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Old 01-16-2011, 04:02 PM   #801
zebra
just can't seem to leave
 
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Drives: your mom wild!!
Join Date: Oct 2008
Location: cold & windy
Posts: 11,588
Quote:
Originally Posted by Huggerorange73 View Post
Damn, you guys made me drag out all my notes and books from my classes I took

When a car is started, the computer is in open loop until certain criteria is met. The o2 sensors need to be heated to work properly, so this is the main reason there is a delay.

After the sensors are heated up, the car goes into closed loop and the O2 sensors make their corrections.

The computer will go back into open loop under a variety of conditions. Throttle Position (TP) is one way.

There are parameters in the computer that determine what the TP is for Open Loop, and other things.

When that TP is reached, and the car goes open loop, and richens up.


In closed loop fueling, the computer takes readings from the oxygen sensors which read +/- of 14.64 AFR (Stoich) and makes corrections for it. If your car is idling @ 13.5 AFR, the 02s can see this, and will know to pull out enough fuel to get back to stoich.

In open loop, the fueling is purely based off the MAF transfer function and the open loop fuel table. This table has to be calibrated any time you make MAF changes, and changes that affect the airflow of the MAF.

With that being said.....as long as the 02 sensors are warm, he's in the loop..given the fact they are heated, it's likely the car is in fact in closed loop.
ok, gotcha now

Quote:
Originally Posted by BlownSS View Post
Sometimes when you buy stuff from ted, he will give you a free tune!!!!! Maybe give him a call and see what he has to get you going......kinda like buying a tune and getting a free toy!
he didn't buy it from Ted - it was one of Ted's customers

Quote:
Originally Posted by Russell James View Post
That almost sounds like the MAF isn't reading the airflow. I've worked on a few cars that knocked like crazy off idle, and they turned out to be bad MAFs. On some cars you can turn the key off, unplug the MAF, then restart the engine. And if it idles perfectly with the MAF unplugged, something is wrong with the MAF or wiring. The ECM will use a default value if the MAF is unplugged. I've never tried that on a Camaro, but it has worked on every other car I've suspected a bad MAF.

The arrow on the MAF is pointing toward the engine? It can go in backwards.
is the MAF in a different location than stock with the Fastlane? that could also be throwing off the canned Maggie tune

Quote:
Originally Posted by Russell James View Post
Seems though - if the actuator was opened, stock injectors, and OE tune it should idle normally if nothing else was wrong.
actuator is now tied open, using the bigger injectors, and the OE tune wouldn't be that great with that huge intake & catless LTs

Quote:
Originally Posted by camaro1 View Post
have you even invested in a scan tool yet,, pick one up at your local parts store,, at least one that has live data,, it will at least give you the basics of what is going on

look at your LTFT and STFT (long and short term fuel trims) and see what they are doing,, this will tell you alot!!

what did you use to extend your map sensor harness to the rear of the supercharger intake, did you use your original map sensor from your intake manifold or was there a map already installed on the supercharger, and is it also reading correct on the scan tool. and is the small vacuum port plugged on the back of the supercharger by the map sensor
the SCT acts as a scan tool, if i remember right
the boost gauge port is plugged for now
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