Dawid van der Walt wrote: ↑Thu Oct 07, 2021 3:16 am
Measuring across 3 and 18, I randomly get a resistance reading. I can't seem to get any reading across 2 and 18.
If you are referring above to pin numbers on the ECU connectors then you are using my text and diagrams incorrectly. For the LH connector the operative pins are 2, 3, and 17. For the EZK they are 8, 18, 26.
And you should test both.
Go back and look at the pictures on page 41 again.
It's best to use the "blanks" (absence of pins) to make sure you have the right pins for the test.
If, as per thread title, you are bench testing the unit, then pin 2 is ground, pin 1 is WOT, pin 3 is idle.
Dawid van der Walt wrote: ↑Thu Oct 07, 2021 3:16 am
What are the symptoms of a failed TPS when driving?
Two basic failure modes: Idle switch, full-throttle switch.
If the idle switch is not closing due to either cable setup or because the switch unit has failed the symptoms are basically 'bad' idle. The exact manifestation depends upon the health of everything else on the motor. If everything else is perfect, the idle will, once the engine is warm, oscillate up and down in time with the oxygen sensor sweep. If motor has other issues then the idle might oscillate wildly, or the engine might just die every time it tries to return to idle from higher RPM operation.
When the full-throttle part of the switch dies, there's no easily observable manifestation. You'll only "see" this failure if you are measuring air/fuel ratios when you are at full throttle. When that part of the switch dies you are, essentially, running "lean" at full throttle.
Dawid van der Walt wrote: ↑Thu Oct 07, 2021 3:16 am
My car ran well on partial throttle, with a slight hesitance around 4500 rpm onwards.
A number of things could cause poor operation at 4500+ depending upon the exact definition of "poor."
This is an '89+ right? Do you have access to a Bosch Hammer or "Theo Tool?" If so, look for knock and/or hall sensor codes.
If not, when were your knock and hall sensors last replaced? What about the crank speed sensor?
Fuel filter health?
Injector health?
Resonance flap operation?
Cap/Rotor/Plug age?
Condition of coil and plug wires?
MrMerlin will next ask you for a picture of the engine bay. And I'd agree.
Dawid van der Walt wrote: ↑Thu Oct 07, 2021 3:16 am
... but could it be the TPS?
Highly unlikely. The only thing I can think of, off the top of my head, is if the idle switch is always closed.
Idle switch failure of the TPS unit is very rare in my experience. Idle problems associated to the unit are usually cable setup. It's the full-throttle part of the unit that dies mostly.
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