Car almost died at idle with AC on! :(

[clumpymold]

Hey all,

I just noticed this yesterday while at a stop light and with my air conditioner on (on the lowest setting). My car's RPMs would drop to almost zero, then sputter a bit then recover. It happened twice that day. I HARDLY ever have my A/C on so not sure if this is common or not.

Anyone else have this problem? I know this happened with my old E30 as well but can it be fixed?

Thanks!

- Curtis

[Balthazarr]

At what rpm do you normally idle?

If too low this shutoff will occur.
Sometimes throttle cable stretches, so you might want to check that and take up the slack.

[clumpymold]

At what rpm do you normally idle?

If too low this shutoff will occur.
Sometimes throttle cable stretches, so you might want to check that and take up the slack.

Wow, thanks for the super fast post, Balthazarr!

I normally idle around 600-800, I believe. I know it's under 1k though and more than 500 (or that first tick mark). It's never happened before but I saw it sputter and ALMOST die then it recovered. Odd.

What's "normal" idle rpms? On startup?

[Mpowered02]

You might also wanna check your ICV (Idle Control Valve). The job of the ICV is to vary the idle speed diepending on the needs. For example, it is responsible for increasing the idle slightly when you turn on the AC to prevent stalling.

When I first installed the M50 manifold on my car I inadvertently pinched one of the hoses going to the ICV so it wasn't supplying air to the engine to raise the idle and I was having the same problem (low idle and stalling when I turned on the AC). Once I unpinched the hose all was good. In your case, maybe the ICV is just dirty and needs a good cleaning.

I'd try cleaning the ICV first. Hope this helps...

[clumpymold]

You might also wanna check your ICV (Idle Control Valve). The job of the ICV is to vary the idle speed diepending on the needs. For example, it is responsible for increasing the idle slightly when you turn on the AC to prevent stalling.

When I first installed the M50 manifold on my car I inadvertently pinched one of the hoses going to the ICV so it wasn't supplying air to the engine to raise the idle and I was having the same problem (low idle and stalling when I turned on the AC). Once I unpinched the hose all was good. In your case, maybe the ICV is just dirty and needs a good cleaning.

I'd try cleaning the ICV first. Hope this helps...

Alright, will do. I did read up on that but I didn't know that regulated the idle when the AC was turned on as well.

What is the normal idle rpms? What about during startup and when the AC is on? Does it matter how high the AC is on?

[Balthazarr]

mine idles religiously at 725 -750 rpm.
I do get a little surge when putting in neutral while braking,but very slight.
And only occasionally.

[Hit_Apex]

mine idles religiously at 725 -750 rpm.
I do get a little surge when putting in neutral while braking,but very slight.
And only occasionally.

No dip when A/C kicks on? I think a dip is normal when A/C compressor cycles - the ICV can only react so fast. The fact that your car didn't die tells me the ICV is doing its job. I get little dips and surges all the time with A/C on - never thought twice about it.

[Balthazarr]

Don't use AC as a rule. Just once in a while to make sure it works, say once a month.
Sunroof and fan do all the cooling I need in the cabin.

When I do use it, I hate the way my car reacts to it.

[clumpymold]

No dip when A/C kicks on? I think a dip is normal when A/C compressor cycles - the ICV can only react so fast. The fact that your car didn't die tells me the ICV is doing its job. I get little dips and surges all the time with A/C on - never thought twice about it.

Yeah, that's what I thought. But it went REALLY low. Almost to zero. Sputtered a little, then came back to normal. Was just a bit worried about it dying someday.

Maybe I'll try to clean my ICV soon.

Balthazarr: Yeah, I don't use AC that often. Like I said, I've had this car for almost 7 months now and this was pretty much one of the few times I've used it. First time I've noticed this as well. I just had it on because I had a passenger. Normally I would just roll the window down a tad and open the sunroof. I have DARK windows so rolling them down keeps the cops at bay.

[@bgynite@]

did you fix it ihave same problem

[clumpymold]

did you fix it ihave same problem

Wow, super old thread. Honestly, I don't remember. I just know it's not an issue anymore. Probably because I hardly drive my car anymore (I have my bike now).

[ssj4]

mine started doing that at about 125k, then the AC (or was it the recirc) light started going off unexpectedly. It was teh AC compressor going bad