RYRO14

iTrader: (1)

Low 30's. Im thinking it could be winter blended gasoline

Zander916

I'm starting to think that too now... Especially since researching about winter blended gas. It seems it's more volatile meaning it turns to vapor easier. Soooo.... what makes sense to me if you combine what the dealer has told us about the high pressure pumps and what we know about winter blended gas. Maybe as it sits for all that time some turns to vapor. Therefore it's not easily pumped and then the high pressure pump has sort of a hiccup as it loses pressure for just a moment. Maybe what we're hearing is cavitation? http://www.answers.com/topic/cavitation Had to learn about that crap in college. On big pumps it sounds like someone threw in a bunch of rocks into the pump. If bad enough on those pumps it can actually cause damage.

I know my ideas are all over the place but thanks to others input I think we're slowly coming to a conclusion here.

Here's a short explanation of cavitation from that same link:

"cavitation
Formation of vapour bubbles within a liquid at low-pressure regions that occur in places where the liquid has been accelerated to high velocities, as in the operation of centrifugal pumps, water turbines, and marine propellers. Cavitation is undesirable because it produces extensive erosion of the rotating blades, additional noise from the resultant knocking and vibrations, and a significant reduction of efficiency because it distorts the flow pattern. The cavities form when the pressure of the liquid has been reduced to its vapour pressure; they expand as the pressure is further reduced along with the flow, and they suddenly collapse when they reach regions of higher pressure."

Here's a couple of interesting videos. This one uses a special camera to show the cavitation on a propeller. http://www.youtube.com/watch?v=mQvbispmUF4

This is a slow-mo of cavitation within a water droplet. It kind of shows the enormous energy this has. It's like little (water) hammers beating the crap out of the surface it collapses on. http://www.youtube.com/watch?v=x7ECCyEvjPA

I know that's a lot of info but I wanted to be thorough and see what some of you thought. Sounds possible to me. I know mechanical pumps on older cars used to vapor lock from heat turning the gas to vapor

On a side note, I did change my oil filter today (not the oil) at 70% life. Once again the pleats were starting to buckle. I was using Bosch filters. This time I bought a Wix Gold filter. I happened to notice a very significant design difference on the inside of the filters on how the flow is controlled. Due to seeing that and my personal experience now... I recommend against using Bosch filters. I'll see what the Wix looks like when I change the oil. If anyone is interested I'll follow up (with pictures)

arizbea

I've got 7000 miles on my car and I've had this problem almost from day 1. It's pretty bad though. I live in Texas and it even does it when it's warm... for instance, it was almost 50 degrees this morning and it still does it. It's bad though.... mine will just sputter and sputter for several seconds if I keep the ignition on. I've learned and I just turn it off and turn it back on immediately after the hearing the first sputter and then it starts immediately, no problem. I have not asked the dealer about this yet.

steven6870

iTrader: (1)

It's definitely fueling. I thought about this as well, and it makes logical sense. What it sounds like is there is some fuel left to detonate and start the car, but like you say the pump hiccups, like its sucking vapor, not actual fuel, or maybe less fuel than its supposed to, which causes it to lose idle, and then the pump finally gets fuel, and brings the idle back up. I think the thing that really throws us all for a loop is the sound it actually makes. It does not sound like the car is losing fuel pressure or is starved for fuel, IMO it sounds like the flywheel hitting the edge of the starter(starter wheel housing), which has happened on a car I was working on, in which the guy shattered the tranny, and a piece of the clutch hit the edge of the starter. I had to grind it down some so the flywheel would not hit it that edge any more.

But these LNF's are tricky little *******, and make a ton of weird noises. I'm guessing that "card in the bike spoke" sound is just that click noise the high pressure fuel pump makes, just rapidly sped up?

With all the noises the LNF makes, I am only going to start getting worried, when it actually sounds like a normal engine...

Zander916

I was thinking about this more also and sticking with my same theory it could be the regulator that makes the noise, not the pump. As it's trying to deal with sudden drops in pressure, perhaps many times a second and causes it to open/close rapidly. Just a thought...

You still might have winter blend gas though which just behaves differently it sounds like. If we don't come up with a definite solution I think it might be a good idea to bring this thread back from the dead come summer time and see if we've all noticed it stop acting up.

Even better if we could figure out a date when they switch and stop putting winter blended gas in the tanks.

Terminator2

That is a lean condition causing the sputter. The in tank electric fuel pump is probably going bad or you are not turning the key to the run postion and leaving it there for a second or two. The fuel system needs to prime before you start it.

Zander916

I've tried that, no go.

Check out the vid in post #19... you'll see exactly what we're talking about. The guy even let the system pressure up before trying to start it in the video too.

oopsitouchedmyself

iTrader: (2)

my car has been sputtering and not even being driveable when it's been cold out till i let it warm up. i mean, it's like it doesn't even want to get up to 20mph. it misses and sputters and throws misfire codes. then once it warms up it's fine. and i'm on stock tune now.

steven6870

iTrader: (1)

You know you're always supposed to let the car warm up before driving, even when its hot outside, right? I have never driven a car without letting it warm up. I always get a kick out of people when they have car trouble, and you see how they never maintain the car, let it warm up, or take care of their car in general, then they get all pissy and wonder why their car is fubared. (Not saying this is you, just saying...) But then again, I get so pissed when my car messes up, even though I am meticulous about maintenance, and proper care, but others who treat their car like dog ****, never have 1 single issue...grrrrrr.