2018 Mustang GT Vortech - Idle Surge

[WesDuenkel]

I'm having a devil of a time taming the idle with my 2018 Mustang GT with a Vortech kit. Car runs very well, except I have a surging idle that I can't seem to make a dent in solving.

Car wil idle fine for about 1 minute, but as it appoaches the target idle speed, it starts surging and gets close to stalling (it's stalled once). I've tried refining the MAF curve (helped somewhat), but adjusting the idle speed and general idle settings haven't made a difference. I also tried reclocking the MAF to see if that solved it, but no luck.

Attached is a log and the tune file from which the log was created.

Any insight help is greatly appreciated!

2018 Mustang GT Wes 029 Idle RPM.hpt

Idle Surge 2.hpl

[veeefour]

Your problem is related to spark, brdl tables set up incorrectly, funny way to say the least.

[WesDuenkel]

Your problem is related to spark, brdl tables set up incorrectly, funny way to say the least.

Thanks for the tip. It seems like the easy fix is to adjust the scaling down low so that the last breakpoint is 0.25 load rather than 0.10 load so the spark isn't jumping around as load changes between those two points. At least I'm going to try that first.

[veeefour]

Good thinking, since you retain IMRC and MP associated there with you might want to start with stock values for low load optimal stability

[WesDuenkel]

Good thinking, since you retain IMRC and MP associated there with you might want to start with stock values for low load optimal stability

No success, and no real change in behavior. Something I've observed:

1) Even though the idle speed is 690 RPM, it never gets there. It surges between around 740 RPM.

2) The ignition timing is very low. Like in the single digits. I know it moves around, but taking into account #1 above, it's like it's pulling timing to hit the idle target, but can never get ther because something is "pushing back."

3) I tried entering the OEM Borderline spark settings for MP 0 and MP 1, but the results were the same. Still surges.

I'm pretty baffled here. I think the reason it can't hit the target idle speed is related to why it's surging.

23-08-02 22-26-38.hpl

2018 Mustang GT Wes 029 Vortech Spark Borderline 0 and 1.hpt

[Thatwhite5.0]

Change ETC PR Filtering to stock. Table 9454 in ETC Tab.

What injectors are you running?

[WesDuenkel]

Change ETC PR Filtering to stock. Table 9454 in ETC Tab.

What injectors are you running?

I'll give that a try.

Vortech says "47LB EV14" injectors. I was hoping for a brand/model etc, as I understand injector data is critical for these cars. Here is a photo (albeit very zoomed in) of the injectors:

Screen Shot 2023-08-03 at 4.07.11 PM.jpg

Upon edit: they appear to be M-9593-G302 injectors. The data in HpTuners also seems to be consistent with that.