What idle rpm for a 2001 ford mustang GT

[Adam Vinnicombe]

Hi all I'm back. Right on my 2001 ford mustang GT I have a diablosport tune and ever since I brought it the idle rpm had been at 1000rpm and if I ever tried to lower it the engine rpm would bonce around all over the place and eventually stall. Any way I've since changed the idle control valve and both front O2 sensors that stopped working and now at last I can set the idle rpm to what ever I want. But what should the idle rpm be?
I can set it to as low as 540rpm (any lower and she does not sound happy) up to what ever I want but what should it be set to.
Also what are the disadvantages or problems with settle the idle to low?
Many thanks Adam.

 

[Silver95bird]

i think around 7-800 isn't bad, but keep in mind its always higher if the A/C compressor is running.

my old Tbird would idle as low as 3-400 and not die out. sounded like it had a cam in it though that low. cleaned the iac and it was fine after that.

Sent from my moto z3 using Tapatalk

 

[RAU03MACH]

800 to 870 safe for accessories or every stop it dies

 

[07GtS197]

I believe stock is around 800 rpms. Have you touched the throttle body stop screw?


Sent from my iPhone using Tapatalk

 

[Adam Vinnicombe]

No I've not touched the throttle body screw I've just lowered the idle with the diabolospot I1000 tuner.
OK so you lot are saying 650rpm idle is to low and shoot for 800rpm

 

[01yellercobra]

I think the stock idle on my son's 98 was like 570rpm in gear. My Cobra is under 700rpm stock. I have it at 800 though. If it's stock I'd put it around 650.

 

[07GtS197]

It depends on whats done to the car and whether you have underdrive pullies or not. But you should figure out why it wont idle lower than 1k rpms. Theres no codes? Do you have means to datalog?


Sent from my iPhone using Tapatalk

 

[Adam Vinnicombe]

It wouldn't idle be low 1000 rpm the IACV was playing up plus bith the front O2 sensors were both giving a false lean reading which was causing the LTFT and STFT to go max rich and the wide band innovate I have was pegged rich and the engine would just stall if the idle rpm got below 1000 rpm.
As soon as I replaced the O2 sensors the LTFT and STFT fell back to zero and the engine engine began to idle lower, smoother, quiter.

Yes I do have a means to datalog, whys that?

I can't remember the fault codes now but I think they were P0133, P0153, P0401, there was more but I can't remember them now. I was getting lean codes then rich fault codes all the time and O2 sensors slow to respond