I have a 1995 Isuzu pick-up, 4-cylinder (2.3l) with a 5-speed
transmission with about 80K miles. A few months ago the engine
started to stumble coming off of idle. Then, the check engine
light would come on as I'm driving with an associated loss of
power. Removing my foot from the gas pedal and re-applying
(usually) made the check engine light go off and the engine to
regain power. The problem gradually became worse and the engine
finally stopped running. Currently, it will not start.
By shorting the two wires behind the left kick panel I was able
to retrieve the error codes,
12 No tach signal to ECM
44 O2S lean
45 Oxygen sensor (rich condition indicated)
I believe that the original oxygen sensor is installed
(I am the second owner of the truck, purchased it with 10K miles).
However, I understand that a faulty oxygen sensor will not
cause an engine to not start. So, I'm trying to understand
how the computer gets the engine speed input signal. I have
removed the distributor, but found nothing obviously amiss.
I don't know how to properly troubleshoot the distributor, not
having a wiring diagram of it. I assume that the engine speed
signal must originate with the distributor, perhaps not.
Any help would be appreciated.