Jump to content
240zadmire

1977 280z prepup for smog check

Recommended Posts

Hello everyone,

 

I'm at the state of getting the car for the smog check and would like tips and suggestion to get the car smog check pass the first time around.

History of the car:

Long story - short and for lack of better words, I don't consider the car is restored to its glory days nor do I consider myself as car restorer.  I am at best is improve the car from a none-ops, none working to operational, working state base on my standard.  If you saw some of my posts, you'll notice I'm more of a monkey see monkey do without a brain sort of speak.  Grease elbow at best and lot of times did stuff wrong or reverse.

 

What I did to the car.

Engine:

- Replace piston ring set using Hasting parts

- Replace valve seal, valve spring set

- Polish cam, shaft, hone engine (all manual by hand, by me)

- resurface header (machine shop)

- replace all engine bearing and seals

- check engine cylinder to the specs base on FSM (primitive, cheap tools)

- spark plugs and spark wires

- thermostat

- radiator hoses

- reuse fuel injectors

- replace all fuel injectors hoses

- new head gasket

- oil pump gasket

- oil sending unit

- new fuel filter

- new connectors (fuel injector, water temperature, CSV, throttle body ...)

- cleaned and DeOxit Gold 5 for all connectors.

- Air regulator clean up

- new ignition coil

- air filter

- fuel hoses replaced

- vacuum hoses replaced

- heater hoses replaced

 

Body/suspension/brake:

- Replaced KYB Excel-G on all.

- Replace all bushing include the 2 spindles on the rear (the ones that uses index and thumb to pull out as described in the manual.  Who needs sled hammer, torque and lot of rant and foul language to get it out???! Professional does that.  Real men just use a thumb, push one end in and pull the other end ?)

- ball joints

- outer tie rod ends

- both front and rear wheel bearings

- new brake pads and shoes

- new rear brake cylinder

- rebuild front brake cylinders

- reuse master brake boost

- new master brake

- new clutch

- new clutch cylinder

- new fan clutch and water pump

 

Electrical

- All lights/gauges seem to work.  I mean, they light up and gauges movement.

- all light bulbs replace where possible.

- KEEP the Fuel light bulb as is.  DO NOT change to LED.  You're asking unnecessary problem to your list.

 

Exhaust

- Muffler probably original or at least decade old

- Catalytic probably original or decade old

- exhaust pipe show external rusting but no leak

- No white smog when start the engine even in the morning.  (Morning in Southern California is like high noon somewhere else.  Nevertheless car start up high RPM and drop down in minute or so.  Car starts every time, morning or warm)

- no foul smog smell.  Though the smog definitely stronger than modern car/sedan.

- spark plugs seem to be OK as no black powder on the tip nor white color.  I think the engine is running on the rich end rather than lean.

 

The car is mostly idling and rev up every now and then in the garage.  It ran 30 mins to an hour each time depend on what I had to do in the garage.  When the car is off the garage, at most I driven was 30-35 mph in residential area.  Since the car is back to life, I've driven approximately 15 miles total.

 

Original parts:

- 5 speed.  I did nothing to the transmission except replace the oil

- Fuel pump

- Fuel sending unit

- all the gauges

 

Differential:

- took a part, clean up, and new oil

 

Not working part at the moment:

- AC

As you can see, I'm merely replacing wear and tear parts.  The only thing that I needed machine shop involved was to resurface the cylinder head.

 

I'm sure you guys gone through this thousands of time.  Question is, what is your secrets or tips to get the car pass smog?  Do I need to do more? replace catalytic, muffler ... 

 

please share your experience

 

regards,

 

 

 

Share this post


Link to post
Share on other sites

Looking at what you've done, I think you have a strong chance of passing. 

I am a little concerned about you "polish"(ing) the cam by hand. Does that mean you  cleaned it up? One of the big mistakes made by guys who have to pass smog is changing out the cam for a performance cam. Trust me on this, you will not pass. Ever. 

If it were me, I'd have sent the injectors out and had them cleaned and flow matched. If they are clogged and dribble fuel into the cylinders you won't get good burn. 

So here is the process in California for older cars. You may have to get on the rollers so that will make a difference as to what shop you go to. Definately, if you go outside of the county you live in, you will have to go on the rollers. There will be a visual check so everything that was there the day it left the factory must be there the day you smog it. They will stick the sniffer in the tailpipe. Do yourself a favor and find a shop that will give you a precheck. They may charge you for it but don't complain. If you will not pass, they will tell you then and you will not have a failed test to alert ARB. I own a shop in Sonoma, (I do anesthesia not smog tech) and I pay almost a $1000 a month for equipment leasing. So you insult me if you ask for a free pretest. 

Good luck!

Share this post


Link to post
Share on other sites

@conedodger

sorry for not being clear.  The cam just clean up and “feel” with the finger nails to see any groove or hill.  Just cleanup and wrap a 3000k sand grid where it meets the tower and use the shoe lace run on it a few time. I don’t think it made a dent.

 

for the crankshaft.  Same thing.  Wrap around the 3000k sandpaper, loop shoe lace a few round and pull the shoelace back and forth couple of times.  I watched YouTube and people did that.  I’m just like new believer in a cult.  Just do it whether it make sense or not.   I don’t why people on YouTube keep saying it’s a must to rebuild the engine... blah blah blah.  Take it to the shop to have actual equipment and measure the out is specs... I guess that.  Pulling shoe lace for hours on end, perhaps made some dent... The crankshaft must be 50lbs running thousands of RPM for years with direct metal bearing contact granted lube..... and it is still one piece let alone a few shoe lace pulling.  The sandpaper disintegrated long before it will made a dent.... what do I know.  I’m a new believer in a cult.  I’d do anything if I may say so.

No free pretest.  Honest work!

 

like I said, I’m it is not a rebuild/mod by any stretch.  A simply improvement to the deteriorate parts by replaced them.


regards

 

 

Share this post


Link to post
Share on other sites

Another thing, for the valve job. I did put the grinder material on the lip, use the drill attach to valve stem with a rubber hose and pull the trigger for a few seconds.  Again, Religious rather than science ?

about roller, there isn’t a temporary permission for driving the car to smog test center?

Share this post


Link to post
Share on other sites

The place to start is to tune the engine to Nissan FSM specs.  Set timing, valve lash, etc. exactly as Nissan says.  If you have a catalytic converter make sure it's in good shape.

With the factory stock EFI system there's not much that you can do except get it as close to what the factory sent out the door as possible.  The 280Z's were designed to pass emissions.  Everything about the tuneup procedure is to get them emissions testing ready.

Share this post


Link to post
Share on other sites

I'd start with the Google machine.  Seriously.  I know that they get clogged if they see a lot of fuel over time, but don't really know if the materials inside change over time.

Do you know what your regions emissions tests entail?  Some states have different rules for different regions.  In Oregon all I needed to pass was idle emissions.  But even just that was difficult.

Edited by Zed Head

Share this post


Link to post
Share on other sites

2 hours ago, conedodger said:

So here is the process in California for older cars. You may have to get on the rollers so that will make a difference as to what shop you go to. Definately, if you go outside of the county you live in, you will have to go on the rollers. There will be a visual check so everything that was there the day it left the factory must be there the day you smog it. They will stick the sniffer in the tailpipe. Do yourself a favor and find a shop that will give you a precheck. They may charge you for it but don't complain. If you will not pass, they will tell you then and you will not have a failed test to alert ARB

All good info here.

You will be on the rollers with a 15 mph and then a 25 mph run for a specific time. Pre-check is very important. I would be ready to replace your cat. It's what I had to do 4yrs ago. They also test the evaporative system as well in southern ca. So make sure there are no issues there. I needed a new gas cap for my 77 on my last test. 77 and 78 caps are different as you will see when you go to pay for one if it is needed. Something about a little check valve and thats all I remember. Surprised I remembered this much. 

And a tune up like ZH suggested wouldn't hurt. 

Before my last test I took it out on the freeway and blew it out, got the cat hot. Was told it helps.

Good luck!

Share this post


Link to post
Share on other sites

Have you noticed I misinterpret rollers as in put car in a trailer and haul it to the smog... silly me.;) all good info.  Definitely will look for the pretest station.

 

in California, there is a regular smog test station and there is the STAR only test station.  I had the yearly reminder letter from DMV saying if I want to drive, I need to pay x amount.  It didn’t say I need smog test on the letter.   But I believer even if I pay the x amount, they will send a letter asking for the smog before issue the sticker.  I misplace or lost the letter

 

should I just pay DMV and wait for next set of instructions ? 

Share this post


Link to post
Share on other sites

I drove the car around the neighborhood for a good 45 minutes.  Top speed 35mph when allow.  Took the adventure to highway and able to do 70mph for a good 2 miles.  What a rush.  Don’t tell cops I did that please.  Brought the car home and while it is idle, took a temperature at the catalytic ends.  The end from the down pipe is about 330 degree Fahrenheit.  The end to the muffler is way up to 560 degree Fahrenheit.  Right where it connect to muffler drops to 320 degree Fahrenheit or so.  The exhaust manifold from the engine is 770 degree Fahrenheit.  
 

so the cat is working as expected as it cook the smog longer before it release to the muffler/air?

can someone explain the science in layman term?

It is really interesting learning new stuff 

best regards

 

Share this post


Link to post
Share on other sites
All good info here.
You will be on the rollers with a 15 mph and then a 25 mph run for a specific time. Pre-check is very important. I would be ready to replace your cat. It's what I had to do 4yrs ago. They also test the evaporative system as well in southern ca. So make sure there are no issues there. I needed a new gas cap for my 77 on my last test. 77 and 78 caps are different as you will see when you go to pay for one if it is needed. Something about a little check valve and thats all I remember. Surprised I remembered this much. 
And a tune up like ZH suggested wouldn't hurt. 
Before my last test I took it out on the freeway and blew it out, got the cat hot. Was told it helps.
Good luck!

I concur with rcb, your cat could be a concern.
Do the FSM tune up (if anything, tune it to run a bit leaner), and be sure to drive it on the freeway (65 mph) for about 30 minutes to get the cat warmed up... then head straight in for testing.
Cats can lose efficacy over time, that can be expedited by using engine oils with high levels of ZDDP.
The good thing is, CA emissions standards are a bit lower for these older cars.
Good luck!


Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

Just google catalytic converter and have fun. There is tons of good info out there.

If you need one you have to make sure it is CARB approved for Ca.

In a catalytic converter, the catalyst's job is to speed up the removal of pollution. ... As the gases from the engine fumes blow over the catalyst, chemical reactions take place on its surface, breaking apart the pollutant gases and converting them into other gases that are safe enough to blow harmlessly out into the air.

Share this post


Link to post
Share on other sites

Did a complete tune up based on the FSM.  Went over the fuel injector bible once more time just to make sure.  The Tune Up chapter is talking about dashpot adjustment, well, I don’t have one and mine also a manual tranny.  Another one is to check the CO to have 0.5%.  How do you do that? That is kind of special tool that only shop has?  One more thing.  Adjust BTDC to be 10 degree, my idle is hovering 1000-1200rpm and the screw adjustment on the throttle body is all the way down.  Is there another screw somewhere to lower RPM to 800 base on the FSM?

 

another thing I noticed is the smog on the tail pipe smell like my Honda Odyssey 2014.  Which is no smell at all.  Which I think is good?  Smell meaning I scoop a handful and sniff with my nose.  I know, I know it is not scientific and stupid even, but somebody got to do a dirty work.  
 

what do you guys think?

 

any feedback is great.

 

regards

 

Edited by 240zadmire

Share this post


Link to post
Share on other sites
7 hours ago, 240zadmire said:

Another one is to check the CO to have 0.5%.  How do you do that? That is kind of special tool that only shop has?

my idle is hovering 1000-1200rpm and the screw adjustment on the throttle body is all the way down.  Is there another screw somewhere to lower RPM to 800 base on the FSM?

Yes, the carbon monoxide percent is measured with a special meter.

It sounds like you're doing pretty good. The only thing that you might still have to investigate is your idle speed and the position of your idle screw. If that screw is all the way down and you're still idling at 1000-1200, it's an indication that you've got vacuum leak(s) somewhere. I suspect it's a bunch of little leaks spread throughout the system. Rubber boots, small cracks in hoses, injector seals, throttle body and intake manifold gasket, etc.

However, at this point, if it runs good and doesn't stink, you might consider taking it in for a pre-test so you know what you're dealing with. Who knows... If you've got some small vacuum leaks and you would be running a rich idle without them, maybe they'll cancel each other out and you might even pass.

Share this post


Link to post
Share on other sites

I recommend getting a "pre-test" done and ask for a print out and go from there. 

Post a copy of it here.

But then again, if it looks like it will pass as its being tested then go for it. 

Edited by rcb280z

Share this post


Link to post
Share on other sites
14 hours ago, 240zadmire said:

  my idle is hovering 1000-1200rpm and the screw adjustment on the throttle body is all the way down.  Is there another screw somewhere to lower RPM to 800 base on the FSM?

 

 

 

May also be a defect in the AAR. Bleed air to increase idle at start up. I should close down on its own as things heat up. You may want to confirm its operation per the FSM

Share this post


Link to post
Share on other sites
2 hours ago, Dave WM said:

May also be a defect in the AAR. Bleed air to increase idle at start up. I should close down on its own as things heat up. You may want to confirm its operation per the FSM

One of the first things that 240zadmire did was tune his AAR.  Might need to adjust it back now.  Tuning is an iterative process, often things need to be turned back to where they were.

But before doing that you can just block the AAR hose, either pinch it off or disconnect it and plug it, and see if idle speed drops.  If it doesn't there's an air leak somewhere.

Share this post


Link to post
Share on other sites

All great suggestions ladies and gents.

I just did all those things before jumping on the forum.  I narrowed down to 5 places.

the rubber boot surface cracked but not cracks all the way through. 
 

1.  EGR not 100 closed.   I removed the hose while plugged the 2 ends. Rpm slightly lower.  Maybe  50 rpm.    Blow in one end with great resistance but still some air can get through 

2. hose from the valve cover to body throttle has a tiny leak.  Probably at the elbow where it connects to the valve cover.

3. Don’t know the thing call but the thing underneath throttle body that has screw at the end. Under the throttle body has 2 hoses. One connect to the distributor and the other to the canister.


4.  The throttle butterfly flapper rod might have air sip through

5. the vent under the thermostat body where the hose connect to the EGR breather

 

the oil cap and dipstick seem to be ok. 
 

its going to be something obvious that I can’t get my hands/brain wrap around it.

 

pre-test. 100% will do.  If the car has any of my personality, it will almost guarantee fail.  Just like me. Even while I was I school. I did very well up to the exam point.  The professors has to call me out numerous time slapped my hand why I made such stupid mistakes.  They know I knew the subject but never get 100%.

 

sorry guys but I’m not satisfy/give up just yet, not even for the pre-test. Will need to look from another angle.

 

will keep everyone up to date

 

 

regards

 

 

 

  • Like 1

Share this post


Link to post
Share on other sites

Check that AAR.  You adjusted it to give a higher idle when cold.  They don't usually need adjustment, the adjustment screw is glued after adjustment at the factory.  I didn't say anything at the time because it would have just been a distraction.

You might just need to set it back where it was.  Maybe you have fixed some things since then and now your idle will be correct, cold and hot.

Share this post


Link to post
Share on other sites

Hi all

I’ve been so religious lately.  This week alone, I’ve reading bible, well fuel injector that is, couple of time already.  I read, read and reread the high idle section particularly.  Check, test, double check.... I’ve readjust the AAR couple of times a ready, and I don’t think I’ve got to the original factory yet.  I’ve narrow down 2 area that might be faulty.  The AAR and the thing underneath the throttle body.  It calls BCDD (boost control decelerate device) either one or both of these let a little air in.

 

the screw on the throttle body still completely screwed in and now idle is approximately 950.  If the car is fully warm up or rev up a few time.  Idle is 1000 or 1050 or so.  Still not quite yet.  Perhaps I’ll take a closer look at my dead center as well.  Who knows it might be off a degree or 2.

 

stay tune folks. Thanks for all great suggestions 

Share this post


Link to post
Share on other sites

Other vacuum hoses to check are the brake booster hose and the supply hose to the heater valve control bottle.  And the hose to the emissions vapor canister and the distributor vacuum advance diaphragm.  Just pull them off and block the port and see if idle drops.  Some of those arte ported vacuum, so shouldn't affect idle, but they might be connected to the wrong place.

  • Like 1

Share this post


Link to post
Share on other sites

Great suggestion about brake booster... will check late tonight.  Garage is 100+ right now and governor asking resident not to use AC this weekend as the heat wave is sweeping the south land.  Will pack the family into a minivan and use it AC instead till 10pm tonight.  Figure smaller footprint should help minimize stress on the power grid

?? 

Share this post


Link to post
Share on other sites

Hi all,

 

I did 2 major things.

1-  readjust the AAR to the best I could.  I think there still a little air can sip in via the adjustment screw.  Need to find a silicone, glue or something to cover the screw back to where it was before I broke loose the hard glue...

2- took the throttle body out and did an experience as it bothers the adjustment screw should not crewed in all the way....

 

what I did for #2.  Of course with a proper tools such as vacuum would be much easier... I did disassemble the butterfly/flapper to clean the gunk and inside the chamber.   When I reassemble, it might be a hair misalign.  What I did was to pour couple of tea spoon of rubbing alcohol from the intake end and notice the rubbing alcohol sip through.  It sip through very slow, but nevertheless.  Eyes and even flashlight won’t see the gap.  Either use a vacuum or liquid to make sure.

unscrew the 2 screws that hold the flapper/butterfly and trial and error couple of times.  It is not 100% air water proof but much meter.  Little moist able to get through but very very slow.

assemble back at was too late to wake the neighbor up.  
 

fire her this morning and I can see that now I can adjust the RPM to 800.  You might not see the 10 degree retarded but it is.  The rpm is spot on 800.  Another good part is that the air adjustment screw on the throttle body still have a few turn before it all screw in.  I will need to tidy a few wire, check and recheck a few more times before I can bring her to pretest.

Take a look at the video.  There is a high pitch while idling.  Possibly lashing noise, retainer of the valve arms, or just the fuel injectors noise.  I can’t tell the different.

it is a great progress thanks to all the suggestions 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.