Engine stalls when tank is less than 1/4 full

chevrolet
trailblazer

#1

GM Customer Service phone line and my local GM dealer can’t find a solution. Trailblazer 2008. This has happened 6 or 8 times.
When fuel tank is 1/4 full or less, decelerating downhill from 50 mph to make a right-hand turn, the engine stalls as I reach the turn. Of course I lose power steering and brakes.

If I stop in that downhill position, the fuel gauge reads ZERO but the Low Fuel light is not showing. Turning the key to restart does not restart the engine but if I roll to a flat piece of road or to an uphill position, the engine starts immediately on turning the key. The fuel gauge continues to show ZERO until I turn off the ignition completely and restart. Then the fuel gauge immediately returns to indicate 1/4 full.

No warning lights of any kind show on the dash.

There is no question of the gauge showing a false 1/4 indication when the tank is actually empty, since I can drive for 30 miles after the incident while the gauge slowly drops lower until I fill up again with gas.

SOMETHING tells the engine it has no gas so it stops. No stutter or indication of fuel starvation. Simply an engine shut-off.

I tried to reproduce the effect immediately after it had happened by turning the car round and retracing the route, but it did not happen a second time at that location, but it did repeat a few hours later at another intersection.


#2

The 2008 Trailblazer gas tank has a really weird shape, long and shallow, mounted longitudinally with two levels, the higher being to the rear of the vehicle and the fuel pump being mounted above the higher level. Decelerating while descending a steep hill could, IMHO cause the fuel below the pump to move to the deeper area at the front of the tank and cause loss of fuel supply. There should be baffles in the tank, but those WILL allow flow between sections, and prolonged braking going downhill could allow such movement of the fuel. The baffles are only designed to mitigate fuel migration, not totally prevent it.

I tried to post a photo of the tank and its installation, but I’m technically challenged and was unable to. I suggest you google the image.

I think the solution is to simply keep more gas in the tank.


#3

Agreed with the same mountainbike about the cause and solution.

My Lincoln has a long narrow, shallow tank that is mounted transversely. I discovered the hard way one time the downside to parking with both passenger side wheels higher than the two drivers side wheels while only having a couple of gallons in the tank.

The pump is mounted on the right side of the tank, the 2 gallons of fuel sloshed to the opposite side, and I was left with a no-start car. Off to the gas station on foot with a 2 gallon jug…


#4

Another consideration is to avoid hilly areas with gas stations farther apart. Maybe that’s why we don’t see as many of these in Maine. Still, it would bother me enough with the loss of power brakes and steering to either consider moving to Texas or change vehicles or keep contacting GM for some bulletin/suggestion for a solution; like avoiding Maine. Has the vehicle always done this or is it something new ? Maybe it’s more susceptible with a partially clogged filter or other problem. This may not be the only causal factor. It may be something(s) else in addition to tank that is exacerbating the situation.


#5
There is no question of the gauge showing a false 1/4 indication when the tank is actually empty,

Sorry , but if you know this, why keep letting the fuel get that low? You say that this happens every time, so why would you expect different results each time? I agree with TSM, just come to the realization that for your truck 1/4 tank is empty and get fuel.


#6

GM has issued a Technical Service Bulletin #05-00-89-078B that addresses the erratic fuel gauge.

The problem stems from the sulfur in gasoline accumulating on fuel system components. This can effect the fuel pump and the sending unit for the gas gauge.

GM recommends that their GM Fuel System Cleaner P/N 88861011 be added to the gas tank to remove these sulfur deposits from the fuel system components.

Worth a shot!

Tester


#7

As a rule I just don’t ever let my cars get below 1/2 tank. I just prefer to be ready to move out any time day or night without worrying about getting gas. Storms hit and knock out power which can shut the gas pumps down. Last year my son was without power for five days. I just prefer to be ready for contingencies.