resurrecting a 1977 280Z

[MM569457]

The first real wash since the 90s.

 

In the end, paint has a few areas of cracking but in decent shape. Will see how a wax will go to remove blemishes here and there.

 

twicepipes arrive tomorow.

Edited March 26, 2023 by MM569457

[MM569457]

Had a friend stop by. Engine tan for 10 minutes. Smoking, but we figure it’s not engine related and most likely dust/ceiling insulation that fell into the header heat shield over the last 15 years while garaged.

 

Temperature gauge isn’t working, but he had a thermal gun and was able to determine it stayed roughly 176°.

 

troubleshooting shows the Guage works, and the sensor has resistance and should theoretically work, but while car is running the gauge doesn’t move.

 

[MM569457]

Twice Pipes arrived a day late. Going to take to a muffler shop to fabricate. The muffler will need some tweaks to be mounted vertical due to the rear bumper.

[SteveJ]

On 3/26/2023 at 7:55 PM, MM569457 said:

Had a friend stop by. Engine tan for 10 minutes. Smoking, but we figure it’s not engine related and most likely dust/ceiling insulation that fell into the header heat shield over the last 15 years while garaged.

 

Temperature gauge isn’t working, but he had a thermal gun and was able to determine it stayed roughly 176°.

 

troubleshooting shows the Guage works, and the sensor has resistance and should theoretically work, but while car is running the gauge doesn’t move.

You will need a decent multimeter to diagnose this problem. Here is what I suggest doing.

1. Put your meter on resistance.
2. Take a reading from the terminal on the sending unit (with the wire unplugged) to ground. I like using a stud on the driver's side strut as the grounding point. Do this with the engine stone cold.
3. Get the car up to temperature.
4. Take another resistance reading on the sending unit. If the resistance hasn't dropped significantly, either you are doing it wrong, or the sender is bad.
5. With the wire to the sending unit still off, turn the key to ON.
6. Put your meter on 1 Amp current. (10 A if 1 A isn't available.
7. Put the negative lead on the sending unit.
8. Put the positive lead on the wire that goes to the sending unit.
9. The current reading should be dancing. (If you look through my videos on YouTube, you'll see a demonstration of this. My channel name is MyZCarLife.)
10. If the current reading isn't dancing, you need to inspect your wiring. Do these steps first and report back. Then I can write up the rest.

Please create a signature with the year of your car. That way I can provide instructions specific to the year of your car for the next phase if necessary. (I know it's in the subject line, but sometimes I have a lot of tabs open and can't see the subject.)

Edited March 28, 2023 by SteveJ

[MM569457]

Found the channel. Going through the steps now.

[MM569457]

With the gauge direct to ground.

 

with it running, it shows resistance but the guage isn’t reading

 

Edited March 31, 2023 by MM569457

[MM569457]

Guage started working, raising the temperature gauge. Then it dipped down to below 120 with the car running.

 

I’m sure it’s a bad sending unit.

[SteveJ]

That sounds like an intermittent connection. On my 240Z I thought I had a sender going bad. I replaced it, and the gauge registered for a little while before it stopped working again. I checked the connector, and it was just barely attached to the wire. I put on a new female bullet, and I've had no problems since.

Did you take a resistance measurement from the sending unit to ground like I suggested?

[MM569457]

I did, it showed resistance.

[SteveJ]

I can probably shoot a demonstration video of the sender tomorrow to give you something to compare readings to.

I believe you're familiar with my YouTube channel.  

[SteveJ]

It was too windy yesterday for me to sit and let the car come up to temperature. I was driving it today, so I did before and after photos.

The interesting thing is the narrow band in resistance between stone cold and operating temperature.

Cold:

Operating temperature (from a very nice drive today)

[MM569457]

Ran the car for 10 minutes. Checked the ohms with two voltmeters.

 

no readings. I changed the wires and checked the grounds. Started the car again and it crept to the 120° and then went back down. Radiator is of course hot to the touch.

 

Edited April 3, 2023 by MM569457