If it isn't one thing, it's another....
04-04-2005, 05:34 AM
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If it isn't one thing, it's another....
<a href="https://forums.audiworld.com/s4s6/msgs/58398.phtml">The fuel pump problem that wasn't</a>
A week ago or so I posted about my "engine stumbling" problem, which my tech friend had initially diagnosed as a faulty fuel pump. So I ordered a replacement pump, purchased a Bentley manual and set aside some time this weekend to replace the pump. I chose to do the pump swap yesterday, because it was raining all weekend and it wasn't until Sunday afternoon that the rain would let up for a couple of hours and allow me to get started. Before I actually began working, I had to put my car in neutral and push it in a more convenient location. While sitting in the driver's seat, I decided to try to start it up, just for the hell of it... and it started right up.
The car has been running fine since yesterday, and I guess it wasn't my fuel pump after all. Since I had been at the end of that tank of fuel, a friend of mine suggested that I may have sucked up something solid/foul at the bottom of the tank, which had caused my car to stumble and shut off. Another idea which was floated around was the notion that perhaps one of the electrical/ignition systems came into contact with water/condensation last Saturday, which prevented the car from running correctly. (The fact that last Saturday was a beautiful, warm, sunny and dry day is a little problematic here.. but what do I know.)
But then again, it could be something entirely unrelated. <b>Are there any systems which could shut down or fail once they are hot, but "fix themselves" after a proper cool-down?</b> I know, this sounds silly... but I'm struggling to find a reason why my car was not running last weekend, but somehow suddenly runs fine this weekend.
<b>A funny (<i>it's actually a bit sad and annoying</i>) thing happened while my car sat for a week</b>... I developed a pathological shudder/vibration whenever the brakes are applied. This problem was <b>not</b> present prior to the "stumbling" incident, but I can't imagine that they'd be related (but at the same time, what do I know). The vibration/shuddering isn't really present until I get on the brakes, and becomes much more violent the harder I apply the brakes. <b>Could one's rotors just fall apart while the car sits in one spot for a week?</b> It doesn't make sense. I tried taking it out for a nice warm-up run, and attempted to clear the thin layer of oxidation which had formed on the rotor surface during the last week, assuming it was just some sort of temporary issue that would clear itself up after the rotors/pads/fluid had had the chance to warm up a bit. No dice. Can stuff like this just develop while the car sits around for a week?
The To-Do list for Spring 2005 is growing every day. I need a second job!
A week ago or so I posted about my "engine stumbling" problem, which my tech friend had initially diagnosed as a faulty fuel pump. So I ordered a replacement pump, purchased a Bentley manual and set aside some time this weekend to replace the pump. I chose to do the pump swap yesterday, because it was raining all weekend and it wasn't until Sunday afternoon that the rain would let up for a couple of hours and allow me to get started. Before I actually began working, I had to put my car in neutral and push it in a more convenient location. While sitting in the driver's seat, I decided to try to start it up, just for the hell of it... and it started right up.
The car has been running fine since yesterday, and I guess it wasn't my fuel pump after all. Since I had been at the end of that tank of fuel, a friend of mine suggested that I may have sucked up something solid/foul at the bottom of the tank, which had caused my car to stumble and shut off. Another idea which was floated around was the notion that perhaps one of the electrical/ignition systems came into contact with water/condensation last Saturday, which prevented the car from running correctly. (The fact that last Saturday was a beautiful, warm, sunny and dry day is a little problematic here.. but what do I know.)
But then again, it could be something entirely unrelated. <b>Are there any systems which could shut down or fail once they are hot, but "fix themselves" after a proper cool-down?</b> I know, this sounds silly... but I'm struggling to find a reason why my car was not running last weekend, but somehow suddenly runs fine this weekend.
<b>A funny (<i>it's actually a bit sad and annoying</i>) thing happened while my car sat for a week</b>... I developed a pathological shudder/vibration whenever the brakes are applied. This problem was <b>not</b> present prior to the "stumbling" incident, but I can't imagine that they'd be related (but at the same time, what do I know). The vibration/shuddering isn't really present until I get on the brakes, and becomes much more violent the harder I apply the brakes. <b>Could one's rotors just fall apart while the car sits in one spot for a week?</b> It doesn't make sense. I tried taking it out for a nice warm-up run, and attempted to clear the thin layer of oxidation which had formed on the rotor surface during the last week, assuming it was just some sort of temporary issue that would clear itself up after the rotors/pads/fluid had had the chance to warm up a bit. No dice. Can stuff like this just develop while the car sits around for a week?
The To-Do list for Spring 2005 is growing every day. I need a second job!
04-04-2005, 05:49 AM
#2
"Are there any systems which could shut down or fail once they are hot, but 'fix themselves' ..."
"...after a proper cool-down?"
Yep, fuel pump could do this.
A comment on the "sucked up something foul" theory:
I hear this suggested as a possible problem all the time...but I'm not sure why. By design, the fuel pump draws from the bottom of the tank all the time. Maybe this theory came into being because the fuel tank is more likely to fail when the tank is near empty because it is not submerged in the gas so it runs hotter.
Yep, fuel pump could do this.
A comment on the "sucked up something foul" theory:
I hear this suggested as a possible problem all the time...but I'm not sure why. By design, the fuel pump draws from the bottom of the tank all the time. Maybe this theory came into being because the fuel tank is more likely to fail when the tank is near empty because it is not submerged in the gas so it runs hotter.
04-04-2005, 06:08 AM
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2nd, fuel pumps are one of those wierd electrical things
they may stumble once and never fail again. or they they may act up a few times before they fail. Or they act up once, act fine, then just die one day. There is no telling with electrical stuff
04-04-2005, 06:09 AM
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Hmm.. that's interesting.
I'll try to keep no less than a 1/4-tank of fuel from now on... and I hope it'll help prevent this sort of thing in the future.
I now have a new fuel pump and filter at home... I guess I'll have them swapped in during my next major service.
What do you think about the brake problem? Could something like that simply develop out of nowhere during a one-week period of sitting around...?
I now have a new fuel pump and filter at home... I guess I'll have them swapped in during my next major service.
What do you think about the brake problem? Could something like that simply develop out of nowhere during a one-week period of sitting around...?
04-04-2005, 06:23 AM
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Unfortunately your no start problem will definately manifest....
itself again. It may be tommorrow or it could be three months from now. Especially if the problem is the pump. Failing fuel pumps especially like tow truck rides. 90% of the time they will fix themselves before they get to the shop. I am not saying your pump is bad I am just saying it is highly unlikely it is fixed or it may not be the problem at all. Keep a short leash on her till you are sure the problem is solved. The rotors were warped before you probably just did'nt notice. Good luck and you might want to get AAA.
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04-04-2005, 06:34 AM
#8
Second. If you want to isolate the shudder front to rear,
hold the button down on the e brake and pull it up while driving. If you feel vibration, the rears are the problem, no vibration then the problem is in front.