Some of those old Nissan ECUs had a screw/pot on the side that you could turn to get blink codes from an LED on the ECU. Maybe the coolant temp sensor is reading too cold and the ECU is stuck in open loop warm up mode?
Voltage on an oxygen sensor is not the major point if it's a one wire sensor I don't one wire system the computer is just looking at whether it is under half a volt or over half a volt and the time it takes to crossover. The early computer systems were simply reading the crossover time as relevat to the mixture. The oxygen sensor can have proper voltage but be lazy and not crossover fast enough.
Correct me if I'm wrong, but I think the fact it's basically pegged at 900mV at idle is showing there's a problem causing it to run rich (the exhaust smells hella rich, too) and while the O2 sensor could be bad, it was reacting reasonably fast so it's less likely to be the issue. The next video will show the MAF sensor is outputting basically nothing, which I'd expect to be in the 600-1200mV range.
Some of those old Nissan ECUs had a screw/pot on the side that you could turn to get blink codes from an LED on the ECU. Maybe the coolant temp sensor is reading too cold and the ECU is stuck in open loop warm up mode?
Voltage on an oxygen sensor is not the major point if it's a one wire sensor I don't one wire system the computer is just looking at whether it is under half a volt or over half a volt and the time it takes to crossover. The early computer systems were simply reading the crossover time as relevat to the mixture.
The oxygen sensor can have proper voltage but be lazy and not crossover fast enough.
Correct me if I'm wrong, but I think the fact it's basically pegged at 900mV at idle is showing there's a problem causing it to run rich (the exhaust smells hella rich, too) and while the O2 sensor could be bad, it was reacting reasonably fast so it's less likely to be the issue. The next video will show the MAF sensor is outputting basically nothing, which I'd expect to be in the 600-1200mV range.
my 1995 is doing the same, I think you have to perform the test with the lines hooked up, If not, the computer is going to give you a bad reading..
The wire is a signal output to the computer. The computer just reads it like the meter is doing.
Oh no don't leave me hanging, what's the fix?
On this one it was the mass air flow (MAF) sensor. I have footage from that somewhere, I really should publish it.
@@YoshimoshiGarage Yeah, that would be great.