I realize the SOTP dyno isn't the most accurate, but I am convinced I feel a relationship between gas tank level and power smoothness. When on 'E' it runs like a dog and after topping off at the tank I see a huge difference. Could my fuel pump be starting to go? Maybe the extra pressure of being submerged in more fuel helps it out? I'm just throwing out guesses...

 

maybe the fact that the pump isnt sucking 20 year old sediment??

 

His truck is only 19 years old

 

maybe after filling up you only perceive that your truck's got more umph, cause then your adrenaline get's pumping as you heart rate goes up after you realize that you're litterally burning $30 every time you stop at the pump every week


or is that only me...

 

...

 

maybe your pump is on its way out?

 

Actually my '94 Camry felt noticeably better after filling up on 93 octane. I knew it wouldn't do anything but I didn't want to have to go back in and get my change so I got premium.

 

Same here. I notice a difference too. It idles much better with a full tank.

And I know it's not that adrenaline pumping making me think it's running better, because where I fill up my tank I usually only spend around $15, which is really a relief and I'm surprised at how cheap it is to fill up.

 

x2 on sediment or junk in the tank getting on the "fuel pump sock"

 

$30 would be friggin great... More like 40-50 here... If I off road that weekend its more like x2 a week. Seems minor thoe compared to the cost of repairs thoe. XD

 

i notice the same thing in my runner bun only below a 1/4 tank if i put just enough to get above the 1/4 tank mark it seems to have more power but then when it dips below that i lose some again could it still be sediment if its that exact???

 

maybe...
when the fuel level is low, the heat absorbed by the fuel while in the lines near the engine isn't able to be radiated out thus lowering the density of the fuel and affecting the air/fuel ratio... and when the tank is full, there is less heat soaking of the fuel and more exposure to the tank walls allowing heat to be radiated out, resulting in a more dense fuel mixture?
or maybe not....

 

that would sound great but i havent heard of everyone having the same problem if that were the case i would think i would have heard about it before..... actually before this thread i thought it was just me....

 

It makes no sense. It should be a little peppier with almost empty tank cause you don't have all that fuel to haul around.

 

with a perfectly smooth tank, with brand new gas, it would be. but thats impossible.

 

i tried 110 oct. we have ONE pump at ONE 76 station in ALL of san jose that does 110. its advertised as 100 but i have seen the number on the drums it comes in.

it was pretty nice. i couldnt really FEEL a difference per se.

but it idled smoother and imho ran better than the 89oct. my truck is used to.

maybe it just burned some of the gunk off my valves.

oh well. that pump got taken out.

gotta wait for the VP RACING fuel station down the street to finish getting built.

 

when the tank is low the pump heats up really hot causeing the fuel to heat up like abe said and when there a full tank it covers the pump makeing it run alot cooler


try this one on for size drain your rad of all the coolant drive you truck or car it runs really hot and almost overheats right

but then if thers coolant in the rad and everything she runs cooler right same thing with the fuel pump the fuel in the tank is the pumps coolant!

 

sounds good to me

although that is true, as ironic as it sounds, that the gas is the fuel pump's cooling

 

oh my god, norbert was right???

 

maybe the gas is fresher and less degraded then after is been sloshing around in your tank for a week. I once had a 89 mustang that would run really bad when hot out, but when ever you filled it up it ran great for awhile. It could have been the temp of the gas coming out of the underground tanks or it could have been a volume issue either way it made a huge difference. Shortly after this period of time the fuel pump failed completely.