When you disconnect the battery in a 1990 240sx Fastback for a long period of time, does the ECU (computer) need to relearn its settings for Timing/ Ignition? Does driving it around help it learn its settings? I am a newbie plz have mercy :-)
-Chris
ECU Question
when the battery is disconnected, the ecu loses it's stored data...but that doesn't mean it doesn't have any information to keep your car running properly. there are default settings that are applied. Yes you do need to perform relearn procedures. just warm the car up to operating temp and take it out for a gentle drive, bring up slowly up to 60mph and then bring it down, repeat a couple of times and the ecu will adapt to what the sensors are telling it.
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Think of the learning as the ability to change the permanent memory values [correct timing and injection duty cycle for a brand new engine at 68F and sealevel by a maximum of 20% in response to the average values returned by the O2 sensors.
Normally the fuel trim correction is +-10% depending on temperature of air/altitude and injector dirtiness.
The learning is pretty fast after you get to cruise a minute or 2........usually WOT is not affected by the cruise memory trims as these values are calulated by MAF voltage.
Normally the fuel trim correction is +-10% depending on temperature of air/altitude and injector dirtiness.
The learning is pretty fast after you get to cruise a minute or 2........usually WOT is not affected by the cruise memory trims as these values are calulated by MAF voltage.