Sputtering During Warm-up
04-14-2008, 11:46 AM
#145
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I've tried flushing with shell and I still do, thats all I use. Just filled up today in fact, but my problem has not changed. I wish there was an end all solution, cause it sounds like nothing is getting done with the problem so few of us have.
04-14-2008, 12:42 PM
#146
^ shell was no good ! i am very happy with chevron now. also in this thread someone was using an octane booster and had no problem and when he stopped the problem appeared. so i believe it is fuel related. I will also try to clean my mafs to see it that helps.
04-15-2008, 05:44 AM
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LOL I thought (shell > chevron) meant you switched to shell. oh well, either way doesn't seem to make a difference and I was starting to lean towards MAF's as well but who knows man.
04-17-2008, 08:57 AM
#152
Originally Posted by Tac-M
MAFs are cleaned, and there is no change... hot dawg ! what is it ?! arg !
looks like the only thing that helps is octane booster. someone confirm that plz
looks like the only thing that helps is octane booster. someone confirm that plz
i'll try picking up some octane booster and running it on my next tank of gas. Any specific brand or type you want me to try?
04-17-2008, 09:18 AM
#153
Originally Posted by stylett9
i'll try picking up some octane booster and running it on my next tank of gas. Any specific brand or type you want me to try?
I ran one tank with it, and I thought it helped, then I skiped one, and I got the hesitation back. so I just fiiled up this morning and poured it in. i'll see if indeed it does anything.
04-27-2008, 12:27 PM
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I believe I have the issue that you are all talking about. Honestly I figured it was normal because it only did it while the car was warming up and am never really bothered by it. My car has been doing this from day 1 when I bought it brand new in July. I never figured it was a problem until I read this post. I am willing to bet far more people are having this issue, but don't really realize it. I was one of them.
Quite frankly it doesn't really bother me, but I will try and give descriptions of what my car does, so maybe it will help you all. When I 1st start up my car in the morning, it revs fairly high, around 2000 rpm or so. I assume this is normal since the car is cold, it slowly drops down as the car warms up. This time frame is where the issue seems to occur the worst. If I am in a parking lot, since it is reving so high, I litterally don't need to give it any gas and if I let the clutch out it will just drive itself. The sputtering, as it has been called, occurs after I give it some gas and let off of it. (Example: I'm driving in the parking lot in 1st gear, as I am giving it gas everything is fine, as soon as I let off the gas, there is not a gradual slow down, the car jerks as if the gas completely shuts off after I let off the pedal). The issue only seems to present itself in 1st or 2nd gear. If I am in 3rd gear on a stretch of road going say 40 and I let off the gas it does not do this, or if it does I haven't really noticed it. The issue is more prevalent in the winter time. (Example: when I drive to the gym it takes about 20 min. By the time I get out of the gym the car will start the sputter issue driving out of the parking lot. Today it did not do it as it is about 65 degrees. When I came out of the gym it was smooth).
I use only premium gasoline, which I believe is only 91 octane here. Personally I don't think this issue has anything to do with gas, otherwise your car would do it all the time whether it was cold or not. The only logical thing I can think of is when it is cold, it seems to be throttling itself to warm the car up and when you start driving and giving it gas, it doesn't know how to compensate between what you are doing and what it is trying to do to warm up the car. If I had to make a guess it would be something with the ECU.
Quite frankly it doesn't really bother me, but I will try and give descriptions of what my car does, so maybe it will help you all. When I 1st start up my car in the morning, it revs fairly high, around 2000 rpm or so. I assume this is normal since the car is cold, it slowly drops down as the car warms up. This time frame is where the issue seems to occur the worst. If I am in a parking lot, since it is reving so high, I litterally don't need to give it any gas and if I let the clutch out it will just drive itself. The sputtering, as it has been called, occurs after I give it some gas and let off of it. (Example: I'm driving in the parking lot in 1st gear, as I am giving it gas everything is fine, as soon as I let off the gas, there is not a gradual slow down, the car jerks as if the gas completely shuts off after I let off the pedal). The issue only seems to present itself in 1st or 2nd gear. If I am in 3rd gear on a stretch of road going say 40 and I let off the gas it does not do this, or if it does I haven't really noticed it. The issue is more prevalent in the winter time. (Example: when I drive to the gym it takes about 20 min. By the time I get out of the gym the car will start the sputter issue driving out of the parking lot. Today it did not do it as it is about 65 degrees. When I came out of the gym it was smooth).
I use only premium gasoline, which I believe is only 91 octane here. Personally I don't think this issue has anything to do with gas, otherwise your car would do it all the time whether it was cold or not. The only logical thing I can think of is when it is cold, it seems to be throttling itself to warm the car up and when you start driving and giving it gas, it doesn't know how to compensate between what you are doing and what it is trying to do to warm up the car. If I had to make a guess it would be something with the ECU.
04-27-2008, 02:52 PM
#157
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Hey guys. I've been having this problem for a while too. I'm pretty sure I know the problem and solution and based on my results this is it. First of let me just say that this isn't an ECU problem. I've flashed my ECU with OEM and custom programs and the problem remained. I'm pretty sure, based on Ed from Precision Z's insight, that the problem we're having is from water in the gas tank. Especially with gas prices so high, its not unthought of for a station to water down their gas even just a little. Even respectable stations may try to get away with it. One in the valley was shut down for this very reason.
Anyways, the problem exists and remains even after using octane booster or premium fuel is that the water never fully mixes with the fuel and just sits in the tank. My guess is that with the light pedal push like most of have when we experience the problem, we are sucking in fuel at a rate that catches some of the water sitting in the tank. At full throttle we begin sucking in more fuel and not water. I hope what I'm saying makes sense. Also once the car has been driven for a bit, the water mixes in with the fuel enough that we don't notice the problem again until the car sits for a while and the water settles again.
This would also explain why the problem is lessoned when people have used octane booster, but as also reported its only a partial fix until the next tank of fuel. What you need to try using is call heet. Its a fuel antifreeze and water absorber and WILL remove the water from your tank. I picked up two bottles of the regular heat (yellow bottle) and dumped them into a full tank of gas. By the time I had burnt through a 1/2 tank things started to get better and now that I've burnt through the whole tank and refueled, the problem seems to be gone. Heet can be found at any pep boys or autozone and can also be found here: http://www.goldeagle.com/heet/index.htm
Hopefully this works for everyone. Good luck.
-Doug
Anyways, the problem exists and remains even after using octane booster or premium fuel is that the water never fully mixes with the fuel and just sits in the tank. My guess is that with the light pedal push like most of have when we experience the problem, we are sucking in fuel at a rate that catches some of the water sitting in the tank. At full throttle we begin sucking in more fuel and not water. I hope what I'm saying makes sense. Also once the car has been driven for a bit, the water mixes in with the fuel enough that we don't notice the problem again until the car sits for a while and the water settles again.
This would also explain why the problem is lessoned when people have used octane booster, but as also reported its only a partial fix until the next tank of fuel. What you need to try using is call heet. Its a fuel antifreeze and water absorber and WILL remove the water from your tank. I picked up two bottles of the regular heat (yellow bottle) and dumped them into a full tank of gas. By the time I had burnt through a 1/2 tank things started to get better and now that I've burnt through the whole tank and refueled, the problem seems to be gone. Heet can be found at any pep boys or autozone and can also be found here: http://www.goldeagle.com/heet/index.htm
Hopefully this works for everyone. Good luck.
-Doug
04-27-2008, 03:24 PM
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The water at the bottom of the tank sounds possible, but I don't think that is my problem. I still believe it is some sort of throttle control issue. The sputtering description isn't really a good way to describe it. It's not really sputtering.
1. My car has no problems idling. When I first start it up I don't press the gas. I would think if water was settling at the bottom, my car would be sputtering out and on the virge of dieing since it would be sucking in all that fresh water.
2. I own 2 other cars and go to the same gas stations. Neither of those cars have this problem.
1. My car has no problems idling. When I first start it up I don't press the gas. I would think if water was settling at the bottom, my car would be sputtering out and on the virge of dieing since it would be sucking in all that fresh water.
2. I own 2 other cars and go to the same gas stations. Neither of those cars have this problem.
04-27-2008, 05:57 PM
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Maybe I'm wrong, but each bottle of Heet costs $1.50, so for $3.00 you can try and see if it works or you can wait to see what else people come up with. Just like a few others here my car was at the dealership for the problem with the only answer being "could not duplicate."
The water problem was suggested by someone who's been working on Zs for 28+ years and who the owner of Sage Auto Group (West Covina Nissan) takes his cars to because he doesn't trust his own mechanics, so this isn't just me making this up.
I'll say it again, I had this same problem exactly as its been described here and it was actually getting quite violent at times. I used to bottles of heet which cost only $3.00 and it worked.
The water problem was suggested by someone who's been working on Zs for 28+ years and who the owner of Sage Auto Group (West Covina Nissan) takes his cars to because he doesn't trust his own mechanics, so this isn't just me making this up.
I'll say it again, I had this same problem exactly as its been described here and it was actually getting quite violent at times. I used to bottles of heet which cost only $3.00 and it worked.