Engine stumbles when returning to idle speed

Ryan · 07-27-2004, 09:48 PM

I have an 01 S2k and it does something strange when the A/C is on. I can rev the car up to any rpm over about 3k and then put the clutch in and let off the gas. The engine will drop way below idle speed, down to about 400rpm (hard to tell with digital tac). The engine will stumble like it is going to stall and then return to standard idle speed. It's very annoying! Has anyone else seen this problem and how was it fixed?

I asked the dealership, they said it was too much pressure in the A/C lines, claimed to have released some of this "pressure" and told me it was fixed, but the problem is still there.

gqwhit27 · 07-28-2004, 05:15 PM

i have an 01 and have the same annoying problem, would also be interested if anyone has an answer

ExoSpeed · 07-29-2004, 02:57 PM

I have a 00 S2K and live in AZ. I have the exact same problem and am still covered under honda care. I spoke to 3 differnt dealers and they all say this is normal for even the 04's. I very much dislike the sound but, they say it normal... I'm curious as to any info on this too.

ExoSpeed · 08-02-2004, 09:26 AM

I would like it if anyone had any real info on this .... come on guys.

ExoSpeed · 08-18-2004, 12:47 PM

Bump... Any answers out there?

gstate · 08-18-2004, 04:17 PM

anyone have a problem with the car kind of shaking at idle with the a/c on. ('01 s2k)

ExoSpeed · 08-19-2004, 09:17 AM

Ya, that is what my car does just as posted above. I have found a work around kinda. It seems to happen less often if I leave my a/c off for a short time and then turn it on after I've been running for about 3-5 min. I'm not a 100% sure it's really a fix but, seems that the computer needs some time. My concern is that it caused some damage to my motor. If anyone can tell us if this IS normal as the dealer stated that would be grand. TY

I'm in Arizona so, a/c is a must most of the time.

energetic · 08-25-2004, 03:09 AM

I have a similar problem but with the A/C off. If am on stop and my gear is on neutral the rpm's are around 950-1000. When I step on the throttle, just a little, up to 1500rpm and then release it, the rpm's goes to 800 and can hear the engine that is going to turn off, but instead the rpm's going back to 950-1000. I though may be an adjustment was needed but when am on a still the rpm's are stable.

gstate · 08-25-2004, 06:54 AM

Well, I recently had the same problem with my '01
and had it checked out. Come to find out the injector in cylinder 2 was
bad and had to be replaced, so i suggest that you get it looked at.

liemha · 04-26-2008, 10:41 PM

same problem here, anyone found an answer yet?

desmo4 · 04-26-2008, 11:51 PM

I have heard of this before at S2kCA and it has to do with the ECU learning for a slightly different conditions. The solution is to drive it normally and if the engine speed slows down, go not touch the throttle or try to prevent it from slowing or stalling. This will allow the ECU to adjust it's map. If it repeatedly stalls then your problem is deeper and you will probably be getting a cel at this point, to be investigated.

Jonathan

SXY_S2K · 04-26-2008, 11:55 PM

Yeah, I'm in AZ, and from what I've heard, all the tech's say to start it without AC on, idle to running temp, and then it's ok for AC. I always shut my AC off at least 30 secs before shutting her off too, just til idle is smooth...

philiam · 04-27-2008, 12:41 AM

Quote:

Originally Posted by ExoSpeed

I have a 00 S2K and live in AZ. I have the exact same problem and am still covered under honda care. I spoke to 3 differnt dealers and they all say this is normal for even the 04's. I very much dislike the sound but, they say it normal... I'm curious as to any info on this too.

My 02 doesn't do that.

SilverS2K422 · 04-27-2008, 02:49 AM

my 02 does that too, my buddy said it might be the engine droppin back to idle, like slows down alot and drop below what its spos to be and catches itself hard to explain

SilverS2K422 · 04-27-2008, 02:50 AM

it sounded better comin out oh his mouth. lol

SXY_S2K · 04-27-2008, 02:51 AM

It's just the ECU learning the different situations it's in...

jagg · 04-27-2008, 07:23 AM

It sounds like the idle is just adjusting to the extra load created by running the a/c compressor..As long as it doesn't stall, I wouldn't think it's indicative of a problem.

jagg

Ualreadykno · 04-27-2008, 09:17 AM

Quote:

Originally Posted by SXY_S2K

It's just the ECU learning the different situations it's in...

Well I have a '00 and have never had a problem with this. Maybe mine has learned its situations already. Maybe I need to go knock on wood too!

dezignpro04 · 04-27-2008, 09:32 AM

Quote:

Originally Posted by Ualreadykno

Well I have a '00 and have never had a problem with this. Maybe mine has learned its situations already. Maybe I need to go knock on wood too!

I knocked for ya.. lol

Mine does this sometimes, but it is because I have a cold air intake. When your ECU is adjusting for the "extra" air it is receiving it will do that little sputter sometimes. Sometimes this will help:

1. Make sure engine is off
2. Unplug all IAC/MAP sensors (should be three around the intake manifold)
3. Plug them back in and turn on the engine.

IF it still sputters you can do the above with the engine on and it will sound like the engine is going to die. Plug the sensors back in and the ECU will start adjusting. It kinda resets the ECU and makes it start over. Hope it helps..

Mike

Ualreadykno · 04-27-2008, 09:39 AM

Quote:

Originally Posted by dezignpro04

I knocked for ya.. lol

Mine does this sometimes, but it is because I have a cold air intake. When your ECU is adjusting for the "extra" air it is receiving it will do that little sputter sometimes. Sometimes this will help:

1. Make sure engine is off
2. Unplug all IAC/MAP sensors (should be three around the intake manifold)
3. Plug them back in and turn on the engine.

IF it still sputters you can do the above with the engine on and it will sound like the engine is going to die. Plug the sensors back in and the ECU will start adjusting. It kinda resets the ECU and makes it start over. Hope it helps..

Mike

How much added HP with the cold air intake and how much was it? Thnx

J'sS2K · 04-27-2008, 09:45 AM

Let it warm up to 5 bars. It does that when it's not fully warmed up.

DJJSR · 04-27-2008, 09:51 AM

Quote:

Originally Posted by dezignpro04

Mine does this sometimes, but it is because I have a cold air intake. When your ECU is adjusting for the "extra" air it is receiving it will do that little sputter sometimes.

I don't understand how a cold air intake allows more air at idle. The 2.0 liter engine requires only 35 cfm of air at 1000 RPMs. The 2.4 liter engine requires only 42 cfm at 1000 rpm. The stock air intake can flow over 300 cfm. Can you explain?

sky2k · 04-27-2008, 02:46 PM

i have the same problem on my 01...when i first started it when i bought it, the ac was on and it did that dip to low rpms as if it were going to stall out...but its only when the ac is on for me...being a fellow desert dweller, it does get annoying, i drive the car for about a minute or two before the ac goes on, it still does it but not as bad i guess...seems normal though...i've talked to mechanics and have heard the same "fixes" mentioned above...

dezignpro04 · 04-27-2008, 03:14 PM

Quote:

Originally Posted by DJJSR

I don't understand how a cold air intake allows more air at idle. The 2.0 liter engine requires only 35 cfm of air at 1000 RPMs. The 2.4 liter engine requires only 42 cfm at 1000 rpm. The stock air intake can flow over 300 cfm. Can you explain?

Let me explain. Take (2) straws. One of those big gulp straws from circle k and a coffee stirir straw. If you try and use that straw to drink some dr pepper it will take quite a bit of effort to suck in lets say 3 ounces. Now use the same effort but with the big gulp straw. With that same effort you may get 6 ounces. So you have to adjust the the strength of your "sucking" accordingly.

Works the same for a cold air intake. When useing the stock intake at 800 rpm, it is pulling in lets say 33cfm. Now with a CAI at 800rpm you can be pulling 47cfm. Now that you have more air you will need more gas in the cylinders or you will run lean. The ECU takes care of that. So when your engine is cold and optimum ingition isnt happining, you could acheive the "sputter" we are speaking of....

Hope that helps!!

dezignpro04 · 04-27-2008, 03:16 PM

Quote:

Originally Posted by Ualreadykno

How much added HP with the cold air intake and how much was it? Thnx

AEM CAI will run you anywhere from $240 - $300 depending where you get it. It claims 6hp, but I have no dyno tests to prove that!

DJJSR · 04-27-2008, 04:11 PM

Quote:

Originally Posted by dezignpro04

Works the same for a cold air intake. When useing the stock intake at 800 rpm, it is pulling in lets say 33cfm. Now with a CAI at 800rpm you can be pulling 47cfm. Now that you have more air you will need more gas in the cylinders or you will run lean. The ECU takes care of that. So when your engine is cold and optimum ingition isnt happining, you could acheive the "sputter" we are speaking of....

Hope that helps!!

A 2.4 liter engine turning 800 rpm pulls in 33 cfm at 100% volumetric efficiency. In order for it to pull in 47 cfm it would have to be supercharged or turbocharged because the volumetric efficiency would be 140%. Neither a stock intake or a cold air intake is restrictive at low rpms. So the engine that needs 33 cfm will pull 33 cfm regardless of the intake.

philiam · 04-27-2008, 04:22 PM

Quote:

Originally Posted by J'sS2K

Let it warm up to 5 bars. It does that when it's not fully warmed up.

Mine never goes over 3 bars.

07-27-2004, 09:48 PM	#1 (permalink)
Ryan Junior Member Join Date: Jul 2004 Posts: 1	Engine stumbles when returning to idle speed I have an 01 S2k and it does something strange when the A/C is on. I can rev the car up to any rpm over about 3k and then put the clutch in and let off the gas. The engine will drop way below idle speed, down to about 400rpm (hard to tell with digital tac). The engine will stumble like it is going to stall and then return to standard idle speed. It's very annoying! Has anyone else seen this problem and how was it fixed? I asked the dealership, they said it was too much pressure in the A/C lines, claimed to have released some of this "pressure" and told me it was fixed, but the problem is still there.

04-26-2008, 11:51 PM	#11 (permalink)
desmo4 Senior Member Join Date: Oct 2007 Posts: 543	I have heard of this before at S2kCA and it has to do with the ECU learning for a slightly different conditions. The solution is to drive it normally and if the engine speed slows down, go not touch the throttle or try to prevent it from slowing or stalling. This will allow the ECU to adjust it's map. If it repeatedly stalls then your problem is deeper and you will probably be getting a cel at this point, to be investigated. Jonathan __________________ MY 2000 Mugen Air box, Headers, Exhaust, ECU, Pressure Plate,LSD, Radiator cap NZ Dampers, Thermo SW and Thermostat. Sampco intake pipe and radiator hoses, Swift sway bars, Stillen rotors w/ M-tech extreme pads. BBS JDM Forged Wheels.w/ Potensa Re=01R's Nextgear Intake manifold gasket, SPA gauges, Alpine IDA-X001,KCE-300Bt BT Adapter, Focal 165 K2P speakers, Phoenix Gold ZX475Ti, Recaro Profi SPG w/Sparco 6 pt

04-26-2008, 11:55 PM	#12 (permalink)
SXY_S2K Trqless Join Date: Aug 2007 Location: Tempe, AZ Posts: 1,006	Yeah, I'm in AZ, and from what I've heard, all the tech's say to start it without AC on, idle to running temp, and then it's ok for AC. I always shut my AC off at least 30 secs before shutting her off too, just til idle is smooth... __________________ *Race time. Got to be serious, not stylish.* *www.myspace.com/kesmith3*

04-27-2008, 02:51 AM	#16 (permalink)
SXY_S2K Trqless Join Date: Aug 2007 Location: Tempe, AZ Posts: 1,006	It's just the ECU learning the different situations it's in... __________________ *Race time. Got to be serious, not stylish.* *www.myspace.com/kesmith3*

07-28-2004, 05:15 PM	#2 (permalink)
gqwhit27 Junior Member Join Date: Jun 2004 Posts: 1	i have an 01 and have the same annoying problem, would also be interested if anyone has an answer

07-29-2004, 02:57 PM	#3 (permalink)
ExoSpeed Junior Member Join Date: Jul 2004 Posts: 4	I have a 00 S2K and live in AZ. I have the exact same problem and am still covered under honda care. I spoke to 3 differnt dealers and they all say this is normal for even the 04's. I very much dislike the sound but, they say it normal... I'm curious as to any info on this too.

08-02-2004, 09:26 AM	#4 (permalink)
ExoSpeed Junior Member Join Date: Jul 2004 Posts: 4	I would like it if anyone had any real info on this .... come on guys.

08-18-2004, 12:47 PM	#5 (permalink)
ExoSpeed Junior Member Join Date: Jul 2004 Posts: 4	Bump... Any answers out there?

08-18-2004, 04:17 PM	#6 (permalink)
gstate Junior Member Join Date: Aug 2004 Posts: 23	anyone have a problem with the car kind of shaking at idle with the a/c on. ('01 s2k)

08-19-2004, 09:17 AM	#7 (permalink)
ExoSpeed Junior Member Join Date: Jul 2004 Posts: 4	Ya, that is what my car does just as posted above. I have found a work around kinda. It seems to happen less often if I leave my a/c off for a short time and then turn it on after I've been running for about 3-5 min. I'm not a 100% sure it's really a fix but, seems that the computer needs some time. My concern is that it caused some damage to my motor. If anyone can tell us if this IS normal as the dealer stated that would be grand. TY I'm in Arizona so, a/c is a must most of the time.

08-25-2004, 03:09 AM	#8 (permalink)
energetic Junior Member Join Date: Jul 2004 Posts: 18	I have a similar problem but with the A/C off. If am on stop and my gear is on neutral the rpm's are around 950-1000. When I step on the throttle, just a little, up to 1500rpm and then release it, the rpm's goes to 800 and can hear the engine that is going to turn off, but instead the rpm's going back to 950-1000. I though may be an adjustment was needed but when am on a still the rpm's are stable.

08-25-2004, 06:54 AM	#9 (permalink)
gstate Junior Member Join Date: Aug 2004 Posts: 23	Well, I recently had the same problem with my '01 and had it checked out. Come to find out the injector in cylinder 2 was bad and had to be replaced, so i suggest that you get it looked at.

04-26-2008, 10:41 PM	#10 (permalink)
liemha Junior Member Join Date: Apr 2008 Posts: 1	same problem here, anyone found an answer yet?

04-27-2008, 02:49 AM	#14 (permalink)
SilverS2K422 B.A.M.F. Join Date: Oct 2007 Location: Dallas, TX Posts: 578	my 02 does that too, my buddy said it might be the engine droppin back to idle, like slows down alot and drop below what its spos to be and catches itself hard to explain

04-27-2008, 02:50 AM	#15 (permalink)
SilverS2K422 B.A.M.F. Join Date: Oct 2007 Location: Dallas, TX Posts: 578	it sounded better comin out oh his mouth. lol

04-27-2008, 07:23 AM	#17 (permalink)
jagg Senior Member Join Date: Sep 2007 Location: The Endless Mountains Posts: 2,526	It sounds like the idle is just adjusting to the extra load created by running the a/c compressor..As long as it doesn't stall, I wouldn't think it's indicative of a problem. jagg

04-27-2008, 09:45 AM	#21 (permalink)
J'sS2K The Car Camera Mount Guy Join Date: Dec 2007 Posts: 806	Let it warm up to 5 bars. It does that when it's not fully warmed up.

04-27-2008, 02:46 PM	#23 (permalink)
sky2k Senior Member Join Date: Aug 2007 Location: Albuquerque Posts: 230	i have the same problem on my 01...when i first started it when i bought it, the ac was on and it did that dip to low rpms as if it were going to stall out...but its only when the ac is on for me...being a fellow desert dweller, it does get annoying, i drive the car for about a minute or two before the ac goes on, it still does it but not as bad i guess...seems normal though...i've talked to mechanics and have heard the same "fixes" mentioned above...