Further to my earlier posts concerning a 1990 RRC 3.9 which died when I opened the throttle from over-run and my assumption that the Throttle Position Sensor was duff; I have now tested as much of the EFI system as I can.
Thus I used the 1988 model year supplement as that seems to have the same sensors as mine, i.e. no Thermotime switch but does (unlike mine) have Catalytic converters.
I made the following tests using a Fluke meter:
[9] & [10] Injectors resistance = 4 R Correct
[11] Fuel temp sensor = 3K5 @ ~ 10 degC and 4K9 @ ~ 3-4 degC
These might be the correct values but the test page only suggests these figures: 0 deg C= 5k7 - 5K and 20 deg C = 2K4 - 2K6
[12] Coolant temp sensor = 5K @ ~ 3-4 degC. Same commensts as [11]
[13] & [14] Air Bypass Valve = 48R Correct
[15] Throttle potentiometer = 5K6 Should be 5K but is only deemed faulty on open circuit.
[16] Throttle pot voltage range = 280mV to 4V6 Should be 290mV to 4V6
[17] Airflow sensor o/p = 355mV when using the earth in the EFi module loom or 374mV when using a less than handy bolt head as earth - odd that it should be higher with a potentially poorer earth. The pass value is between 300 and 600mV.
Any thoughts from the experts?
Cheers
Richard