Air regulator valve

[TomoHawk]

My fuel gauge only reads about 35 with the engine on. I should check the voltage at the fuel pump? Maybe clean out the pump strainer?

[DatsunZsRule]

Also test your thermotime switch like 280~Master mentioned. that can cause such symptoms. I have to replace the one on my Z because it is bad. After mine is warmed up, and I shut it off and it sits for about 5-10 min. and I go to restart it, she has a devil of a time starting and when it does, it runs real rough for a few min. due to the faulty Thermotime Switch providing ground for the Cold Start Valve when it shouldn't so it's getting too much fuel. Then when that extra fuel burns off, the idle smooths out again. So for sure check that as well.

[DatsunZsRule]

35 is close. FSM says 36 @ idle at least. Cleaning fuel pump strainer, inspecting all fuel lines for kinks and making sure lines are clean, replacing a dirty fuel filter ect. will help improve your pressure if it seems a little low.

Good luck

Sorry 78 280zcar, back to you

[78 280zcar]

I havent had a chance to get over there yet to test the air regulator. How would I go about testing the thermotime switch?

[DatsunZsRule]

Thermotime Switch test:

You will need a thermometer and an ohmmeter.

1) Disconnect ground cable on batt.

2) Disconnect Thermotime switch connector

3) Remove switch from T Stat housing

4) Dip the heat-sensing part of switch into cool water 50 degrees F.

5) when the Thermotime switch is about the same temp as water (50 degrees) measure the resistance between terminal numbers 45 and 46. The resistance should be about 78

6) Now increase your cool water temperature on your stove until it is more than 77 degrees then check continuity between terminal numbers 45 and 46. If your ohmmeter reading increases from about 78 to infinite, circuit is OK.

BTW, the terminal numbers I got from my FSM. Hopefully you know which ones are which If not, I'll try to dig one up

Good luck.

[78 280zcar]

Will an ear thermometer work, that is all I have. It is more like the type they use at the hospital. I have an ohmmeter but just need to figure out which one is 45 and 46.

[280~Master]

Just an update.

I got a new air regulator on my intake tonight and this solved my problem with the idle situation.

78 280zcar yours could be out. I would wiggle the air regulator a bit right where the conection is and if its loose the replace it. Mine was real bad I could totally pull it out of its housing. I was getting the wrong reading.

Good luck,

John

[DatsunZsRule]

I use a meat thermometer. You can pick those up for pretty cheap. Got mine at the grocery store some time ago and still works perfect. They work awesome. I'm unsure about an ear thermometer??

I'll try and get a photo of the end of the switch with the terminals to show you which terminals are which tonight.

[78 280zcar]

280z~master, you dont mean the connection itself, but more like the connection that goes into the air regulator not where the two connections meet, because mine is really loose too, I hope that makes sense. And datsunzsrule, thanks and let me know which connection is which. Thanks

[DatsunZsRule]

Ok, I just snapped my own photo :laugh:

NOTE: whats written above it is part of a different test Hope the picture is clear enough.

[78 280zcar]

Whare did you get that test from it looks good by the way? I have a 78 280z FSM but it doesnt have that test!

[sblake01]

I do believe that test is in the 78 280Z FSM