QUOTE(nihil44 @ Feb 15 2018, 10:27 PM)
Got it.
Thanks
Will check on the car.
I am a little suspicious of the CHT sensor. Will also check that after a hot run
Thanks again
Click to view attachmentThis may help
Bosch L-Jetronic Fuel Injection System Basics
Ambient Temperature Sensor (S5) (aka. air intake temperature)
Function: Measures intake air temperature (air density).
Location & Operation: In the air meter, a NTC thermistor (temperature sensitive resistor) sends a signal to the injection ECU. Air density and air flow are used to calculate air mass and control fuel injection duration. Cooler air is denser, and requires a richer mixture than warm air.
Failure: Causes poor fuel mileage.
Test: For resistance rise & voltage drop at ECU pin 27 (ARM 04-23) when using a hot air blower versus ambient temperature (cold=high voltage, low ohms / hot=low voltage, high ohms / @20°C = 2.6 kohms, 2.6 VDC). Or use an ohmmeter to measure the resistance across the two pins of the temperature sensor.
Temperature F° Resistance Ohms
14 7,000-12,000
68 2,000-3,000
122 700-1,000
176 200-400
185+ Less than 200
Temperature Sensor
Temperature sensor resistance
The resistance between ECU plug terminals 13 and 17 (ground) should read 2-3 kOhms at 68 F/20 C. At 14 F/-10 C 7-12 kOhms, at 176 F/80 C 250-400 Ohms.
• Meter reads infinite resistance: Check temperature sensor directly at terminals on sensor. If sensor resistance is ok, replace cables. If tester shows 0 Ohms (continuity) at sensor terminals, replace sensor.
• Meter reads 0 Ohm (continuity): Pull plug from sensor. If meter at ECU plug then reads infinite, replace sensor. If not, replace cables.