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When my gas tank gets below 6 gallons and I take a turn like going around a clover leaf on ther interstate exit the engine sputters, and I lose most all my power and it will usually die. I have barely made it home a couple of times. As long as I keep it above 6 gallons I have no problems. Anyone hav an I dea why this happens?

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What kind of vehicle is it? As the fuel gets low in the tank, it sloshes around and the fuel pickup can't reach it. The baffles in the tank may be loose or broken, allowing the fuel to slosh around more than originally allowed.
 

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Jason,

I'm having the same problem in my 91' DeVille. Have to fill her up when she hits 10 gallons. You mentioned the tank unit. I'm assuming the sending unit, but are we really talking about the in-tank fuel pump needing replaced? Does the fuel pump get hot, and that causes the sending unit (with low gas) to malfunction? Or am I rambling? Do I replace the fuel pump or the sending unit?
 

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okay... get under the car and check the wires on the fuel pump. my S10 had some loose wires. it my be a coincidence like it was for me. when you go around a turn fast enough, the force might be enough to cause a brief short in the wire.

has the pump been replaced recently?
 

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When someone says "tank unit" to me I think complete fuel tank and sending unit. If your baffles are indeed loose, That's exactly what you'll need to replace!
 

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Speaking English, I would have said replace the fuel tank. And technically, haven't a response that gets it right in my mind. Never heard of baffles in a fuel tank for a car. Makes sense like driving a tanker. Probably there on all cars all along, huh?
 

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Well, all fuel injected cars anyway. For instance, on GM G-bodies (1980s Cutlasses, Monte Carlos, Regals, etc.), the carbureted cars (which were 95% of them) had non-baffled fuel tanks. The fuel injected cars (turbo Buicks and FI 4.3L V-6 Monte Carlos) received baffled fuel tanks. A necessary swap, for someone who wants to put a TPI 305/350 into his car, is to get a gas tank from a turbo Buick or FI Monte Carlo so it has the proper pump unit mount and baffles in the tank to prevent sloshing. The sloshing isn't such a big deal with carbureted cars and mechanical fuel pumps, but with electronic in-tank pumps, I think they all have baffled tanks.
 

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kcnewell said:
When someone says "tank unit" to me I think complete fuel tank and sending unit. If your baffles are indeed loose, That's exactly what you'll need to replace!
The term "tank unit" refers to the ENTIRE sender/pump assembly. It has been coomonly refered to as a tank unit for a long time. Sorry, I assumed that it was obvious.
Anyway, the whole unit should be replaced on your car since the original design was defective and well known to cause the very symptoms you mentioned.

The baffled tanks did mainly appear with the EFI cars and the main reason for them as I recall was to help maintain a constant fuel supply to the engine via the in-tank pump. Also the baffle provides a well that stays full of fuel which keeps the pump cool.
 

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So now I've ordered a new tank. Having a hard time finding the part numbers for the sending unit and fuel pump. Parts sites show two different sending units and when I ordered the tank in town, they had two different pumps on hand, two cross reference numbers, but only one part number. Go figure. Is there a website that lists all the part numbers? My Cadillac repair manual doesn't list these particular numbers.
 

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I'm sorry, I did order the sending unit. But now just this morning with 15 gallons showing, she cut out on me. Starting to think it's just the fuel pump. Of course, buying the sending unit and fuel pump should get me covered. If it happens after that, tank or electrical. I had a Cadillac guy tell me today that he suspected the fuel pump. Huh!!!!!!!!!
 

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Hey guys!

Has there ever been any ride height issues associated with this fueling problem? Here's why I ask. Say you have 2 adults (300lbs) riding in the front of the car with no weight in the back, so that you initially change the ride height, and you're still having the cutting out problem. Then you head to the grocery store and add a 100lbs or so of them to the trunk. Our trip is 40 miles round trip. No cutting out whatsoever occurred on the trip home. Anyone checked this?
 

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I take it that the "Level Ride" is non op. because if it works that would have NO effect whatsoever.

Is that 300 pounds each or 300 pounds total? If it's the former...Them's a couple "O" big'uns. If it's the latter...Them's a couple "O" little'uns!:D
 

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that's 300lbs total. i'm going to pick up a sand bag and run awhile with that. am replacing the fuel pump, as everyone has suggested to me, and the fuel filter. the sending unit should be ok sense the guages (digital) works fine. i ran the a/c and the stereo on the trip into town and it starting surging and cutting out 10 miles down the road with 15 gal showing. we made it to town, bought groceries and headed back. the car ran like a champ however, we didn't run the a/c or stereo. the stereo has the power antenna.
 
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