My car runs alot better warming up. It idles fine, and it pulls really good. But once it warms up, the power goes away. Is there different timing retard during warm up? Any explanations?

cooler engine=cooler air. plus, you probably get used to the power after a few pulls. my eclipse used to bog like shit on hot days after a few minutes of warming up. during the "winter" (we really dont have those this far south) it felt much more consistant.

o2 sensor.

closed loop vs open loop.

Originally posted by thedawg
o2 sensor. closed loop vs open loop.

But wouldnt the car be in open loop during warm up anyways? And I dont get a cel for a O2 sensor.

The car will run pretty rich at warm up trying to warm itself up more quickly. You may have a problem with the coolant temp sensor or something. :shrug

Originally posted by Blizare
The car will run pretty rich at warm up trying to warm itself up more quickly. You may have a problem with the coolant temp sensor or something. :shrug

Bingo, warmup enrichment. Is your car running leaner than it should be once it's warmed up? If your fuel system is a bit lean it might happen to be just right during warmup but after that the stock ECU will pull that extra fuel out causing an issue.