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I need help my 98 mustang gt idles fine on start up but when I cut the ac compressor on and drive for a while car will cut off when coming to a stop? Does the IAC need cleaning would that cause it to stall with ac on? And is there a reset you have to do afterwards? Thanks
Not sure if this will help you or not, but I had problems with my 2001 GT a few years back such as idle running too high when A/C was on and then stalling when the A/C would cycle off at idle...or sometimes simply stalling when letting off the throttle...in short it would rarely settle to a normal idle. In the process I found other vacuum plumbing issues that weren't helping my problem, but rectifying all that didn't take care of my idle/stall problems...it made them more consistent, but I still had problems, and ultimately what fixed my issue was replacing the IACV. I tried removing my original IACV and cleaning with carb cleaner, tried testing it by applying power with a bench power supply to verify proper operation but my tests were inconclusive and rather than wondering or persisting with the dickering I spent $50 at my LAPS and got a new IACV. *Boom*...instant rock steady idle behavior. Here is the thread...hope it helps:
There's also a resistance check for the IAC solenoid, and if the spec is anything like my 95's spec, you're looking for 6.0-13.0 ohms. (Hopefully someone around here can confirm if that is indeed the correct spec for the 4.6 IAC.)
Not sure if this will help you or not, but I had problems with my 2001 GT a few years back such as idle running too high when A/C was on and then stalling when the A/C would cycle off at idle...or sometimes simply stalling when letting off the throttle...in short it would rarely settle to a normal idle. In the process I found other vacuum plumbing issues that weren't helping my problem, but rectifying all that didn't take care of my idle/stall problems...it made them more consistent, but I still had problems, and ultimately what fixed my issue was replacing the IACV. I tried removing my original IACV and cleaning with carb cleaner, tried testing it by applying power with a bench power supply to verify proper operation but my tests were inconclusive and rather than wondering or persisting with the dickering I spent $50 at my LAPS and got a new IACV. *Boom*...instant rock steady idle behavior. Here is the thread...hope it helps:
Thanks! See here's the thing tho the ac compressor, clutch wouldn't cut on or engage so I ran a toggle switch and hot wired it basically. But when I'd cut the ac on and be driving it'd stall out coming to a stop. I was thinking the IAC. But my mechanic told me that it was probably still the ccrm and that it was supposed make it idle up. I going to probably just replace both ccrm and the iac.
There's also a resistance check for the IAC solenoid, and if the spec is anything like my 95's spec, you're looking for 6.0-13.0 ohms. (Hopefully someone around here can confirm if that is indeed the correct spec for the 4.6 IAC.)
Originally Posted by sweetbeats
Not sure if this will help you or not, but I had problems with my 2001 GT a few years back such as idle running too high when A/C was on and then stalling when the A/C would cycle off at idle...or sometimes simply stalling when letting off the throttle...in short it would rarely settle to a normal idle. In the process I found other vacuum plumbing issues that weren't helping my problem, but rectifying all that didn't take care of my idle/stall problems...it made them more consistent, but I still had problems, and ultimately what fixed my issue was replacing the IACV. I tried removing my original IACV and cleaning with carb cleaner, tried testing it by applying power with a bench power supply to verify proper operation but my tests were inconclusive and rather than wondering or persisting with the dickering I spent $50 at my LAPS and got a new IACV. *Boom*...instant rock steady idle behavior. Here is the thread...hope it helps:
Thanks! See here's the thing tho the ac compressor, clutch wouldn't cut on or engage so I ran a toggle switch and hot wired it basically. But when I'd cut the ac on and be driving it'd stall out coming to a stop. I was thinking the IAC. But my mechanic told me that it was probably still the ccrm and that it was supposed make it idle up. I know you told me that the ccrm doesn't make it idle up.. so I'm going to probably just replace both ccrm and the iac.
Here’s the issue with what you did with your A/C clutch bypass...now the CCRM doesn’t know the A/C is on when it’s on. There’s a relay that powers the A/C clutch on the CCRM board, and when it’s closed the CCRM tells the IACV to do stuff so the engine idles up to compensate for the compressor drag. I had trouble getting my A/C compressor clutch to engage. Ultimately it was a bad solder joint on the CCRM at the A/C clutch relay. I had a thread about it. I don’t know if this is your problem, but I can tell you for certain your bypass makes the CCRM blind to the A/C clutch being powered.
Here’s the issue with what you did with your A/C clutch bypass...now the CCRM doesn’t know the A/C is on when it’s on. There’s a relay that powers the A/C clutch on the CCRM board, and when it’s closed the CCRM tells the IACV to do stuff so the engine idles up to compensate for the compressor drag. I had trouble getting my A/C compressor clutch to engage. Ultimately it was a bad solder joint on the CCRM at the A/C clutch relay. I had a thread about it. I don’t know if this is your problem, but I can tell you for certain your bypass makes the CCRM blind to the A/C clutch being powered.
Nice looking Mustang. All that black looks nice and the smoke black lights will look great.
I will say the SN95 body does look good sitting lower. I don't know how much lower ours is from stock, but the muscular body style really pops when lowered I think. We have 18x8 rims on the front and 18x9 at the back.
Last edited by sweetbeats; 08-17-2018 at 07:44 PM.
08-14-2018, 11:08 AM
IAC
