Good post. My Harley Supercharged F150 has this issue. Most of the fuel sent to the engine goes back to the tank. A little warmer each time. I have a couple of bad pumps in the tank that loose pressure when warm. Truck runs great at 30 degrees, full power. When it is 80-90 degrees out, falls on it's face and goes lean. And the amount of fuel in the tank makes a huge difference.
Matryx boost fuel pump
- Thread starter snosfun
- Start date
All my issues were with 50%+ in the tank, had a least 6 gallons in there when I got the low fuel pressure limit warning
Frequently running low on fuel is harder on the fuel pump, and maybe there's some triggering event if a tank is run too low before the pump has "settled in," but even that doesn't exonerate Polaris. In a properly designed system, running around with only a few gallons may shorten the life of the pump(s), but not drastically so; how many people drive their cars around with a quarter tank and only put a couple gallons in at a time? That'd be a lot, and it doesn't seem to be an issue with most cars. Running the tank down to a couple gallons (or less) is pretty standard stuff, especially on mountain sleds; Poo's product testing team would have been foolish not to take a couple new sleds and run them around on fumes. If it's not a problem once the pump has broken in, then they should either bench run the pumps to break them in, or at least put a warning in the manual not to run the tank low the first few rides, but it'd be too late for some people on that.
Anyway, hard to say what the defect is: could just be a run of bad pumps, in which case fuel levels and warm gas are red herrings. Could also be a design issue, and "don't run low on gas" is not a fix. You can't blame Polaris because they can't get new pumps fast enough, but they've definitely got a problem on their hands, and I hope they're doing everything possible to find the cause and fix it.
Anyway, hard to say what the defect is: could just be a run of bad pumps, in which case fuel levels and warm gas are red herrings. Could also be a design issue, and "don't run low on gas" is not a fix. You can't blame Polaris because they can't get new pumps fast enough, but they've definitely got a problem on their hands, and I hope they're doing everything possible to find the cause and fix it.
My sled has never had less than half a tank and fuel pump is dying at 250 miles. It’s not the gas levels causing it
I can blame Polaris because it’s obviously a **** design or bad qc with their suppliers. Use cheap parts or don’t test enough and this is what happens.
I can blame Polaris because it’s obviously a **** design or bad qc with their suppliers. Use cheap parts or don’t test enough and this is what happens.
I was told years ago that it's not the low fuel as much as the heat. The fuel cools the pump less fuel less cooling
The fuel that returns to the tank is also warm and if the heat exchanger also heats up the gas the pumps might just run to hot even full. Just a thought .
The fuel that returns to the tank is also warm and if the heat exchanger also heats up the gas the pumps might just run to hot even full. Just a thought .
Heat exchangers have been under tanks for yearssss now. Also there has to be more than just me out there that gets back to their truck on reserve at the end of the day of riding. There is no way a person could pack that much fuel to keep at least half a tank at all times while riding in order to keep your fuel cold. From the pics I have seen and the video from the VOLK guys heat is not an issue, manufacturing is the issue
96 miles, Whining pump and low fuel pressure. Tank has never been under 75% FWIW
Fully agree. My pumps are bad on my truck, otherwise not an issue.
I have also been plagued with the low fuel pressure code coming on. I’ve been dealing with this issue since Christmas-time and it continued to get worse till the problem was so consistent that I had to stop and drop the sled off at dealer this past weekend. Sled is NA pro 165 and has 650 km. This is what I found while riding the sled:
In the morning sled ran great but by the afternoon the sled kept giving me a low fuel pressure light every time I gave full throttle. What I did notice was when the tank had 50% or less fuel and we put cold fuel in the tank the problem would go away and eventually come back. We did this 5 times with the same results.
Is the fuel getting so hot that the sock is getting warm and starting to deform and collapse causing the pump to work harder?which may be why my pump is way louder in the afternoon. Hopefully Polaris has a fix for it soon….
In the morning sled ran great but by the afternoon the sled kept giving me a low fuel pressure light every time I gave full throttle. What I did notice was when the tank had 50% or less fuel and we put cold fuel in the tank the problem would go away and eventually come back. We did this 5 times with the same results.
Is the fuel getting so hot that the sock is getting warm and starting to deform and collapse causing the pump to work harder?which may be why my pump is way louder in the afternoon. Hopefully Polaris has a fix for it soon….
Mine made the loud pump noise 2 rides ago and 4 low fuel pressure codes the same day. Adding gas did nothing to help me. Next ride pump was very loud first thing, only 15 minutes in and full of gas same thing, low fuel codes. Dropped it off at the dealer Tuesday, and on Wednesday it was ready for pickup with a new pump installed.
Damn, good on your dealer... very curious if problem persists after you put some miles on it. Imagine its an identical pump. I just heard back from my dealer and they ran full service bulletin and mine checked out c-clip and o-ring correct, fuel lines ran correct, everything to spec. Sent logs to polaris, waiting to hear back. Last weekend was the first time I saw codes, before that just loud whine later more so later in day. Will also note it was a warmer sunny day, sled stayed around 113-121 never got crazy hot but warm spring like day and I was 26 miles in when codes threw
T
TheBreeze
Well-known member
T
TheBreeze
Well-known member
Have either of you successfully installed the heat mat? Did it install smoothly, and compress enough?
Just got mine in. Going on here in the next couple days . It’s fairly thin so I don’t think there is going to be a problem. It’s actually thinner than the foam that already on there .
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The “hot fuel” theory seems like a stretch to me. Especially considering every brand has run the heat exchangers under the tanks for years and never seen a problem. Secondly, sleds today also run much cooler engine temps. The older axys ran consistently in 130-140 and the new sleds around 110degrees off trail. Kinda of blows me away too that no one has bothered to directly check the fuel temperature at full tank in the morning and 1/2 tank in the afternoon. It would be very easy to do. I just don’t see the fuel getting anywhere close to the 200 degrees it takes to “boil”, as others have blamed this problem on. Some mentioned when the pump started to whine the put “cold fuel” in and it went away. My guess is that any temp fuel would have done the same thing. I just got the first 40 miles on my matryx yesterday. Pump started a very slight whine toward end of the day. Next time I go out I’m definitely measuring my fuel temps throughout the day. Maybe I’ll prove myself wrong. Fun experiment though.
I agree with you. One thing I will say is mine started howling while riding a low snow hill climb type area (sustained high engine speed). Temps still didn’t go crazy.
Yesterday was cold as balls and we were tree riding decent snow. No noise all day.
Temps may play into it but I don’t know if I see a temp pad helping. Leading more toward manufacturing/material defect in the pump
