i've had my car for 50k plus miles and i think this just happened to me for the first time the other night. i've run my car to over 30 miles after the light came on and never had any problems like this. light came on and i was on the way to the gas station up a steep hill and car started bucking hard couldn't make it up the hill almost. there was also what sounded like a rumbling sound coming from the back of the car. anyone experience weird noises like that with this issue?

 

I had both my FUEL TANK and Fuel pump changed. Apparently the tank was deformed. It was done 2 years ago with low mileage under warranty!
You should NEVER have less than 1/3 of gas in your tank, 1/2 tank in winter time.

 

Just to let ya'll know, I usually fill up when the yellow light comes on.

 

Yes, getting your fuel filter dirtier faster is not a good thing... For those that don't do any preventative maintenance on their cars. I would hope that all of the enthusiasts on this site replace their filters on time or before. I do.

I know what condensation is but you must not know what the dew point is. Your gas must be COLDER than the outside air in order for water to condense. Your logic is flawed.

I stand by my original information. It is correct.

BP

 

Well i guess my stuck bobber problem is actually helpful for another problem, my gas light turns on when there is really 1/4 tank and only goes the the 3/4 bar when full. Due to me bobber problem i only burn 13 gallons in between fill ups leaving a few to cool down the pump. A problem helping another problem, thats a mazda.

 

I just never really run my tank below 1/4 for the simple fact that it does have the possibility to strain the fuel pump. Do that enough times...you end up with a defective fuel pump.

 

yep I learned this the hard way... huge repair bill

 

2006 mazda 6s, this just started happening to me a couple months ago. I actually had a check engine light pop on recently and I assumed it was related, but after this thread I'm thinking maybe my gas cap was just loose (was planning on taking car in to a mechanic this week to get it all sorted out and get an estimate). 78k miles on the car so I believe I am screwed unfortunately on the warranty. Bummer

 

I forgot to post an update. I fixed my "out of gas at 1/4 tank" problem by replacing the fuel pump module. The fuel pump was bad. The sock was barely dirty so that wasn't the problem. My car only has 27k miles.

I'm guessing that the noises that I said I heard before was actually the fuel pump overheating and binding up. I bought a set of fuel line couplings and I'm going to do a fuel pressure test with both the new and old modules next spring. (My '06 doesn't have a fuel pressure test port.)

I'm also planning on fitting a 190lph Walbro in place of the stock piece of crap. Possibly a adjustable fuel pressure regulator too.

BP

 

how you plan to adapt the FPR in? GL on the Walbro, Haven't seen anyone successfully do it yet....

 

I'm thinking of re-plumbing the fuel pump to output full pressure through the stock fitting. Then I'll mount the AFPR on top of the fuel pump module cover and use a bulkhead fitting to make a return feed back to the inside of the module. If any of that makes sense.

I don't think that the Walbro will be that tough. As long as it isn't larger in diameter by more than 3/16" than the stock pump, I should be able to make it fit. I need to get one ordered and start playing with it.

The other interesting thing about running a AFPR is that the PCM doesn't have a fuel pressure sensor. That means that if the pressure is adjusted, it will richen up or lean out the mixture. Perfect for someone with basic mods that just needs to tweak things a little. Just like on my Contour.

BP

 

be sure to make a thread about it. will be interested to see.

 

Same bucking and stuttering happened to me. I have a 2004 6S with 208000K.

Was low on gas (the light came on/off a few times, but was off when it happened) and went up a pretty steep hill. Merged onto another road going uphill again when the bucking started. Barely made it to the top where I pulled into a parking lot.

The "AT" light was on, so I thought it was the tranny. Turned the car off and after restarting the light was gone.

Decided to drive it home and if I kept the car in 3rd or 4th gear it ran OK, but as soon as I had to slow down an accelerate the bucking started again.

Got it home and let the car sit a few hours. Put $10 gas and drove it around and had no problems.

After that I never let the tank go below 1/4 and haven't had any problems since.

This thread really helps because if it were a tranny problem then I would seriously considering selling it.

Thanks Twitmer and everybody else.

 

Everybody in this thread is saying, "Well I just don't run it down under 1/4 of a tank."

You still have a problem. In my car it was more pronounced and I was always getting a check engine light for Lean Off Idle. My thoughts are that the fuel pump is weak all the time. Only when you get to 1/4 tank does it completely fail. When above 1/4 tanks it's still not delivering as much fuel as it should when it should.

The lean spikes will only accelerate engine wear and damage the pre-cats.

BP

 

When I had my 2003, I experienced this problem once, but it was at the track, under 1/8-tank, while taking an extreme right-hander. After that, I never let it get below 1/4-tank at the track. But, I never had the issue on the road and I regularly ran it below E without issue, so this thread has been intriguing to read. I wonder if the issue only starts occurring after the pump reaches a certain age?

 

I'm convinced that it's a cheap, poorly designed pump. Mine started showing signs of failure around 10k miles.

No modern fuel pump should last less than 100k miles.

BP

 

+1 agreed.

 

Same issues here. 2006 Mazda6s. Band-Aid (fill up at 0.25 tank) to mask a huge disease (faulty fuel pump). I'm surprised that this thread has gone on for so long and no one has performed a DIY??? I think I've read one Remove/Replace action, but it was through the dealership and under warranty.

 

There's not really much to it. Remove seat, unplug old fuel pump, unscrew ring, put in new pump.

I did take a bunch of pics when I did mine so I could post one up.

BP

 

06 v6 60k miles, 12-14 gallon fillups every time and now im starting to stall out on hills. . Does anyone have a link on how to change the fuel pump? Shop wants $600, The pump goes for 150 on ebay new.

 

thanks!

I have a 2006 Mazda 6s with just under 60k miles. This exact problem started a couple of months ago - Took me awhile to figure out that it was tied to the tank being below 1/4 tank and going uphill or around curves like off ramps. Had it in to the dealer twice and even mentioned that it seemed worse when the tank was low and they had no clue. Finally took it in today with about 1/8 of a tank and drove with the mechanic. After half an hour of checking, he Said I need a new fuel pump - $800. Ouch

 

@steeveo I've been filling mine up when it hits 1/4 tank for almost three years and it hasn't gotten any worse.

It's a bit inconvenient at times, but really not bad when compared to paying a dealer $800 or blowing a few hundred $ and some precious weekend time doing it myself.