That is super-close.  Don't do anything drastic.  

Have you been driving the car much?  Have you given it a good hard run or two?  Your first post in this thread shows that you've basically rebuilt the engine.  The rings are probably not even seated yet, so some of that "richness" showing could just be oil burning.

Failure of CO is usually high fuel delivery, excess fuel.  I have a CA 75 and it has always run rich. I would usually lean out the AFM  and that would usually do the trick.  Also,  check your PCV valve and make sure it's working and not stuck.  OOPS, didn't see zed's comment. That's a good idea to drive it at HWY speeds for 10 miles or more before going to smog .

 

Edited October 3, 20204 yr by zclocks

  On 10/3/2020 at 9:58 PM, Zed Head said:

That is super-close.  Don't do anything drastic

Indeed it was super close! 😉

Yep, the engine is practically new, at least for me as I replaced everything possible.   I’ve driven perhaps a 100 miles collectively since the rebuild.  Today, I drove about 50 miles (freeway and surface street) for an hour or more straight.  Probably about 30 miles was on freeway and I was doing 70-80 mph as freeway was pretty empty in the morning.

the piston rings probably not seated in yet.  Perhaps I keep the car idling to burn few more gas tank before the next check.

 

Don’t know if it matter but I had to wait a good 45 minutes at the smog station as it was busy today 😞 

  On 10/3/2020 at 9:59 PM, zclocks said:

check your PCV valve and make sure it's working and not stuck. 

The PCV valve under the intake manifold is  old/new.  I bought that new 3 years  ago to resuscitate the car back from it 12 years winter sleeping.  It was barely used so I thought I can reuse it again.  Will double check and replace it if need be.  
btw, I will follow up on the other thread about the clock.  The quart clock in the car is exceptionally accurate!

 

Much appreciate for all the suggestions 

regards

 

Here's a pic showing some general emissions levels with respect to mixture ratio:

 

I don't know who created that diagram, so I can't credit the author. I do know that Hoover @240260280 posted it a couple years ago. Thanks Blue!

Does is stumble when idling if you remove the valve cover oil cap? any change when removing the dip stick?

Edited October 4, 20204 yr by Dave WM

@Captain Obvious look like the magic number is somewhere between 14.5 to 15 ish.  How do you measure it? Is that a special equipment to connect to the AFM wire or something to get a reading?  I saw a clip on YouTube a gentleman actually install a 02 censor to the down-pipe to adjust his idle ... I don’t really want to go that route.

 

@Dave WM remove cap or oil dipstick does lower the rpm but still running.  I’ll take a video later.

 

I read howto adjust AFM from this site.  
https://atlanticz.ca/zclub/techtips/afm/index.html

But I’ll hold off on that for now.  I’m hitting the FSM and the fuel bible first.  Let see if all measure numbers are within the specified.  Will post update

 

regards

 

One more thing, I didn’t replace the harmonic balancer as I visually inspect it seem to be in good condition.  Also, the gas tank was 91 octane instead of 87.  Some say 87 is out friend but I don’t know.

 

regards

 

As I’m rechecks all the steps in the FI Bible, page 54 is describing how to check the coolant temperature and it’s resistance...

how are you going about checking at different ranges?warm the car and keep tap on the coolant temperature and turn off the car and take measure?

 

regards

 

p.s. (prescript) - every connection along the path to the ECU can add resistance.  So clean them all, even the ones at the ECU to make sure you have the lowest resistance possible.  Don't miss the bullet connectors by the fuel rail.  Take your measurement first though so you'll know if things got better after cleaning and you have a better chance at emissions.

The shape of the curve won't change.  If you're in spec at one temperature you'll be in spec at another.

People have noticed though that some sensors run differently than other sensors.  In other words, the whole curve is moved, so some run leaner or richer.  So, if you find that your sensor is at the high end on resistance and you want to take a chance with $28 you might just buy a new sensor and see if it's leaner than the one you have.

https://www.thezstore.com/page/TZS/PROD/classic17b08/11-3450

Edited October 5, 20204 yr by Zed Head

Did some fuel PSI measurement just to rule out if too much PSI.

Without starter’s solenoid connected, a hair over 40 PSI and approximately 32 PSI on idle.

 

The water coolant temperature is about 88F and resistance approximate 1.7K Ohms

Air temperature sensor resistance on page 52 is approximate 1.9K Ohms.  I read somewhere saying that temperature sensor and air temperature sensor resistance should be close to one another.  The different between the 2 is about 200 Ohms. Am I on the right path?

 

The PCV is working fine, I think.  Pull the hose off and I hear hissing.  Close the end with a finger felt great sucking.  

 

As for the temperature sensor, it kind of old/new.  Got it 3 years ago to fix the idle issue and it was barely used.   I can get a new one but can you tell me if the numbers above look good?

 

Before and after sanding/clean he bullet connectors of the temperature sensor gives similar resistance.  A few ohms less after clean up.

 

One more thing, page 56, saying pin 34 should be battery voltage, however, I only got 11.56v vs 12.78v on battery.

  On 10/7/2020 at 3:32 AM, 240zadmire said:

Did some fuel PSI measurement just to rule out if too much PSI.

Without starter’s solenoid connected, a hair over 40 PSI and approximately 32 PSI on idle.

Those are kind of high.  People have noticed that some of the aftermarket FPRs run high on pressure.  It should be 36.3.  Your pressure readings of 40 and 32 would make it a little bit richer.  FPRs are expensive though and there's no guarantee a new one would be right.  If you can find another for cheap, maybe on craigslist or eBay or here on CZCC, to try out it might be worth it.  A little bit here, a little bit there and you'll hit the numbers.

Forgot to ask about your AFM.  It's a stock Nissan part right?  Some of the aftermarket AFMs run rich.

Edited October 7, 20204 yr by Zed Head

@Zed Head

i noticed when rev up the engine, the PSI did increase pass 40.

you’re saying at ignition on without cranking the engine, it should be 36.3?

  On 10/7/2020 at 3:54 AM, Zed Head said:

FPRs are expensive though and there's no guarantee a new one would be right.

That’s a bummer ;(

dont new ones have to go through QC? This is not good news!

 

what do you think about crimp the line to make it more restrictive to lower the PSI? Anybody use the inline adjustable PSI?

Btw, the AFM is stock.  Though the black cover is removable.  Previous owner might have take a look inside.  I don’t see any tampering and it looks very clean

 

 

thanks 

Edited October 7, 20204 yr by 240zadmire