10v low rpm misfire
03-09-2013, 03:24 PM
#11
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You need to check your fault codes if want find anything out about the knock sensor. Idle switches http://audi.humanspeakers.com/tuning-cise.htm#g
Last edited by yodasfro; 03-09-2013 at 03:32 PM.
03-09-2013, 07:54 PM
#12
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OK, then. All snarky jabs aside...
One of the best lessons I ever learned working on my first rides was the following.:
"If it's bad when it slow, and it's still bad when it's fast, your problem is electrical or electronic. (Plugs, coils, nowadays sensors too)"
"If it's bad when it's slow and it's worse when it's fast, your problem is mechanical/metal. (Valves, seats, bearings)"
"If it's bad when it's slow and it gets better when it's fast, it's fuel/air. (carb/injectors, intake leaks)"
The reason we know it's an intake leak is because you only have the issue at low rpm. The intake leak is allowing copious amounts of extra air to be sucked into your combustion chamber, causing you to run very lean.
The reason you run more normally at higher rpm is because at higher rpm, your injectors are also dumping copious amounts of fuel into the combustion chamber as well. Or, at least enough fuel to mostly compensate for the extra air.
It's the mostly you're feeling when you say you're running sluggish. There is still too much air leaking in, and your injectors can't compensate. That means, when you get on the throttle to accelerate, the engine still runs, but feels like it doesn't have much power.
So, in all sincerity, this is why I really think it's a disconnect between your air filter and your engine-mounted intake.
And, if the car is pulling that much extra air into the combustion chamber, what do you think will happen if it pulls in a big ol' whiff of propane, too?
You ever bent over and lit one of your own farts on fire? Yeah... me neither. Now, I'm certainly not sayin' I didn't enjoy watching my drunk friends do it in college. But I didn't want to wake up 3 days in a row with the smell of burnt assal hair being the first sensory experience I received each morning. I'm trying to save you from a similar experience, here... Only difference is, if you use propane to test an intake leak, it'll be your eyebrows that end up gone. The smell will still remain, and all the world will be able to bear witness to your mechanical indiscretion, as burnt-off eyebrows take weeks to grow back.
So, please forgive me for invoking mechanical Darwinism when I made fun of you. I was simply trying to prevent you from hurting yourself and your daily driver.
Bung,
LG
One of the best lessons I ever learned working on my first rides was the following.:
"If it's bad when it slow, and it's still bad when it's fast, your problem is electrical or electronic. (Plugs, coils, nowadays sensors too)"
"If it's bad when it's slow and it's worse when it's fast, your problem is mechanical/metal. (Valves, seats, bearings)"
"If it's bad when it's slow and it gets better when it's fast, it's fuel/air. (carb/injectors, intake leaks)"
The reason we know it's an intake leak is because you only have the issue at low rpm. The intake leak is allowing copious amounts of extra air to be sucked into your combustion chamber, causing you to run very lean.
The reason you run more normally at higher rpm is because at higher rpm, your injectors are also dumping copious amounts of fuel into the combustion chamber as well. Or, at least enough fuel to mostly compensate for the extra air.
It's the mostly you're feeling when you say you're running sluggish. There is still too much air leaking in, and your injectors can't compensate. That means, when you get on the throttle to accelerate, the engine still runs, but feels like it doesn't have much power.
So, in all sincerity, this is why I really think it's a disconnect between your air filter and your engine-mounted intake.
And, if the car is pulling that much extra air into the combustion chamber, what do you think will happen if it pulls in a big ol' whiff of propane, too?
You ever bent over and lit one of your own farts on fire? Yeah... me neither. Now, I'm certainly not sayin' I didn't enjoy watching my drunk friends do it in college. But I didn't want to wake up 3 days in a row with the smell of burnt assal hair being the first sensory experience I received each morning. I'm trying to save you from a similar experience, here... Only difference is, if you use propane to test an intake leak, it'll be your eyebrows that end up gone. The smell will still remain, and all the world will be able to bear witness to your mechanical indiscretion, as burnt-off eyebrows take weeks to grow back.
So, please forgive me for invoking mechanical Darwinism when I made fun of you. I was simply trying to prevent you from hurting yourself and your daily driver.
Bung,
LG
Last edited by Loudgoldwing; 03-09-2013 at 08:31 PM.
03-09-2013, 10:58 PM
#13
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To doug: yes I've driven it around. I've had to get to work and back the last two days. I've put about 30 miles on it and have had no change.
Yoda: Thanks for the link. Ill check to see what the throttle switch is doing. I don't know how to check for codes on this car. Im guessing its similar to a cis vw where it gives you flashes. If you have a link that would be awesome, but if not ill do a search and find it when I get back from work tomorrow.
Loudgoldwing: I already understand what an intake leak is and I understand that my intake is most likely pulling in unmetered air based on the symptoms. It was the first thing I started checking for when I heard the way the car was running. The reason I was using propane was because that's what I've read on multiple forums to use to check for vacuum leaks. Which I understand that its not a vacuum leak in the normal sense, but it is pulling in vacuum threw something which is clearly throwing off my air to fuel ratio. If the car was going to burn my eyebrows off wouldn't it have done that the first time I tried to start it? Gasoline and propane are both gases. Pulling in the propane would raise the idle as its giving the engine more fuel and evening out the a/f ratio. And plus last I checked combustion happens in the cylinder head not outside of it. I didn't just pull the propane torch out and say "hey I bet this is a good idea" I did it based off research I did prior to try and find where the unmetered air was coming from. Thank you for the concern though, I appreciate the advice.
Yoda: Thanks for the link. Ill check to see what the throttle switch is doing. I don't know how to check for codes on this car. Im guessing its similar to a cis vw where it gives you flashes. If you have a link that would be awesome, but if not ill do a search and find it when I get back from work tomorrow.
Loudgoldwing: I already understand what an intake leak is and I understand that my intake is most likely pulling in unmetered air based on the symptoms. It was the first thing I started checking for when I heard the way the car was running. The reason I was using propane was because that's what I've read on multiple forums to use to check for vacuum leaks. Which I understand that its not a vacuum leak in the normal sense, but it is pulling in vacuum threw something which is clearly throwing off my air to fuel ratio. If the car was going to burn my eyebrows off wouldn't it have done that the first time I tried to start it? Gasoline and propane are both gases. Pulling in the propane would raise the idle as its giving the engine more fuel and evening out the a/f ratio. And plus last I checked combustion happens in the cylinder head not outside of it. I didn't just pull the propane torch out and say "hey I bet this is a good idea" I did it based off research I did prior to try and find where the unmetered air was coming from. Thank you for the concern though, I appreciate the advice.
03-10-2013, 08:30 AM
#14
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I love it when the new kids ask for help because they can't figure out what they messed up, and then act like they're insulted by the simplicity of the solution.
I can only give you an answer based on the info I'm given. And, based on the info I've been given, I gave you an answer. It was a good answer. Like it or not, insulted as you are by my method of delivery, it was also the correct answer.
So what if I try to keep the lurkers entertained a little bit by throwing some humor into the mix at the (minor) expense of your mechanical manhood...? Kind of a small price to pay for getting solid advice.
Don't worry, though. I always admit when I'm wrong. And I'm eager to do so when your vastly superior knowledge base and diagnostic skills eventually lead you to a miracle solution that has nothing to do with an intake leak.
Why, you ask? Because I like learning new things from people smarter than me. Even when they break my ***** a little in exchange for the wisdom. It means they do all the hard work, and all I have to do is remember.
So, I look forward to remembering all of the knowledge you're sure to share, since the only purpose I have apparently served is to bruise your ego.
Good luck,
LG
I can only give you an answer based on the info I'm given. And, based on the info I've been given, I gave you an answer. It was a good answer. Like it or not, insulted as you are by my method of delivery, it was also the correct answer.
So what if I try to keep the lurkers entertained a little bit by throwing some humor into the mix at the (minor) expense of your mechanical manhood...? Kind of a small price to pay for getting solid advice.
Don't worry, though. I always admit when I'm wrong. And I'm eager to do so when your vastly superior knowledge base and diagnostic skills eventually lead you to a miracle solution that has nothing to do with an intake leak.
Why, you ask? Because I like learning new things from people smarter than me. Even when they break my ***** a little in exchange for the wisdom. It means they do all the hard work, and all I have to do is remember.
So, I look forward to remembering all of the knowledge you're sure to share, since the only purpose I have apparently served is to bruise your ego.
Good luck,
LG
03-10-2013, 09:40 AM
#15
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I'm not in the least bit insulted by the advice that you have given me and to be frank I could care less about my manhood. In fact I've said a few times that it makes perfect sense and that I will go back threw everything I've done to try and find where my leak is coming from. I understand that I'm not perfect and know that I make mistakes. The only gasket I have left to check is the lower intake manifold gasket. I'm sorry to have brought your sarcasm out in your post, but I'm just trying to explain myself the best I can and explain why I have checked and done the things I've done so far. I'm not sure why you took my post as sarcasm.. I even thanked you for being concerned. Sorry you couldn't handle my humor at your expense as it seems to have made you a bit butt hurt. I'm sorry we got off on the wrong foot as clearly you are a knowledgeable person. Let me say that I am no new kid with cars, I am simply a newcomer to these boards. I am much more used to Volkswagen's, albeit not much different then some Audi's, they are a bit more simple.
As I've said I have checked multiple times for any spots on the intake boot that could be cracked and pulling in air. There are no visible ones and no spots that I can find are pulling air in. Unless you have a better way to check it then I'm not sure what else to do to find them. I'm also going to check the throttle body and the gasket placement when I check the lower manifold gasket later today.
As I've said I have checked multiple times for any spots on the intake boot that could be cracked and pulling in air. There are no visible ones and no spots that I can find are pulling air in. Unless you have a better way to check it then I'm not sure what else to do to find them. I'm also going to check the throttle body and the gasket placement when I check the lower manifold gasket later today.
03-19-2013, 09:11 AM
#16
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Figured I should update as I still haven't solved this. So I went back threw and reseated all my gaskets and replaced a hose from my isv to my cold start valve as it looked cracked. I also sealed anything that looked like a crack in my intake boot. The car started and ran a bit stronger then it had before. It still had the same problem, but it wasn't quite as bad. So I took it for a ride to work and back to go grab my paycheck and when I got home I popped the hood to check everything out on it. I unplugged my isv while it was running to see if that would sort my problem out and my idle jumped to around 1200 from the 900 it had been at and sounded even as can be. It was also quite a bit more responsive to throttle input. I didn't try driving it like this, but it seemed to run a bit healthier with it unplugged. So after unplugging and re connecting a few other sensors to see the outcome and not really having much luck I shut the car off and went to bed. I got up around 6 hours later to head out to work and I got in the car turned the key and nothing. It cranked and cranked and cranked but it would not fire. It didn't even start to fire. I have no idea why it would go from being able to start and run to not even wanting to fire within 6 hours without me making any changes to anything. I plugged every sensor back in and nothing looks out of the ordinary. So im leaning more toward spark at this point. I smell gas so my fuel pump and injectors are still working. Im going to grab a new set of plugs just for the hell of it and check that im getting spark with those.
03-19-2013, 03:32 PM
#17
AudiWorld Super User
fuel pump/relay?
btw, i want to c this propane trick (slowing getting my cellphone out and getting it ready for some awesomeness :-D) ive always used starting fluid (not brake fluid, as now its not flammable :'-( anymore) and kept my face as far away from it as i can. also, propane is a heavy and allot more flammable substance then gasoline, so a small spark from your distributor or cracked spark plug wire will turn you and your car in to a.... well, nothing pretty
btw, i want to c this propane trick (slowing getting my cellphone out and getting it ready for some awesomeness :-D) ive always used starting fluid (not brake fluid, as now its not flammable :'-( anymore) and kept my face as far away from it as i can. also, propane is a heavy and allot more flammable substance then gasoline, so a small spark from your distributor or cracked spark plug wire will turn you and your car in to a.... well, nothing pretty
03-19-2013, 06:45 PM
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As stated I am getting fuel. I might pull the injectors again if im getting spark to check and make sure that they are flowing correctly and have proper spray pattern, but I did spend a day letting them soak in sea-foam and then hit them with some berrymans b-12 the day after for good measure. I can tell just by the smell from my engine bay. Gas is the one prevalent smell when I went to the front of the car after trying to start it.
I only tried the propane thing for a minute or two as frankly it scared me as well, but I had researched it a bit before attempting it. Numerous different message boards had said this is the best method to use based on what I said earlier.
I only tried the propane thing for a minute or two as frankly it scared me as well, but I had researched it a bit before attempting it. Numerous different message boards had said this is the best method to use based on what I said earlier.
03-20-2013, 03:46 AM
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Yea I unplugged the isv, throttle switch and one sensor located on top of the intake boot. Ill double check them and make sure they are alright. All connectors have been dielectric greased previously so I don't see how it would have fried, but ill take a look anyways.