Will someone in simple terms explain to me the meaning, and the differences in open loop, and closed loop.....I realize that this may sound silly, but I am just getting my feet wet in the Prom stuff...Also is there a website that goes into this in detail, BUT for a beginer..???? I read some of these post on here, and it is all Greek to me...I see dollar signs ($) used for certain things....Anyway thanks for any help on this subject......Tom

 

Yeah. The website is www.thirdgen.org. Go to the DIY Prom forum and check out the stickies.

 

open loop is when you first start the car. in open loop the o2 sensor is ignored

once the o2 sensor warms up the car switches to closed loop and uses the o2 sensor to adjust fuel

 

Got it......

 

I was told that open loop meant that the engine was running off itself, meaning the computer had no effect on anything, it was just letting it run

and closed loop meant that the computer controled AND adjusted all aspects of the engine's performance...


correct me if im wrong anyone

 

Read the stickies!!!!

In open loop the computer is controlling the fuel, spark, etc. It just can't use the O2 sensor to get the feedback to see how close what the computer is telling the motor to do is working.