closed loop/open loop
02-27-2005, 10:04 PM
#41
Le Mans Master
Member Since: Jan 2003
Location: Portland Oregon
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Originally Posted by scorp508
Constants table of ECM code. Like the ones I posted up a few posts.
p.s.
I looked the stock '87 values and they are as follows
Hot Engine O2 Timer: 066 Seconds
Warm Engine O2 Timer: 206 Seconds
Cold Engine O2 Timer: 300 Seconds
p.s.
I looked the stock '87 values and they are as follows
Hot Engine O2 Timer: 066 Seconds
Warm Engine O2 Timer: 206 Seconds
Cold Engine O2 Timer: 300 Seconds
You can change these values easy enough.....but if the engine has the old non heated sensors it won't do any good as far as closed loop is concerned because the ECM won't go into close loop until it sees valid data from the O2 sensor. in the later OBD1 and up PCMs they do go into Closed loop much faster but they have heated sensors which does make a difference. The last LT1 I was tuning this week for a blower would go into closed loop as quick as 45 seconds after start up, even then it would depend on how much the O2 sensor cooled off between starts.
