startup fuel trims

hey guys,,

ive found something really weird.

when i start my car. car reads 1.0 lamda(good) then after about 5 seconds, the lambda starts dropping down to 0.80.. 10-15 seconds later STFTs kick in and bring it back to 1.0 lambda.. then as the motor gets warm, the LTFTs take over. typically they average around -13%

but get this.. i go around the block and pull back in the driveway and the ltfts are now -2.0%.... WTF

what table should i be looking at fix this?

startup airflow vs ert vs ect
or
base running airflow off?

car drives fine. not sure this is a problem. but thats for taking a look!

-Carl

bumpity bump!

Log the fuel trim cell... I bet you'll find that your trims are much farther negative when the fuel trim cell is 21 or higher.

My car does a similar thing, 2010 camaro.

After I flash the computer even if i did not make any changes tot he fueling the car will start up and the fuel trims will be way out like 10-15% where as before I flashed it they were almost 0. Then after some driving it will go back to normal.

I think part of the problem could be purge flow from the evap system throwing the fueling off.

ok.. i logged a run.. take a look

how do i tune the FTC to stop adding so much fuel..?

-carl

Quote:

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Originally Posted by carlrx7

ok.. i logged a run.. take a look

how do i tune the FTC to stop adding so much fuel..?

-carl

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I can't see the log right now, but you don't... it just means EVAP purge is dumping a ton of vapor.