Thermostat is only a few months old, changed it after it got a little hot under the collar on the way to and on a skid pan

The sensor for the temperature guage only has one wire. Electric choke doesn't use a sensor.

What year is your ute? The earlier ones did not have a switch like the one in the photo. Neither did 1200 cars.

It is a 1984, Australian delivered.

OK. . .

From a bad memory:

Follow the wires, should go to a solenoid mounted on the front of the intake manifold.

This solenoid is rigged inline to the distributor vacuum canister.

This solenoid does not open until the temp has come up and stops the vacuum advance working until such time.

I think this same solenoid may have a feed from the gearbox as well that only allows vacuum advance to operate in the top 2 gears.

Sorry I can't be more help as most of this stuff falls off my datsuns. . .

This would also explain the drop in temp due to the increase in advance since this wire has dropped off. The extractors will help also.

Thanks for that, it probably explains why it is running bad now as well. It feels like it did before I adjusted the timing.

Now to find a replacement!

Does it have anything to do with a little spring loaded butterfly that is built into the old (original) exhaust manifold? A picture may speak a thousand words in this instance but I don't have one handy!

The butterfly valve in the exhaust manifold is called the Heat Riser (Nissan calls it the "heat control valve"). It only has an effect when the engine is cold, so don't worry about it not being there now that you have extractors.

easy soulution. find the solonoid that this sensor opperates, bypass it with a piece of vacuum hose and be done with it. that way you'll have vacuum advance all of the time instead of just in 3 and 4 after it has fully warmed up. the reason why it was installed in the first place, is because most people don't regularly maintain thier vehicles and when they don't tailpipe emissions go way up. bypass it, keep it properly tuned, and get better performance in the long run.
that way you wopn't be spending a bunch of money for something that you don't really need.

Cool, thanks dd One less thing to worry about.

Quote:Don't worry about a replacement for the electrical switch in the picture.

Just hook the distributor vacuum line directly to the port on the carb. Use a plain hose, if there are any round fittings in the hose, remove those or use a longer one-piece hose.

This will bypass the "spark timing control" system, the main part of which is the solenoid on the front of the manifold in this picture:


engine

The 1972 Datsun 1200 (north america) has the same/similar solenoid called the "vacuum cutting valve solenoid". It controls the vacuum advance line, it prevents it from advancing under certain conditions. It's for emissions controls and not great for performance. It's like disconnecting the vacuum advance.

However, if the solenoid is "off", like the wires are disconnected, then it's all OK. Then it can't affect the vacuum advance, so no worries.

That is, if that's what that temp-switch controls. Older models used a thermo-vacuum switch in the same location (but you have an electro-switch there).

oops, didn't see rgrinder's post. I agree with what he said.