Cold start misfire
06-11-2011, 10:29 AM
#1
Radical Member
Thread Starter
Cold start misfire
Hey guys. Just bought an 06 with 45,000 miles. Runs great except when I first start it in the morning. It seems to idle a bit rough for the first minute it so. What should I look into? Idle control?
06-11-2011, 10:34 AM
#2
the overexplainer
unless a check engine light comes on, it's completely normal.
The car intentionally misfires to warm up the catalytic converters faster. You're alright.
and grats on the car purchase.
The car intentionally misfires to warm up the catalytic converters faster. You're alright.
and grats on the car purchase.
07-10-2011, 04:54 AM
#5
3rd Gear
Join Date: Jul 2011
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I don't believe this is normal.. my '05 does it too, and with my scanner, I see, even after it's warmed up and not missing, the eng. is VERY lean. The short term fuel is around +17%, which is right on the border of a check eng. lite issue, AND last spring the rear cat had to be replaced because of a melt down. it's been to the dealer for plugs, 4 o2's, the rear cat, pcv, and it STILL does the same thing. Mileage is till good, but i can't believe that the bank 1 cat will last long under these conditions.. i'll keep digging and re-post!
07-10-2011, 05:51 AM
#6
One other poster had said they had seen documentation indicating that the TL would intentionally misfire when cold, to which I replied, show me the documentation..................I'm still waiting for the proof as it would be hard to come by if it doesn't exist.
Just a sidebar-Our RX7 Turbo is designed to rev to 2700 when first started, winter or summer, so the precat can warm up quickly, another environmental necessity. As we purchased the car new, this has never been to my liking, seeing a cold vehicle rev to 2700, so one can stop the extremely high idle by starting the car when the trans is in first gear, as long as it's a manual, and it will rev to 1300, then drop down normally.
07-11-2011, 07:24 PM
#7
Team Owner
First, I’d certainly like to put to rest the theory that anyone would even believe a manufacturer would develop a vehicle that would intentionally misfire period, let alone being done to warm up the cats, as raw gas is a killer for the converters. The converters are placed near the engine for a good reason; they heat up and become effective very quickly with the high idle speed generating heat quickly. When warm, raise the idle to 1200 and see how it feels, as it certainly isn't smooth, at least on the numerous TL's I've seen, just the nature of the beast with the “lean burn” engine.
The converters are bolted to the heads and along with the close proximity, the misfires light them off extremely quick. Timing is also retarded and the mixture is very lean There are videos on here of how quickly the TL goes into closed loop and how lean it runs from the time the 02s light off.
I agree that the TL tends to have a rougher idle than some "luxury" cars. I also think that the people with bad/broken mounts will notice this misfire more.
It's not exactly a "lean burn" engine in the traditional sense. It goes out to between 15:1 and 16:1 AF on cold start but for most running it's right at 14.7. It doesn't like to go into power enrichment as easily as most others but once into vtec it dips into the 11 range.
If you notice, the TL has a much lower idle when cold than most cars. This is another fuel conserving part of ULEV-2. I've had mine in 12F (I know, not cold for some people but unbearable for me) and idle was 1,200 and only for a minute.
Just a sidebar-Our RX7 Turbo is designed to rev to 2700 when first started, winter or summer, so the precat can warm up quickly, another environmental necessity. As we purchased the car new, this has never been to my liking, seeing a cold vehicle rev to 2700, so one can stop the extremely high idle by starting the car when the trans is in first gear, as long as it's a manual, and it will rev to 1300, then drop down normally.
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07-11-2011, 07:47 PM
#8
How are you putting it to rest? Yes, the ECU intentionally misfires to dump raw fuel into the cat to light it off quicker. Sure, this will burn them up if it goes on for long periods of time but you're talking from a cold start for maybe 30sec to 1 minute and it's not a constant misfire. Think about when a car has a random misfire during normal operation after the cats are hot, it doesn't kill them unless it happens often. The cold start strategy is not heating them up any hotter than normal running temp, it's just getting them up to full temp as quickly as possible.
The converters are bolted to the heads and along with the close proximity, the misfires light them off extremely quick. Timing is also retarded and the mixture is very lean There are videos on here of how quickly the TL goes into closed loop and how lean it runs from the time the 02s light off.
I agree that the TL tends to have a rougher idle than some "luxury" cars. I also think that the people with bad/broken mounts will notice this misfire more.
It's not exactly a "lean burn" engine in the traditional sense. It goes out to between 15:1 and 16:1 AF on cold start but for most running it's right at 14.7. It doesn't like to go into power enrichment as easily as most others but once into vtec it dips into the 11 range.
If you notice, the TL has a much lower idle when cold than most cars. This is another fuel conserving part of ULEV-2. I've had mine in 12F (I know, not cold for some people but unbearable for me) and idle was 1,200 and only for a minute.
I saw it in a generic ULEV manual and for the TL specifically at a friend's smog shop. If you want to find it online, I suggest looking at the smog end of things.
Agreed, I would hate that. My GF's Murano shoots up to 2,500rpm at only 40F and while I wait for it to go down, she gets it into reverse or drive quicker than any normal human can. I've tried to tell her since it was new to wait for the idle to go down but it did no good and now I'm getting the "I told you so" since it now has 45K on it and no problems.
The converters are bolted to the heads and along with the close proximity, the misfires light them off extremely quick. Timing is also retarded and the mixture is very lean There are videos on here of how quickly the TL goes into closed loop and how lean it runs from the time the 02s light off.
I agree that the TL tends to have a rougher idle than some "luxury" cars. I also think that the people with bad/broken mounts will notice this misfire more.
It's not exactly a "lean burn" engine in the traditional sense. It goes out to between 15:1 and 16:1 AF on cold start but for most running it's right at 14.7. It doesn't like to go into power enrichment as easily as most others but once into vtec it dips into the 11 range.
If you notice, the TL has a much lower idle when cold than most cars. This is another fuel conserving part of ULEV-2. I've had mine in 12F (I know, not cold for some people but unbearable for me) and idle was 1,200 and only for a minute.
I saw it in a generic ULEV manual and for the TL specifically at a friend's smog shop. If you want to find it online, I suggest looking at the smog end of things.
Agreed, I would hate that. My GF's Murano shoots up to 2,500rpm at only 40F and while I wait for it to go down, she gets it into reverse or drive quicker than any normal human can. I've tried to tell her since it was new to wait for the idle to go down but it did no good and now I'm getting the "I told you so" since it now has 45K on it and no problems.
07-11-2011, 08:29 PM
#9
Senior Moderator
Matt-You are the one that stated you would get me the evidence, still waiting, as no matter how much you print the contrary, there will be no misfire when cold, and 1200 is not much different than any other car when in cold idle. I'm too lazy to hook up the test equipment, but one member did and stated no misfire when cold and I believe, with their location, the cats get hot enough with just the engine running for a short period.
If you want proof of the car misfiring and dumping fuel to warm up the cats, ask anyone who has gotten rid of all 3 of their catalysts what happens at the exhaust pipe when they start cold. They will all tell you that it looks like the car is pissing fuel.
07-11-2011, 10:20 PM
#10
My car is louder when I first start it in the morning but, the AFR gauge takes 15 seconds to warm up so I can't see the AFR at cold start up. I have never looked to see of gas was coming out of the tail pipe. I have started the car cold with the exhaust cut out open and it sounds horrible and extreamly loud.
07-12-2011, 05:53 AM
#11
Everyone has their opinions but no proof, let's go guys; enough has been said about the misfire, so let's put up. I know whenever I state something; somebody needs proof, so now it’s my turn.
Let's put it to rest and show me the proof, and not someone just stating their reason or philosophy on the subject. If in the owner’s manual, FSM, or any repair manual, please direct me where the information can be found. I'll be waiting.
07-12-2011, 08:29 AM
#12
Team Owner
Matt-You are the one that stated you would get me the evidence, still waiting, as no matter how much you print the contrary, there will be no misfire when cold, and 1200 is not much different than any other car when in cold idle. I'm too lazy to hook up the test equipment, but one member did and stated no misfire when cold and I believe, with their location, the cats get hot enough with just the engine running for a short period.
I was talking with the guy just a month ago. He's now one of the "smog police", kind of on the other side of things now but we were going over some of this stuff and the misfires were brought up. That's what I hate in this day and time, you can read it in an official manual but if it's not online it's not true.
07-12-2011, 10:02 AM
#13
I've read the paper on it already. I don't really hang out at smog shops often. I'm satisfied with what I read, if you really want proof, research it. I've never seen it online but I have seen it from what I consider a better source. What do I have to gain by lying about whether or not a car misfires when cold? It's not one of life's great questions mysteries.
I was talking with the guy just a month ago. He's now one of the "smog police", kind of on the other side of things now but we were going over some of this stuff and the misfires were brought up. That's what I hate in this day and time, you can read it in an official manual but if it's not online it's not true.
I was talking with the guy just a month ago. He's now one of the "smog police", kind of on the other side of things now but we were going over some of this stuff and the misfires were brought up. That's what I hate in this day and time, you can read it in an official manual but if it's not online it's not true.
07-12-2011, 10:47 AM
#14
Team Owner
Your answer is the same as before, but you did offer to get me the needed information so I’m still waiting. Amazing, no TSB, no indication at all in the FSM, nor any document on line, nor in any reference material I have, so must be from an underground source. I don't doubt you think it's a misfire as information has been supplied to you from some source and has been bantered around on this forum for quite some time, but once again, let's do some searching and fess up with the documentation. You are correct though, if I don't see evidence, especially in this matter, I don't believe it.
There are several things I state around here that aren't readily available by google and probably never will be. One is knowing one of the Ford engineers on the modular design team and yes, inside info on the 5w-20 wear results in those engines with more than 100 engines tested. You will likely never see the results on the internet so you can choose to believe the info I pass on or not.
It's kind of like when Paul posted over on bitog that the TL has dangerously low oil pressure on 5w20 when fully hot even when stock, they jumped all over him. Apparently google holds more weight than real world data.
Anyone can post anything on the internet, it doesn't make it right. I got the misfire info from a manual which is better than any source found on the internet.
Here's a hint, if you have a 15-16:1 AFR on a stone cold engine, you're going to have an unstable idle with random misfires.
Last edited by I hate cars; 07-12-2011 at 10:52 AM.
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Undying Dreams (06-28-2012)
07-12-2011, 02:40 PM
#16
Great video with the A/F ratio and RPM.
Last edited by Turbonut; 07-12-2011 at 02:45 PM.
07-12-2011, 04:45 PM
#17
Great. Didn't have the sound on when listening before, but certainly sounds like it's running on all cylinders, no cold start misfire. Actually sounds pretty healthy. Initially leans to 15.3 for a moment then as with any cold idle, mixture turns rich, down to 13.1, then idle drops and mixture goes up to the normal 14.8/15. Perfectly normal.Guess we'll wait for a reply.
07-12-2011, 05:32 PM
#18
Team Owner
I've seen the proof. I'm sorry you can't research anything beyond the internet. Show me proof it doesn't misfire... Do your own research. There is a real world out there beyond the internet. There are such things as books and people in the industry. You could try leaving your computer and get out in the real world instead of following me around.
07-12-2011, 05:34 PM
#19
Team Owner
Great. Didn't have the sound on when listening before, but certainly sounds like it's running on all cylinders, no cold start misfire. Actually sounds pretty healthy. Initially leans to 15.3 for a moment then as with any cold idle, mixture turns rich, down to 13.1, then idle drops and mixture goes up to the normal 14.8/15. Perfectly normal.Guess we'll wait for a reply.
07-13-2011, 05:44 AM
#20
I love how you follow me around desperately trying to prove me wrong in every post I make. Show me proof it doesn't misfire... Do your own research. There is a real world out there beyond the internet. There are such things as books and people in the industry. You could try leaving your computer and get out in the real world instead of following me around.
The coolant temperature is detected by the water temperature sensor and as the lower the water temperature, fuel vaporization becomes worse, therefore, the air-fuel mixture is made richer by lengthening the injector duty cycle.
When the water temp is up to normal, the feedback system using the O2 sensor information and the ecu changes the duty cycle of the injectors to correct the condition, longer duty cycle if a lean condition is noticed, and a shorter duty cycle if too rich. As one can see in the video, the injection cycle varies and makes a gradual transition through the A/F range all do to the injector duty cycle.
There's the proof, so just as I surmised, no misfire when cold. Guess Ill wait to see if you have some other words of wisdom to add, and no, I'm not blind and I don't follow you or anyone around to prove them wrong. I only want the members to get the correct answer to a specific question.
Last edited by Turbonut; 07-13-2011 at 05:52 AM.
07-13-2011, 09:25 AM
#21
Team Owner
You've got to be kidding? Do you really know what you're talking about as sometimes I have my doubts? If you seriously believe that the cold A/F ratio is made richer because of a misfire, got to go back to the classroom.
The coolant temperature is detected by the water temperature sensor and as the lower the water temperature, fuel vaporization becomes worse, therefore, the air-fuel mixture is made richer by lengthening the injector duty cycle.
When the water temp is up to normal, the feedback system using the O2 sensor information and the ecu changes the duty cycle of the injectors to correct the condition, longer duty cycle if a lean condition is noticed, and a shorter duty cycle if too rich. As one can see in the video, the injection cycle varies and makes a gradual transition through the A/F range all do to the injector duty cycle.
There's the proof, so just as I surmised, no misfire when cold. Guess Ill wait to see if you have some other words of wisdom to add, and no, I'm not blind and I don't follow you or anyone around to prove them wrong. I only want the members to get the correct answer to a specific question.
The coolant temperature is detected by the water temperature sensor and as the lower the water temperature, fuel vaporization becomes worse, therefore, the air-fuel mixture is made richer by lengthening the injector duty cycle.
When the water temp is up to normal, the feedback system using the O2 sensor information and the ecu changes the duty cycle of the injectors to correct the condition, longer duty cycle if a lean condition is noticed, and a shorter duty cycle if too rich. As one can see in the video, the injection cycle varies and makes a gradual transition through the A/F range all do to the injector duty cycle.
There's the proof, so just as I surmised, no misfire when cold. Guess Ill wait to see if you have some other words of wisdom to add, and no, I'm not blind and I don't follow you or anyone around to prove them wrong. I only want the members to get the correct answer to a specific question.
Last edited by I hate cars; 07-13-2011 at 09:27 AM.
07-13-2011, 09:26 AM
#22
Team Owner
I'll beat you to the punch.... Your next post will have something to do with going to breakfast.... You do that every time you're wrong.
07-13-2011, 10:09 AM
#23
I gave you more credit than I should have. A misfire causes the 02 to read rich momentarily. It's called a false rich condition. I thought this was common knowledge but I guess not. Thanks for the half assed kindergarden explanation of EFI and closed loop operation. Would you like me to pick apart your explanation too?
I'm tired of responding to your ridiculous replies. Stay with the ATF and oil threads as you can try and bamboozle the people more easily. I’m done with this nonsense.
07-13-2011, 11:45 AM
#24
the overexplainer
Guess I cant assume Mods know everything.
07-13-2011, 12:53 PM
#25
Team Owner
Raw fuel kills converters due to overheating. It's not the fuel itself. However, when the converter is dead cold, raw fuel can heat it up quicker. The temp does not exceed normal running temps, it's only used for quicker lightoff.
07-13-2011, 01:00 PM
#26
Team Owner
Bamboozle people? What exactly do you think I have to gain by helping people? I've contributed something along with Inaccurate- The cure to the Honda 5at failures. What have you contributed? Yep, you got me, I want to trick people into thinking there's a cold start misfire and that Z1 sucks. I have so much to gain by spending hours of my time answering the same questions over and over again. Do you realize how stupid that statement is?
06-28-2012, 01:03 PM
#27
I mod my car in
So after reading this thread the question i have is: When i start my car i get a CEL stating i have a misfire. It only happens first thing in the morning or after work (sitting for 8 hours). I recently changed my spark plugs so it has to be a coil pack right? My question is as follows: What is the best way to find out what coil pack it is being that this only happens on cold starts and not every cold start? Is there a way to test each coil pack with a volt meter? Any help is appreciated.
06-28-2012, 01:26 PM
#28
Team Owner
Usually ignition problems show up as temperatures rise.
Usually idle misfires that go away with rpm are compression related.
Either of those statements are not always true but usually.
The car can be running lean on a cold start causing the misfire and then be ok when it warms up. That could be a couple things, first thing to check would be your fuel trims on a scanner.
The ECU will probably have a code for exactly which cylinder is misfiring.
How does it run at full throttle?
When you first start it on a cold start, hold the rpms steady at 1,500-2,000rpm and see if it still misfires.
Usually idle misfires that go away with rpm are compression related.
Either of those statements are not always true but usually.
The car can be running lean on a cold start causing the misfire and then be ok when it warms up. That could be a couple things, first thing to check would be your fuel trims on a scanner.
The ECU will probably have a code for exactly which cylinder is misfiring.
How does it run at full throttle?
When you first start it on a cold start, hold the rpms steady at 1,500-2,000rpm and see if it still misfires.
06-28-2012, 01:39 PM
#29
I mod my car in
Usually ignition problems show up as temperatures rise.
Usually idle misfires that go away with rpm are compression related.
Either of those statements are not always true but usually.
The car can be running lean on a cold start causing the misfire and then be ok when it warms up. That could be a couple things, first thing to check would be your fuel trims on a scanner.
The ECU will probably have a code for exactly which cylinder is misfiring.
How does it run at full throttle?
When you first start it on a cold start, hold the rpms steady at 1,500-2,000rpm and see if it still misfires.
Usually idle misfires that go away with rpm are compression related.
Either of those statements are not always true but usually.
The car can be running lean on a cold start causing the misfire and then be ok when it warms up. That could be a couple things, first thing to check would be your fuel trims on a scanner.
The ECU will probably have a code for exactly which cylinder is misfiring.
How does it run at full throttle?
When you first start it on a cold start, hold the rpms steady at 1,500-2,000rpm and see if it still misfires.
Since you say compression please check out this thread, my other problem is toward the end. Sorry to cross threads
https://acurazine.com/forums/3g-tl-problems-fixes-114/engine-misfiring-625457/
I have no idea how to check my fuel trims on a scanner
The only code i get is PO300 - PO306 and every cyl in between.
Car runs good at full throttle
I have held it steady and in the past and the car was fine.
I have all these problems lately from the misfire to the skunk smell to the prong that was missing off of a spark plug a few months back...i guess 1 step at a time.
08-07-2012, 09:30 AM
#30
I mod my car in
So i still have this issue and it happens every couple of days. Could running rich be the problem? I'm just about ready to bring this car to the dealership to get it fixed which i'm not thrilled about but at least it will be fixed fast instead of guessing.
08-07-2012, 12:34 PM
#31
Instructor
I'm not picking a side in this war, but I've noticed that my car (stock exhaust) smells like it's running rich on cold start up. I'm not sure that "misfiring" is the way I'd describe it, though. There's a big difference between misfiring and "running rich on startup." (which all my fuel-injected cars seem to do.)
10-22-2012, 03:14 PM
#32
1st Gear
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Has anyone figured this out? My '04 6speed does the same thing. It also has all the associated pending codes. If it was an acceptable misfire it would not create a code(pending or CEL). I understand that people have different opinions but its not helping the rough idle problem.
02-08-2013, 10:23 AM
#33
hi, new member here, picked up an 05 acura rl. I'm having issues ever since i bought the car from a small dealership a few weeks back and have had to take it back 3 times. still not fixed. i noticed at a cold start the check engine light will come on aslong as the sh-awd light with a misfire code. they changed the plugs, changed one coil pack, did a valve adjustment, even changed a cat. still this morning it came back on. has anyone had this kind of issue. any help would be appreciated.
02-08-2013, 03:24 PM
#35
Its looking to be that way. I just dont want to pay for it. The dealership should be taking care of this. I was just trying to get feedback if anyone has had this same situation.
02-08-2013, 03:40 PM
#37
haha this is very true, yeah i've talked to the mechanic and he asked me to drop it off again for the 4TH TIME!!! i'm going to drop it off and see what happens. i told them to take it to acura and have it diagnosed since they can't seem to solve this problem. he said thats what they might do. i just want my car fixed or my money back!
02-08-2013, 06:13 PM
#38
hi, new member here, picked up an 05 acura rl. I'm having issues ever since i bought the car from a small dealership a few weeks back and have had to take it back 3 times. still not fixed. i noticed at a cold start the check engine light will come on aslong as the sh-awd light with a misfire code. they changed the plugs, changed one coil pack, did a valve adjustment, even changed a cat. still this morning it came back on. has anyone had this kind of issue. any help would be appreciated.
02-09-2013, 01:52 PM
#39