surging idle switching from sync to async

**mike65** · 05-01-2015

Dave,
I set the async off parameters with the correct units and now the sync/async switching at idle has stopped!

The first thing after the chip change that I noticed was after warm up the idle speed was higher at about 1050rpm so I adjust down to 550rpm with IAC at 40 and then took for test drive.

During the test drive I noticed the following:

-DFCO is now very noticeable and cuts in/out every 1/2 sec right up until I come to a complete stop. I could feel these before, but now much more predominant.

-Async kicked in once or twice while cruising at about 40mph???....but only for a very brief moment.

-After short drives, while left at idle for a couple minutes, it starts going in and out of open/close loop.

All sensor info looks good and no error codes.

Any Thoughts?

**dave w** · 05-01-2015

There are several parameters for Open / Closed loop. I use the Parameter Finder from the Tool Menu to display parameters. See attached screen shots. I think it would be a good plan, to adjust one Open / Closed loop parameter at a time to achieve the desired idle you want. That's Tuning.

dave w

**mike65** · 05-08-2015

Just wanted to leave an update......been on business travel for the past week and tonight was the first chance I've had to run the jeep. What I noticed tonight was different from before....last time it was idling up and down as it went in and out of open/close loop. Tonight it was idling up and down while in closed loop around 800rpm with 200rpm swing. One thing I noticed on the TunerPro dashboard was that it was showing "Park' all the time which seemed odd. I did some troubleshooting and discovered that the switch was bad and staying grounded all the time. Once I disconnected the wire lead the idle dropped off and the motor died. I repeated reconnect/discount several times and the same thing every time, the motor would drop off in RPM and die. I would've thought the RPM would increase as it when from park to drive. Any thoughts?.. I'll replace the switch this weekend and continue tuning.
Mike