Picked up another Turbo Z. No rust on the body, but it has a few issues that need to be taken care of.

Aside from needing a new rack and pinion, the engine idles rough and stalls when the engine is cold. If you allow the engine to run and reach normal operating temperature, it runs fine.

I know it's not the ECU because I took it and plugged it into an 84 Turbo which ran fine with the 85 ECU.

I didn't bother to run the ECU codes because they have been unreliable in the past. For example, they would give codes that you'd expect from an engine that was running normally.

Replacing the Engine Coolant Temperature (ECT) Sensor should solve the problem.

Hi Tx,

Are you referring to the Cylinder Head Temperature Sensor (CHTS) Nissan Part No. 22630-01P01? That's the only sensor on these cars I know of that may cause such an issue.

ECT Sensors have a NTC thermistor inside, which deliver a richer fuel/air mixture at start-up and a leaner mixture at normal operating temperature. That may be the part. They usually go into the block and are surrounded with coolant.

That makes sense. It does smell like it's running a bit rich when it's cold. I can smell fuel and once it reaches normal operating temp. the smell of fuel seems to subside.

The part you're referring to is actually listed as the Engine Coolant Temperature Sensor Nissan Part No. 22630-01P01 on www.nissanpartsdeal.com. Therefore, it appears that would be the correct name for it. Z31 guys like to call it the Cylinder Head Temperature Sensor, but I believe it's the same part.

I think it is bolted into the block above the water pump and to the right of the thermostat on the Z31. I am including the link to the parts website which shows an exploded view of the engine and the location of the part.

22630-01P01 - Nissan Parts Deal (http://www.nissanpartsdeal.com/parts/nissan-sensor-head-tmp~22630-01p01.html?Make=Nissan&Model=300ZX&Year=1985&Submodel=&Filter=()&Location=cylinder-head-rocker-cover%2c111_001%2c22630R)