D-Jet head temp sensor question Options

[Joe Bob]

Anyone have the specs on the resistor that is used on the 74, 2.0 head temp sensor? I have a lean condition and need the sensor....how many ohms?

[TravisNeff]

Hmm. Here's a snippet from Brad's Djet page. Resistance goes down as the engine warms up, and in my head the mixture would lean out as the engine is warm. As for a resistor for a 74?? Never heard of one.

Normal Value(s):
0 280 130 003 and 0 280 130 012: about 2.5 K ohms at 68 deg. F, less than 100 ohms with hot engine.
0 280 130 017: about 1.3 K ohms at 68 deg. F, less than 100 ohms with hot engine.

I am wrong, here's the data on the resistor, cept' that it is only for 1973.

Function: Biases the resistance of the head temperature sensor across the entire temperature range to cause the ECU to provide a overall richer mixture. Only used on 1973 2.0L's.
Normal Value(s): 270 ohms
Failure Modes
Open: Same effect as an open head temperature sensor (see above). Check with an ohmmeter.
Shorted: Eliminates bias from head temperature sensor. Causes leaner mixture across full range of operation, resulting in drivability problems, possible backfiring. Check with an ohmmeter.
Mismatched or wrong value: Many owners are aware that using a resistor to bias the head temperature sensor is a way of affecting the overall mixture of the D-Jetronic system. Depending on the value used and the setup, you can end up with a lean or rich mixture. Using a bias resistor other than as specified for the 1973 2.0L is only suggested when there is no alternative to obtaining good drivability.
Notes: Used only on the 1973 2.0L engines in the combination of components described above in the cylinder head temperature section. It is used to bias the resistance of the 0 280 130 017 cylinder head temperature sensor. Since the ...017 sensor has a cold resistance value of about 1300 ohms, and a warm value of less than 100 ohms, use of the ballast resistor increases the value the ECU sees at both extremes by 270 ohms. If this resistor is missing from a 1973 setup, the mixture will be too lean across the whole temperature range. Use of this resistor in a 1974 setup will result in a rich mixture when the engine is warm. Make sure that if you have a 1973 setup as described above, that this resistor is present, and if you have a 1974 setup, that it isn't installed.