Today when I turned my AC on the rpms dropped drastically and the car stalled. It starts up fine and idles perfectly without the AC running. Another problem I noticed is that when I push in the clutch while driving or put the car in neutral when slowing down for a stop light, the rpms pause at 1500 and then slowly drop down to the normal 700-800 rpms. I would really appreciate any help or suggestions you guys can give me.
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Rough Idle with AC on
- Thread starter Redcallen
- Start date
Thanks for the quick replybad motor mount.
Could it be anything else?
That is true about the rpm but mine used to drop pretty low when i turned on my a/c. With my new motor mount it seems alot better. The stocker was ripped apart.
Air filter could be a problem as well as the spark plugs, however if those were what cause the problem why would it only be when i starts the a/c.
Maybe it is the alternator because of the increased load that is being put on the motor it is causing it to stumble and stall cause there just isn't enough juice to power the beast.
Air filter could be a problem as well as the spark plugs, however if those were what cause the problem why would it only be when i starts the a/c.
Maybe it is the alternator because of the increased load that is being put on the motor it is causing it to stumble and stall cause there just isn't enough juice to power the beast.
A motor mount DOES NOT have anything to do with RPM levels.
The MM will effect cabin vibrations when you turn on your AC (I speak from experience on this one) -- but that's about the extent that the one has on the other.
Anyway, in regards to the OP's idle .. it'll help us if you let us know what engine mods you have done, other than the Injen CAI you already stated.
The Protege is a little quirkly as far as RPMs are concerned until the engine is fully warmed up. Also, you might want to try cleaning out your EGR valve -- that's notorious for causing spazzy idle.
I'm wondering if there might be some kind of vacuum leak, though. Turning on your AC not only increases the load, but it also changes the pressure of your system. Check around your bay for any kinda leaks.
The MM will effect cabin vibrations when you turn on your AC (I speak from experience on this one) -- but that's about the extent that the one has on the other.
Anyway, in regards to the OP's idle .. it'll help us if you let us know what engine mods you have done, other than the Injen CAI you already stated.
The Protege is a little quirkly as far as RPMs are concerned until the engine is fully warmed up. Also, you might want to try cleaning out your EGR valve -- that's notorious for causing spazzy idle.
I'm wondering if there might be some kind of vacuum leak, though. Turning on your AC not only increases the load, but it also changes the pressure of your system. Check around your bay for any kinda leaks.
the other engine related mods I have done to the car are SLS catless J-midpipe, and Fuel cut defenserA motor mount DOES NOT have anything to do with RPM levels.
The MM will effect cabin vibrations when you turn on your AC (I speak from experience on this one) -- but that's about the extent that the one has on the other.
Anyway, in regards to the OP's idle .. it'll help us if you let us know what engine mods you have done, other than the Injen CAI you already stated.
The Protege is a little quirkly as far as RPMs are concerned until the engine is fully warmed up. Also, you might want to try cleaning out your EGR valve -- that's notorious for causing spazzy idle.
I'm wondering if there might be some kind of vacuum leak, though. Turning on your AC not only increases the load, but it also changes the pressure of your system. Check around your bay for any kinda leaks.
A few questions for you:
Vac reading at idle?
How many miles on the car?
Do you have access to a voltmeter or load tester?
Has the issue duplicated itself since your initial post?
Curious as to why an FCD on a basically stock set up?
My vac at idle is about 21 in.Hg
97500 miles on the car.
I can probably get ahold of a tester.
It hasn't done it again since I posted,
and I have an FCD because I was running 10psi for awhile, and getting fuel cut.
BlackCherry06
Member
- :
- '17 CX-3 GT
The high idle while the car is moving is common and most cars are actually programmed to do that.
The dying with A/C suggests to me that it's the idle air control valve. I've had a couple of Civics, a Cougar and an Explorer come down with that. When they go bad, they can be erratic...sometimes working, sometimes not. Basically they're responsible for high idle during warm up and idling-up when you turn on the A/C to offset the extra load.
The dying with A/C suggests to me that it's the idle air control valve. I've had a couple of Civics, a Cougar and an Explorer come down with that. When they go bad, they can be erratic...sometimes working, sometimes not. Basically they're responsible for high idle during warm up and idling-up when you turn on the A/C to offset the extra load.
The high idle while the car is moving is common and most cars are actually programmed to do that.
The dying with A/C suggests to me that it's the idle air control valve. I've had a couple of Civics, a Cougar and an Explorer come down with that. When they go bad, they can be erratic...sometimes working, sometimes not. Basically they're responsible for high idle during warm up and idling-up when you turn on the A/C to offset the extra load.
Thanks that makes sense.
Do you know where it's located?
My car does that too
My car seems to be doing that also. Especially when the car isn't warmed up as much. Rush, you mentioned something to this effect; is it just because the car isn't warmed up all the way?? My car just started doing that this morning, and never did that before. It has about 57500 miles on it and my mods are listed in my signature. What do you think, guys/gals??
My car seems to be doing that also. Especially when the car isn't warmed up as much. Rush, you mentioned something to this effect; is it just because the car isn't warmed up all the way?? My car just started doing that this morning, and never did that before. It has about 57500 miles on it and my mods are listed in my signature. What do you think, guys/gals??
siberiankiss
Member
- :
- blazing yellow MSP #1622
i've been having a similar issue... i've always had a little bit of a problem with an erratic/low idle, but it's starting to be more prominent when my a/c is turned on. I have to leave my a/c off if i'm stuck in stop and go traffic, or at a light because when the compressor turns off the rpms fall so low i know the car would die if i weren't to give it some throttle. if the a/c is not on it idls perfectly fine...
also, another a/c related issue... the a/c cools fine as long as the engine is under load, but as soon as i stop it gets warm very quickly. i still have not checked the freon or anything, but just wondering if anyone has a quick suggestion of other things to fix..?
also, another a/c related issue... the a/c cools fine as long as the engine is under load, but as soon as i stop it gets warm very quickly. i still have not checked the freon or anything, but just wondering if anyone has a quick suggestion of other things to fix..?
shane02pro5
25ish_psi
- :
- New Caney TX
First thing look for vac leaks (spray carb cleaner around vac lines near the intake mani) and maybe cleaning the egr valve...and I haven't seen any cases of bad IAC sensors.
Beyond that on top of the throttle body there is a recessed phillips/flathead screw (not allen head this is the idle screw and will cause problems). Try backing this screw out about 1-2 full 360 turn or maybe a bit more...this is a bleed valve and allows a bit of air to bypass the throttle plate at idle. When there is a surge in the elec system it won't bog the motor as badly. If you back it out too much you will start to hear a vac leak so tighten it back until its gone. This worked for me and I'm at 21vac at idle and when the a/c kicks in I'm around 17vac. I'm running a Haltech and had to add a bit of fuel at idle also but the stock ecu should be able to account for this. Just note the position of the screw and if it doesn't help you can set it back to where it was.
Also my a/c is doing the same sitting in traffic. Our a/c systems are very sensitive and you can't just add some r34...the system has to be vacuumed and filled at the same time to keep just the right pressure to work properly. I added a can a couple years ago and it was cold for a week and then back to barely cool so I took it in and had it leak tested evac'ed and refilled. They only had to add another 3oz or so.
Beyond that on top of the throttle body there is a recessed phillips/flathead screw (not allen head this is the idle screw and will cause problems). Try backing this screw out about 1-2 full 360 turn or maybe a bit more...this is a bleed valve and allows a bit of air to bypass the throttle plate at idle. When there is a surge in the elec system it won't bog the motor as badly. If you back it out too much you will start to hear a vac leak so tighten it back until its gone. This worked for me and I'm at 21vac at idle and when the a/c kicks in I'm around 17vac. I'm running a Haltech and had to add a bit of fuel at idle also but the stock ecu should be able to account for this. Just note the position of the screw and if it doesn't help you can set it back to where it was.
Also my a/c is doing the same sitting in traffic. Our a/c systems are very sensitive and you can't just add some r34...the system has to be vacuumed and filled at the same time to keep just the right pressure to work properly. I added a can a couple years ago and it was cold for a week and then back to barely cool so I took it in and had it leak tested evac'ed and refilled. They only had to add another 3oz or so.
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Did you get this resolved? I've got an idle problem that's killing me: http://www.mazdas247.com/forum/showthread.php?123855161-Yet-ANOTHER-rough-idle-2002-P5
