cyl. head temp sensor has 2 terminals. single wire coming out of harness. can it be altered or do I need new sensor ?

It may be a dual sending unit. I am not sure though. If it is, you should be fine just plugging into one terminal.

Someone correct me if I sound like an idiot....

T Sensor 2 has a single wire, as does the pigtail from the harness. T Sensor 1 (on the intake manifold) has 2 pins, and so does the plug in the harness. They're about 2 feet apart, so it's unlikely they can be mixed up. Pictures would help.

The Cap'n

pics? do you mean oem sender for the fi system or aftermarket sensor for a gauge? for a gauge sender there are 2 wires, for the oem sensor there is one wire..

I can't tell if you're talking about the sensor that goes under the spark plug for the CHT gauge or the sensor that screws into the head for the ECU.

refering to sensor that screws into head for ecu.

Should be single wire with a in-line resistor.

has vdo quartz temp gauge on center console. will try to trace wiring from it tomorrow but I know we dont have a resister pigtail if its required on two terminal hookup.

There is no 2 wire sensors for the ECU head temp. The two wire is for a vdo gauge only. Won't work with a ECU.

should I forget the gauge and order the sensor for hookup to the ecu ?

the only real way to use the gauge is with the thermocouple ring under the spark plug unless both your heads are tapped for the 2wire. The stock one goes in behind the rear intake tube on the passenger side. You will need it for the stock fi to work, as well as the resistor. Check http://members.rennlist.com/pbanders/ for part numbers and resistor values. The resistor can be had at radio shack.

factory set up for the temp gauge in the console is that it is an oil temp gauge not a head temp gauge. The oil temp gauge is connected to a sensor in the oil sump/bottom of the engine and is commonly called a taco plate sender (mentioned for searching purposes). The VDO head temp gauge is aftermarket (so no wiring is present in a stock harness) and is a 2 wire item (so you have to run it) with a sensor located under the #3 spark plug (preferred location)