Do you all experience better acceleration with more fuel?
05-03-2004, 12:47 PM
#1
Guest
Posts: n/a
Do you all experience better acceleration with more fuel?
I know this will sound very stupid, because it ought to be the other way around, BUT lately I've been noticing better acceleration with more fuel in my tank. It is very weird. I wonder if any of you ever felt the same thing.
First, I often drive till my reserve light comes on. I'm one of those people who never keeps the tank more than half full. For some time now, I noticed that when I have 1/4 tank of gas I feel that my car accelerates worse than when I have 1/2 tank or so.
Second, I'm thinking it may be the fuel pump. Maybe fuel injectors? I get no ECU codes though. Isn't it true that the less gas you have and you drive hard, then you are putting enormous stress on the fuel pump?
Third, I had something very unusual happen a couple times recently. While driving 100+ mph, my car cut off fuel all of a sudden - at least that's what it felt like. I know it has nothing to do with the limiter because I've gone up to 143 mph before and speeds alike with no cut-offs whatsoever. After a while, I realized that this cut-off of some sort (during which I cannot accelerate for 5 seconds or so) only happened when the tank was 1/4 or less full.
Any suggestions????
First, I often drive till my reserve light comes on. I'm one of those people who never keeps the tank more than half full. For some time now, I noticed that when I have 1/4 tank of gas I feel that my car accelerates worse than when I have 1/2 tank or so.
Second, I'm thinking it may be the fuel pump. Maybe fuel injectors? I get no ECU codes though. Isn't it true that the less gas you have and you drive hard, then you are putting enormous stress on the fuel pump?
Third, I had something very unusual happen a couple times recently. While driving 100+ mph, my car cut off fuel all of a sudden - at least that's what it felt like. I know it has nothing to do with the limiter because I've gone up to 143 mph before and speeds alike with no cut-offs whatsoever. After a while, I realized that this cut-off of some sort (during which I cannot accelerate for 5 seconds or so) only happened when the tank was 1/4 or less full.
Any suggestions????
05-03-2004, 07:31 PM
#3
Supporting Maxima.org Member
Join Date: Sep 2003
Posts: 1,004
All I can think of is the fuel pump is working too hard when the tank is too empty. I'm thinking with a fuller tank there is more natural boost (pressure) feeding the gas to the injectors. I'm only speculating.
05-07-2004, 01:19 PM
#8
Well, after owning my max for about 5 months now, i know exactly what your talkng about...
My reasoning was simply the "brains" of the max...i know when i have about a quarter tank left, it runs normal, but as soon as i get under that quarter tank line, it changes the way it runs...My reasoning was this....
the ECU in newer cars adjusts itself to MANY things, our driving habits, weather (like air quality), heat, or cold....(correct me if im wrong on this)
with these things in mind wouldnt it only make sense that our ECUs are programed to change the running of the car to preserve fuel? I have also noticed that not just the acceleration of the car is affected but also the sensitivity to throttle adjustment is effected as well.. IMO i would guess its the ECU working to concerve your fuel to get to the gas station...also if you pay attention that last quarter tank of gas lasts a bit longer than the first TOP quarter tank line...
What do you guys think on this "theory"?
My reasoning was simply the "brains" of the max...i know when i have about a quarter tank left, it runs normal, but as soon as i get under that quarter tank line, it changes the way it runs...My reasoning was this....
the ECU in newer cars adjusts itself to MANY things, our driving habits, weather (like air quality), heat, or cold....(correct me if im wrong on this)
with these things in mind wouldnt it only make sense that our ECUs are programed to change the running of the car to preserve fuel? I have also noticed that not just the acceleration of the car is affected but also the sensitivity to throttle adjustment is effected as well.. IMO i would guess its the ECU working to concerve your fuel to get to the gas station...also if you pay attention that last quarter tank of gas lasts a bit longer than the first TOP quarter tank line...
What do you guys think on this "theory"?
)
05-07-2004, 01:49 PM
#11
I have a feeling it is the ECU. There is a 3.5 mile long bridge right around the corner from me and I used to go there to run all of my cars. I ran my max after I had it about a week. To my dismay it felt like I hit a brick wall at about 120 despite being well below redline. I began to wonder if I hade a limiter and my speedo was off (thus limited at 120). I was racing a modded integra one night and pulled right up to about 140. I scratched my head. Managed several more runs past 120. Then one day i hit a wall again. I eventually found that with little gas my max will not go past 120ish. I have run across the bridge and run errands then come home all within a few hours and had the cut on the way back but not on my first past. I have to believe it is the ECU. I have no other signs of fuel issues.
05-07-2004, 04:18 PM
#12
Originally Posted by Liquid_pjear
I have a feeling it is the ECU. There is a 3.5 mile long bridge right around the corner from me and I used to go there to run all of my cars. I ran my max after I had it about a week. To my dismay it felt like I hit a brick wall at about 120 despite being well below redline. I began to wonder if I hade a limiter and my speedo was off (thus limited at 120). I was racing a modded integra one night and pulled right up to about 140. I scratched my head. Managed several more runs past 120. Then one day i hit a wall again. I eventually found that with little gas my max will not go past 120ish. I have run across the bridge and run errands then come home all within a few hours and had the cut on the way back but not on my first past. I have to believe it is the ECU. I have no other signs of fuel issues.
05-07-2004, 04:30 PM
#13
Member
Join Date: May 2004
Posts: 98
I get the same damn thing. I pulled out of the gas station after filling my tank to the top and it just seemed to get up and go a lot more. I usually drive with less than 1/2 a tank and I can definetley feel the difference. Not sure what it is, but its kinda cool. As for the fuel cutoff thing, Ive never heard of that. Ive driven my car above 125+ with no cutoff, just a slight vibration. I also notice that fuel seems to go a lot quicker from a full tank to a 1/2 a tank, and lasts longer from 1/4 a tank to empty, but maybe its just me. I also get a slight vibration when I hit 80 mph, no less, no more. I just replaced the ball joints, struts, and tires, and can;t figure out what it is. Its not too bad, just kind of annoying. Any suggestions?
05-07-2004, 05:09 PM
#15
Guest
Posts: n/a
I get the same damn thing. I pulled out of the gas station after filling my tank to the top and it just seemed to get up and go a lot more. I usually drive with less than 1/2 a tank and I can definetley feel the difference. Not sure what it is, but its kinda cool. As for the fuel cutoff thing, Ive never heard of that. Ive driven my car above 125+ with no cutoff, just a slight vibration. I also notice that fuel seems to go a lot quicker from a full tank to a 1/2 a tank, and lasts longer from 1/4 a tank to empty, but maybe its just me. I also get a slight vibration when I hit 80 mph, no less, no more. I just replaced the ball joints, struts, and tires, and can;t figure out what it is. Its not too bad, just kind of annoying. Any suggestions?
Same here. When I try to top out when empty, my car cuts off at around 110... With a little more than a quarter tank, it will climb to 130 ish..
I have a feeling it is the ECU. There is a 3.5 mile long bridge right around the corner from me and I used to go there to run all of my cars. I ran my max after I had it about a week. To my dismay it felt like I hit a brick wall at about 120 despite being well below redline. I began to wonder if I hade a limiter and my speedo was off (thus limited at 120). I was racing a modded integra one night and pulled right up to about 140. I scratched my head. Managed several more runs past 120. Then one day i hit a wall again. I eventually found that with little gas my max will not go past 120ish. I have run across the bridge and run errands then come home all within a few hours and had the cut on the way back but not on my first past. I have to believe it is the ECU. I have no other signs of fuel issues.
OMG, Thank you all
for responding. 
Now I know I'm not alone and from what I see it is rather normal. ORG is a kick A$$ place after all because without it I would have never known this, causing me to probably swap/replace unnecessary parts. Again, big thanks to all you guys!
Same here. When I try to top out when empty, my car cuts off at around 110... With a little more than a quarter tank, it will climb to 130 ish..
I have a feeling it is the ECU. There is a 3.5 mile long bridge right around the corner from me and I used to go there to run all of my cars. I ran my max after I had it about a week. To my dismay it felt like I hit a brick wall at about 120 despite being well below redline. I began to wonder if I hade a limiter and my speedo was off (thus limited at 120). I was racing a modded integra one night and pulled right up to about 140. I scratched my head. Managed several more runs past 120. Then one day i hit a wall again. I eventually found that with little gas my max will not go past 120ish. I have run across the bridge and run errands then come home all within a few hours and had the cut on the way back but not on my first past. I have to believe it is the ECU. I have no other signs of fuel issues.
OMG, Thank you all
for responding. Now I know I'm not alone and from what I see it is rather normal. ORG is a kick A$$ place after all because without it I would have never known this, causing me to probably swap/replace unnecessary parts. Again, big thanks to all you guys!
05-07-2004, 08:30 PM
#18
Somethin gi sup cause i was driving to the gast station just now and on the way there with 1/4 tank it was sluggish and even shifted a lil hard (AT) but on the way back it seriously had more of a punch and was smoother shifting....this was not in my head...i have noticed it for about a year now....
I keep track of my MPG everytime i fill up and notice if I fill at or more then 1/4 i get about 21-22 mpg yet if I let it go til the light comes on i average closer to 24......definately ECU in safe mode or GAS SAVE MODE.....or something cause there is defiantely a change....
To figure ur MPG just reset the gauge everytime you fill up....look at how much you put in gallon wise...today mine was 307.6 miles and i filled 14.3 gallons
05/07
307.6/14.3 = 21.51 = filled a lil above 1/4 work and school...not much highway
04/30
345.8/14.8 = 23.36 = filled when light came on.......
thats like 2 extra Mpg and with 15 gallons that is about 30 miles extra everytime u fill up......something to consider..........
I keep track of my MPG everytime i fill up and notice if I fill at or more then 1/4 i get about 21-22 mpg yet if I let it go til the light comes on i average closer to 24......definately ECU in safe mode or GAS SAVE MODE.....or something cause there is defiantely a change....
To figure ur MPG just reset the gauge everytime you fill up....look at how much you put in gallon wise...today mine was 307.6 miles and i filled 14.3 gallons
05/07
307.6/14.3 = 21.51 = filled a lil above 1/4 work and school...not much highway
04/30
345.8/14.8 = 23.36 = filled when light came on.......
thats like 2 extra Mpg and with 15 gallons that is about 30 miles extra everytime u fill up......something to consider..........
05-07-2004, 10:13 PM
#21
Banned
Join Date: Jan 2004
Posts: 114
Originally Posted by BOSS
I know this will sound very stupid, because it ought to be the other way around, BUT lately I've been noticing better acceleration with more fuel in my tank. It is very weird. I wonder if any of you ever felt the same thing.
First, I often drive till my reserve light comes on. I'm one of those people who never keeps the tank more than half full. For some time now, I noticed that when I have 1/4 tank of gas I feel that my car accelerates worse than when I have 1/2 tank or so.
Second, I'm thinking it may be the fuel pump. Maybe fuel injectors? I get no ECU codes though. Isn't it true that the less gas you have and you drive hard, then you are putting enormous stress on the fuel pump?
Third, I had something very unusual happen a couple times recently. While driving 100+ mph, my car cut off fuel all of a sudden - at least that's what it felt like. I know it has nothing to do with the limiter because I've gone up to 143 mph before and speeds alike with no cut-offs whatsoever. After a while, I realized that this cut-off of some sort (during which I cannot accelerate for 5 seconds or so) only happened when the tank was 1/4 or less full.
Any suggestions????
First, I often drive till my reserve light comes on. I'm one of those people who never keeps the tank more than half full. For some time now, I noticed that when I have 1/4 tank of gas I feel that my car accelerates worse than when I have 1/2 tank or so.
Second, I'm thinking it may be the fuel pump. Maybe fuel injectors? I get no ECU codes though. Isn't it true that the less gas you have and you drive hard, then you are putting enormous stress on the fuel pump?
Third, I had something very unusual happen a couple times recently. While driving 100+ mph, my car cut off fuel all of a sudden - at least that's what it felt like. I know it has nothing to do with the limiter because I've gone up to 143 mph before and speeds alike with no cut-offs whatsoever. After a while, I realized that this cut-off of some sort (during which I cannot accelerate for 5 seconds or so) only happened when the tank was 1/4 or less full.
Any suggestions????
had the same problem, didnt check my fuel level at the time? but at 30mph driving id get this "fuel shutoff" that lasted 5 seconds and would stall unless i floored it.. making it jerk when it came back on...
sometimes the fuel pump gets weird and "sticks" i also notice when my car is started and its still cold it runs wayy more tourqe.
i need boost.
05-07-2004, 10:54 PM
#22
Member
Join Date: May 2003
Posts: 71
Hey thanks for bringing it up, seems like something that was on the back of peoples minds, including mine. I notice a lag after fueling the tank to full... However, if I've been driving on fumes for a while and pull to the gas station to put in 5 bucks, I usually pull off and start to feel a little more out of the car.
05-08-2004, 04:39 PM
#23
I've had the same problem with my 95.
I thought I had it fixed by putting some grease on the fuel cap. It seems like the EVAP system is the cause. However, I just found out my air temp sensor is bad. So, after getting rid of that problem on an empty tank I get the same performance as I get on a full tank. There is no longer any difference.
I can't logically figure how these two are connected unless there is some EVAP and air temp correlation. Who knows, maybe it runds leaner on a full tank bc less vapor?
I thought I had it fixed by putting some grease on the fuel cap. It seems like the EVAP system is the cause. However, I just found out my air temp sensor is bad. So, after getting rid of that problem on an empty tank I get the same performance as I get on a full tank. There is no longer any difference.
I can't logically figure how these two are connected unless there is some EVAP and air temp correlation. Who knows, maybe it runds leaner on a full tank bc less vapor?
05-08-2004, 07:25 PM
#24
Senior Member
Join Date: Dec 2003
Posts: 501
Sorry you guys but no. Run your car at the track 5 times with a full tank. Come back next weekend and run you car 5 more with an eight of a tank. you will be about one tenth quicker. The equivlant to about half a car maybe a little more. Gas weighs something like 7 pounds a gallon. The difrence from an eight of a tank and a full tank is like 15 gallons. Or 105 pounds. And it's about 100 pounds for a tenth in the quater mile. Not much diffrence but definatley not faster full. The computer maks no adjustments for low gas, except the extra electrical system drag from the fuel light
05-08-2004, 09:02 PM
#26
Senior Member
Join Date: Jun 2002
Posts: 204
I wont say for sure, but I seem to have the same quicker on full feeling. 2 theories here.
1st. Its all in yer head... full tank= more rear weight= more rear suspension compression on accelleration = that rocketship feeling
2nd. Right after filling up you have relatively COLD fuel in your tank, having just been underground for some period of time. Unlike the fuel thats been in your tank sittin in the hot Texas sun for hours on end. If Im not mistaken liquids do expand and contract relative to temperature. Could colder fuel = denser fuel?
Im curious if anyone up north, say Michigan, Newyork, Penisilvania,etc notice any difference seasonally when your tanks are damn cold!
1st. Its all in yer head... full tank= more rear weight= more rear suspension compression on accelleration = that rocketship feeling
2nd. Right after filling up you have relatively COLD fuel in your tank, having just been underground for some period of time. Unlike the fuel thats been in your tank sittin in the hot Texas sun for hours on end. If Im not mistaken liquids do expand and contract relative to temperature. Could colder fuel = denser fuel?
Im curious if anyone up north, say Michigan, Newyork, Penisilvania,etc notice any difference seasonally when your tanks are damn cold!
05-09-2004, 01:24 AM
#30
Senior Member
Join Date: Dec 2003
Posts: 501
Originally Posted by Big D
No you won't as you'd never get past 100mph in a 1/4 mile run. Also a full tank of gas weighs around 130lbs so you would be .1 sec slower than with a 1/4 tank or around there.
06-13-2010, 03:31 PM
#31
Newbie - Just Registered
Join Date: Apr 2010
Location: bridgeport connecticut
Posts: 3
I agree with guttermouf. fuel that has been underground is colder and denser which equates to more horsepower when ignited. I feel the same way as you all when i put more juice in the tank. Cold juice taste better than warm juice.
06-13-2010, 03:55 PM
#32
[quote=I also notice that fuel seems to go a lot quicker from a full tank to a 1/2 a tank, and lasts longer from 1/4 a tank to empty[/quote]
Really? I can get 200 miles on my car from full to half and I only get another 150 for the last half
Really? I can get 200 miles on my car from full to half and I only get another 150 for the last half
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