Engine dies at stop w/ AC on

[Hebrews2-1]

What's up guys!
Having a little problem with my engine dying ONLY when I come to a stop WITH the AC on.

The RPMs will drop tremendously low id say around 100-200 then bounce back up and down until the whole car shakes and the engine dies. I then have to sit there for a sec, turn off the AC compressor then fire her back up.

Not really sure if my specs matter but here they are anyway:

S14 SR
HKS actuator @ 11.5psi
FMIC w/ HKS bov (non recirc)
HKS air filter
3" Down pipe / 3" exhaust piping


Any help would be greatly appreciated.

[bodyboarder050]

recirculating your bov may help.I have the same problem on my car when i'm running a/c.
also check your IACV screw and make adjustments if necessary.

[Hebrews2-1]

recirculating your bov may help.I have the same problem on my car when i'm running a/c.
also check your IACV screw and make adjustments if necessary.

I figured someone would say to recirc my show off valve! :-/
I've actually never messed with my IACV before and kind of afraid of messin something up haha!

I was leaning more towards the IACV tho. I know my car has a hard time sometimes just starting up in the morning. RPM's drop low and bounce back up constantly when cold starting it. Haven't really had that problem too much since its the summer but in the winter its BAD!

[iLagX]

What is the normal Idle RPM?
IF its good then it should be your vacuum lines.

[Teddy]

Your belt could be too tight.

[Hebrews2-1]

What is the normal Idle RPM?
IF its good then it should be your vacuum lines.

Id say around 700-800

[fliprayzin240sx]

Does your idle stay where its at when you turn the AC on? The IACV might not be compensating for the extra load of the AC compressor turning on. There is a valve on there thats supposed to open up and bump the idle a bit when the AC is on and he PS is maxed all the way.

Also, you can always just bump the idle higher if the IACV isnt doing its job. I usually bump my idle up an extra 300 rpm during the summer since I know the AC will be on all the time.

[Hebrews2-1]

Your belt could be too tight.

I didn't know that could have anything to do with it. I don believe that's the issue since I just had my belts replaced and I doubt the shop put them on exactly or equally as tight as previously.



Does your idle stay where its at when you turn the AC on? The IACV might not be compensating for the extra load of the AC compressor turning on. There is a valve on there thats supposed to open up and bump the idle a bit when the AC is on and he PS is maxed all the way.

Also, you can always just bump the idle higher if the IACV isnt doing its job. I usually bump my idle up an extra 300 rpm during the summer since I know the AC will be on all the time.




Does your idle stay where its at when you turn the AC on? The IACV might not be compensating for the extra load of the AC compressor turning on. There is a valve on there thats supposed to open up and bump the idle a bit when the AC is on and he PS is maxed all the way.

Also, you can always just bump the idle higher if the IACV isnt doing its job. I usually bump my idle up an extra 300 rpm during the summer since I know the AC will be on all the time.

I'm actually not sure if the idle stays the same when i turn the AC on. Is it supposed to bump up when engaged? I'll def check it out tho.

[fliprayzin240sx]

Well the IACV is supposed to pop a valve open to keep the idle roughly the same point when the the AC is on/off. If the idle goes down by 300 rpm, then the valve isnt opening and making up for the extra load on the engine.

[s14_sr20_silvia]

Could this also be an electrical problem? I have this same issue, but I was going to try upgrading to a quest alternator and a better battery... I notice it usually when the A/C is on as well, but also when my electric fans are running it is much worse.

[Hebrews2-1]

Well the IACV is supposed to pop a valve open to keep the idle roughly the same point when the the AC is on/off. If the idle goes down by 300 rpm, then the valve isnt opening and making up for the extra load on the engine.

Just checked today and id say my car idles at around 800RPM without the AC on. As soon as i turn the AC on the RPM's drop about 250-300 RPM's, so i guess the IACV isnt doing it's job!

fliprayzin240sx do you have your Idle at like 1,100RPM's?

[fliprayzin240sx]

I got big ass cams so mine fluctuates between 900-1300. If I were you, I'd bump the idle up, then turn your AC on. I'd adjust your idle with the AC on to 800. Just leave the AC on the whole summer since its hot as shit.