1978 280Z - Won't restart when hot, all interior gauges, fan motor, backlighting not working

[Captain Obvious]

So just make sure I understand everything...

You bought an adapter that has female 1/8 NPT threads on one end and male 1/8 BSPT threads on the other end.
And the Duralast sensor you purchased threads nicely into the NPT female end of that adapter.

Is all that correct?

And also, so how does that new adapter fit into the block? Unless I missed something, you didn't mention that.

[Captain Obvious]

Oh, and to answer your question "I guess my end question is, how can I tell if this Duralast sensor is NPT or BSPT?"

The answer would be "Use a thread pitch gauge". The 1/8 NPT is 27 threads per inch, while the 1/8 BSPT is 28 TPI.  The two of them should be easily distinguishable with a gauge because the thread pitch is different.

But if you don't have a gauge, you should be able to hold the two threads against eachother (with the teeth meshed with eachother) and see the difference. If the thread pitches are the same, the teeth will mesh perfect. But if the pitch is different, they will not.

[NocturnalEmber]

Sorry for the delay all, but I finally was able to get a Beck Arnley oil pressure sensor sent to me. 

I figured while I had the two (Duralast as well) that I might as well do a little comparison between them.

Body wise the Beck Arnley looks to be alittle larger, and there seems to be some sealant over the bottoms of the connector terminals on the Beck Arnley that the Duralast doesn't have. Perhaps the biggest difference is the sheer size of the opening for the oil to flow through. The diameter is huge compared to the Beck Arnley. 

Would this have an effect? I honestly can't say if it would or wouldn't myself, but I'm going to be putting the Beck Arnley one in and I'll report back with hopefully a smoothly running car so this thread can get back to the electrical side of things!

Photos below for comparison for those that are interested:

 

Edited October 1, 2023 by NocturnalEmber

[Yarb]

You’re fine, Did you choose not to incorporate the tee and manual gauge. That and a fuel pressure gauge after the main fuel filter will help you with diagnostics in the future. IMO

[NocturnalEmber]

3 minutes ago, Yarb said:

You’re fine, Did you choose not to incorporate the tee and manual gauge. That and a fuel pressure gauge after the main fuel filter will help you with diagnostics in the future. IMO

I haven't had the opportunity to order one yet, but I will likely order the T for a standalone oil pressure gauge.

 

As for the fuel pressure after the main filter, probably wouldn't hurt, but judging by how black the plugs were after half an hour of run time max, I think they are getting fuel lol (though I do understand that its a wise choice to have one tee'd in for diags.)

[Patcon]

The fuel gauge helps ensure the proper fuel pressure. A bad FPR will make your fuel pressure too high which will cause a rich condition

[NocturnalEmber]

10 hours ago, Patcon said:

The fuel gauge helps ensure the proper fuel pressure. A bad FPR will make your fuel pressure too high which will cause a rich condition

I think i was looking around but I was having a difficult time finding one that would fit inline, I supppose one from a company like glow shift would work with an inline T fitting/barb?

 

Also, finally an update for everyone! @SteveJ, I did install the BeckArnley sensor, and it threaded in like what I would think a tapered thread would (worth mentioning, the Duralast one only made it in a few microturns before resistance, so it MAY not be the proper thread for anyone reading this, as well as the size being way off.)

I attempted to start the car, and after a few cranking attempts (to re build fuel pressure is my guess)  the car slowly stumbled to life, idle was reading about 500 rpms...and...the oil pressure gauge actually rose from zero!  Now I have no idea what the actual reading was, but the gauge is actually reading now with the sensor.

 

However, I am still having that previous issue where when I would give it gas, it would only raise by a few hundred RPMs and then hold there with throttle, even if I pushed the throttle further. Was slow to rev as well. Sounded like trying to rev a car with the distributor timing retarded by a large amount if I had to try and put a sound and behavior to it. When I let off it would return to its stumbling "why did you wake me" state.

I turned it off at that point not wanting to push my luck further; I still need to install the ignition switch.

 

 

[Yarb]

Earl’s fittings is where I found mine. They sell a bunch on Amazon as well.

[NocturnalEmber]

Another update! I apologize for the long delay, but I can say the thread is now back on its original track.  I managed to get the ignition switch replaced with a Beck Arnley one.

As for changes, The key positions definitely feel more noticeable moving between them. The car now consistently will click the relays when turned to ON, The BRAKE light in the cluster shines brightly and the seatbelt warning light will also come on and shine brightly and will then will go off after a few seconds.

Unfortunately, the main problem hasn't changed.   I attempted to start the car. I flicked the key to start, the engine rumbled to life and for a half a second then died. I attempted to start it again, and within a second or less of cranking it started, doing its usual pattern of behavior of "why did you wake me": Running rough, Tachometer reading barely above 500rpm.  I attempted to give it gas, and just as before, it would increase the revs by a few hundred (not breaching 1,000 according to the tach) and after about 15-20% throttle, the revs would stop increasing but they would hold at their current state as long as I kept the throttle pressed. If I continued to apply more throttle past this 15-20% mark, the revs would stay the same like I had mentioned, like hitting a small wall. 

At this point I turned the car off again.  I am currently waiting for my fuel gauge to arrive, but as of now, the oil pressure sensor has been replaced as I notated in my last post, and the ignition switch has now been changed out.  Does anyone have any ideas of what I should pursue next?

I honestly thought about looking at the AFM per the FSM, but all I managed to do was check the ground thats bolted to the AFM bracket, and its clean and snug.

[Patcon]

I think starting with fuel pressure and vacuum gauge is the first step

[Reptoid Overlords]

I have had this inline fuel pressure gauge on my car for 3 years.  It seems to be functioning as it should

https://www.amazon.com/gp/product/B07V583TP7/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

https://www.amazon.com/gp/product/B072M33C5F/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

I have a Glow Shift fuel pressure gauge on my Civic and it works great.  

[Mark Maras]

4 hours ago, NocturnalEmber said:

Another update! I apologize for the long delay, but I can say the thread is now back on its original track.  I managed to get the ignition switch replaced with a Beck Arnley one.

As for changes, The key positions definitely feel more noticeable moving between them. The car now consistently will click the relays when turned to ON, The BRAKE light in the cluster shines brightly and the seatbelt warning light will also come on and shine brightly and will then will go off after a few seconds.

Unfortunately, the main problem hasn't changed.   I attempted to start the car. I flicked the key to start, the engine rumbled to life and for a half a second then died. I attempted to start it again, and within a second or less of cranking it started, doing its usual pattern of behavior of "why did you wake me": Running rough, Tachometer reading barely above 500rpm.  I attempted to give it gas, and just as before, it would increase the revs by a few hundred (not breaching 1,000 according to the tach) and after about 15-20% throttle, the revs would stop increasing but they would hold at their current state as long as I kept the throttle pressed. If I continued to apply more throttle past this 15-20% mark, the revs would stay the same like I had mentioned, like hitting a small wall. 

At this point I turned the car off again.  I am currently waiting for my fuel gauge to arrive, but as of now, the oil pressure sensor has been replaced as I notated in my last post, and the ignition switch has now been changed out.  Does anyone have any ideas of what I should pursue next?

I honestly thought about looking at the AFM per the FSM, but all I managed to do was check the ground thats bolted to the AFM bracket, and its clean and snug.

 I ran into this problem of the engine hitting a wall. I was on the freeway when the car slowed to 45 mph, Wouldn't go any faster regardless of which gear it was in. It would free rev to 6000 with no load. It turned out to be a partially plugged fuel filter. The fuel pressure (mechanical pump) was fine but the fuel volume was restricted. 

 Have you tried a fuel volume test along with the pressure test?