Quote:
Originally Posted by scottfab
Sure sounds like it's OPEN LOOP related so yah I agree with others, fuel related. With the popping it sounds rich when in open loop. Maybe a nasty sticking open injector. Could be very time consuming to isolate. If you have a way to, find out what block/trim looks like on both sides.
Also comes to mind is the O2 sensor heater. It is suppose to bring the sensor up to temp fast. If the element is blown then it'll be slow to respond until the exhaust heats it up. Just some ideas, food for thought
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Here's your post. And I am doing this not to be argumentative but rather instructive.
If it is O/L as you point to here, then the O2 has nothing to do with it. Whatever the fueling issue is dependent on the base VE table(s). In O/L, the O2 isn't causing the ECM to modify the fueling. Having spoken to Lee about it, it appears to happen in cooler weather and before the motor is up to temp. It doesn't go into C/L until about 75C CTS. I know that since its my calibration he's using. And because he's using a copy of my cal, I also know that it's likely a bit lean since his motor has both larger intake and exhaust cams while my cal is for a larger intake cam only. There are modifier tables for the AE pumpshot and one of them deals w CTS, another w MAT, and yet another on Delta TPS%. These modify the calc'd PW in the corresponding VE table cell his motor happens to be in. If the VE is lean, the AE shot will likely also unless adjusted. That's why it's so important to get the driveability right. It's the base of the tune. Everything else revolves around it. And I know Lee's car has not been tuned properly for driveability. Given the specific conditions of Lee's problem, I suspect the cal needs to be tweaked. To me this seems to explain what is being observed in a manner much simpler than a flaky O2 sensor. Especially if its happening in O/L.