180 degrees (until I can chase down a 160 tstat). The brake booster does have a vacuum leak when the pedal is pushed...idle speeds up and gets rough...and they did have the brakes applied while testing at idle. ANY SUGGESTIONS???

Those smog folks are thorough too!! underhood check for stock emission equip, mirror to look under the veh...I did have to show them where the pcv was located, they were going to say the z did not have one!
 

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Hey, my son just got his new (to him) 82 280ZX to pass smog here in Phoenix. We had to meticulously clean ALL the underhood sensor connectors and rebend the terminals for a tight fit. Paul (a mechanic at Midway Nissan) told us these cars don't pass emissions because the sensors do not feed back properly and also, ANY vacuum leaks cause the car to lean misfire, thereby flunking the HC portion of the test. Check the oil dipstick seal and the PCV hose to the top of the valve cover also. Hope this helps.
 

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Discussion Starter · #3 ·
Thks Jerry-This is what has been done...

I know the vacuum booster leak is not good...goint to plug the line until I save some $$. The dip stick and pcv connections are tight. The sensors and sensor connectors are new, replaced the bullet connectors, replaced the injectors and injector connectors, cleaned the TPS, cleaned the connectors on the AFM, Air Regulator, cold start valve, adjusted the valves, vacuum lines are new. I'm pretty sure the fail at idle is the booster leak, but am puzzled on what causes the fail of CO under load...?? Anybody on the list have ideas...all suggetions greatly appreciated!
 

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Gary,
sometimes folks get into the throttle swtch and set it up so it's in the "enriched" setting all the time and never drops into "idle". Doing that improves throttle response sometimes but is guaranteed to make emissions testing a nightmare. Need to check yours out. If, when you're driving your car it feels like secondaries on a four barrel are kicking in at about 2,500 rpm then your throttle switch is probably OK. If it is completely smooth all the way then it is probably mis-adjusted.
Phantom
 
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