High/Fluctuating Idle and Occasional Stalling

[ViciousBlack97]

High/Fluctuating Idle and Occasional Stalling After Dyno Tune

Ever since the car got dyno tuned, the idle has been higher than usual. Before, it used to be around 800 or a little less, but for the past while, it never goes below between 900 and 1000 rpm, and fluctuates in between them. Along with that, it has stalled a few times, usually when I come back into the driveway to park the car. The IAC was replaced in the past month, and all of the normal maintenance items have been taken care of other than the coils and wires. Like I said, this wasn't an issue before the tune. Is this an issue with the tune I received, or is there something else that I'm not catching?

 

[bergz22]

It could be with the tune. Are you able to reload the stock tune?

 

[ViciousBlack97]

It's on a chip in the ECU. I've been thinking about emailing the tuner and seeing how he wants to approach it.

 

[bergz22]

I would email them and see what they say. If you can go back to stock tune and the problem is gone then it is in the tune.

 

[ViciousBlack97]

The tune makes sense, because it had no problem idling before, and had never stalled. Idk how he could have tuned it wrong, the guy has tuned lots of Mustangs and Cobras before.....

 

[mwolson]

These kinds of driveability issues are not uncommon with a modified car with a tune. Your tuner should be willing and able to work with you to fix them.

 

[bergz22]

I have had lots of issues after my car got tuned. It would at random times just cut out and die when it came down to an idle. It was also idling near 900 rpm and would hang there for 25 sec or so. I have it somewhat straightened out but will be working on it again once it warms up.

 

[ViciousBlack97]

After the tune was done, he told me about how the o2s were acting up, but again, the car was fine before the tune, so idk

 

[ViciousBlack97]

I emailed the tuner, so now I'm just waiting for a reply

 

[Prototype007]

I might be time to consider buying some o2 sensors.

Check everywhere for vacuum leaks and loose electrical connections. Then after that check everything again.

It only takes the littlest thing to make these cars act all finicky!

 

[CompOrangeStang]

Id check the iac just to be safe, even if it's new. While the car is running, unplug the iac. It should sputter and stall almost immediately. If it doesn't, the iac is bad.