1977 280z prepup for smog check

[240zadmire]

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 

 

[rcb280z]

Engine sounds pretty good.

I don't like that your oil pressure gauge is at "0". Pull the valve cover cap a bit and see if there is any oil slinging around in there. Do it quick, your engine will try to stall out if there are no vacuum leaks.

Edited September 6, 2020 by rcb280z

[240zadmire]

At rest, the oil pressure needle is about 1/8” left of zero.  Cold start, it move up about 1/8” or so and keep it dead zero on idle when engine is warm.  If I rev up to 2-3000rpm, then the needle move to shy of 1/8”.  It’s kind of misleading on the gauge to have 90psi but I don’t think it’s every get more than 10psi.  Will check FSM again.  But I worried before as well but I do see oil sling around.

from what I read, our car love cheap oil. Music to my ears!  What I had in right now is the quake from Home Depot and running 87 octane.  What your recommend oil for our car?

 

regards

 

[240zadmire]

From the schematic diagram, seem like the oil sending unit is connect/relate to the temperature gauge.  Btw, the old oil sending unit and the current new installed behave the same thing.  Might be a connector corroded somewhere !?!??

read that it should be some where in the 35-40psi on normal cruising.  I might need to get a heavy weight oil, say 10w40 instead of Quaker 10w30

 

regards

 

[240zadmire]

The battery has been bother me a while as it is freely moving around when turning... 

poor man’s billet battery tie down.

Should help the visual smog check

 

material:

- 1 1/8” width x 1/8” thickness and aprox 10” length.  My battery width is 7”

- grinder with cut through blade

- sanding disc for grind the sharp edges

- old battery rod with end screw and hook

- some left over aerosol paint can

- a gallon of sweat

Be sure to bend the middle a bit upward to create a “spring” to help tie down without too much force at one end 
 

Edited September 7, 2020 by 240zadmire

[240zadmire]

I have a little exhaust leak right at the connector from the end of the catalytic toward the muffler.  Boy, it took me couple of days to find it.  It’s embarrassed, I know.
 

Then old one were paper like instead of the new ones I installed.  The new ones are fel pro and feel like aluminum/metal.  I notice the flange is not flat anymore.  Perhaps due to heat/cold it deformed.

 

what is your recommendation? Paper or metal exhaust gasket?

 

new ones look look like this.

 

[Mark Maras]

 The metal FelPro gasket is my choice. Have you considered trying to straighten the warped flange? An oxy-acetylene torch, hammer and dolly would probably get it close enough to seal.

[240zadmire]

read somewhere people prefer paper gasket but for the manifold to the head.  Some say soak into water half an hour or so to soften so it will mate nicely to the cylinder head.

as for my problem, yes.  Hammer, dolly and a torch did make the flange straighten better.  Of course oxy-acetylene would be nice.

down the road, I will need to replace from the catalytic and new muffler.  Also, read somewhere that I cannot touch exhaust manifold and the down pipe to the catalytic.  Something with the smog rules in California.  This makes me worries.  I probably understand the exhaust manifold being stock as it keep helping the heat and recirculate the unburned  gas.  But what if the down pipe to to catalytic is too rush, were doom?

 

regards

 

[240zadmire]

While waiting for the DMV permission slip to take the car for smog... bought the mechanical oil pressure gauge because my oil pressure gauge on the dash doesn’t seem to response.  At cold start, maybe 1/8” from zero and as the car warm up, the needle almost point to zero.  
 

- new single pin sender or the old one behaves the same.

- oil weight is 10w-40 Lucas high zinc

- oil filter is K&N

 

hook up the mechanical gauge and at cold start, around 25PSI and as the car warms up and idle, around 8PSI.  Rev up the engine seem to be very responsive.

I guess there is something wrong with the gauge on the dash? Perhaps a resistor need to replace? But resistor don’t fail that often.  Any thoughts? Am I too annoying? Just forget it ?

 

regards

 

[grannyknot]

It might be time for a new oil pump, it's a pretty easy job to do, drop the sway bar down from the rail mounts and you have access to the 4 bolts holding the pump on.  8psi at idle is the lowest you would ever want to see, I'm sure there are engines that function on less but why risk it.

The engine looks great.

[240zadmire]

@grannyknot

you mean I just wasted a new $0.50 oil pump gasket?!?! ?

Folks here seem to incline a turbo oil pump from 280zx of 1982-1983.  I don’t think any definitive of auto or manual trans turbo oil pump.  What’s the recommendation? Get an oil pump from a auto trans or a manual?

 

regards

 

[Zed Head]

That movie is way too big to download easily.  Lower the resolution or just make it shorter.  It was 520 MB.  Took a few minutes and I have decent internet speed.

I saw it get up to 40 psi but it should have been higher.  Could be the oil pump but the other reason for low pressure is low resistance to flow from worn parts, like crankshaft bearings.  But an oil pump change is worth a shot, to start.

Turbo pumps are high volume pumps, to make up for the oil diverted to the turbo.  You shouldn't really need it.  You might just drop the one you have and check it.  There are specs in the FSM.  Take pictures if you find ravaged parts.  Entertainment for the audience.