Hello,
Not entirely sure if this is where I should be posting but, I recently put in the Holley Terminator X Foxbody kit along with a Holley dual sync distributor in my 88' Turbo Foxbody. Everything has been running great so far but the idle. With closed loop, IAC and spark adjustment the car idles okay cold and warm, but at startup it surges badly and every once in it will jump about 200rpms then settle back down. In open loop with no IAC or spark adjustment, the idle is very bad, usually from 600-1300rpms. The setup is a TFS Stage 1 cam, tfs sb intake with 75mm throttle body, 61mm turbo, Ford Racing Z heads and 9:1 compression and my target idle has been low 800's(which I should be able to hit with the current setup?) however even when aiming for 1000rpm idle, the issues stay.
I'm pretty new to tuning but I think I've been doing okay up until trying to get this car to idle where I want it to.
So far I have:
-Set the IAC to Ford PWM at 315 frequency in Holley software
-Set the idle screw in a variety of positions from completely closed to 1000rpm with no IAC
-Completely cleaned the throttle body and IAC
-Messed around with the Startup and IAC ramp down settings a lot, (I tried the Fixbody videos settings as well)
-Tried to create my own 1D IAC table(based off the Fixbody video)
-Tried idle timings ranging from 10-22 degrees
-Targeted AFR's from 13.5-14.5
-Slightly lowered Startup enrichment
I have some photos of the current and my best tune so far(idle timing has not been smoothed yet), I can also send the file to anyone who wants to take a look at it. Any help would be greatly appreciated, thank you guys!

Not entirely sure if this is where I should be posting but, I recently put in the Holley Terminator X Foxbody kit along with a Holley dual sync distributor in my 88' Turbo Foxbody. Everything has been running great so far but the idle. With closed loop, IAC and spark adjustment the car idles okay cold and warm, but at startup it surges badly and every once in it will jump about 200rpms then settle back down. In open loop with no IAC or spark adjustment, the idle is very bad, usually from 600-1300rpms. The setup is a TFS Stage 1 cam, tfs sb intake with 75mm throttle body, 61mm turbo, Ford Racing Z heads and 9:1 compression and my target idle has been low 800's(which I should be able to hit with the current setup?) however even when aiming for 1000rpm idle, the issues stay.
I'm pretty new to tuning but I think I've been doing okay up until trying to get this car to idle where I want it to.
So far I have:
-Set the IAC to Ford PWM at 315 frequency in Holley software
-Set the idle screw in a variety of positions from completely closed to 1000rpm with no IAC
-Completely cleaned the throttle body and IAC
-Messed around with the Startup and IAC ramp down settings a lot, (I tried the Fixbody videos settings as well)
-Tried to create my own 1D IAC table(based off the Fixbody video)
-Tried idle timings ranging from 10-22 degrees
-Targeted AFR's from 13.5-14.5
-Slightly lowered Startup enrichment
I have some photos of the current and my best tune so far(idle timing has not been smoothed yet), I can also send the file to anyone who wants to take a look at it. Any help would be greatly appreciated, thank you guys!





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