1993 4.9 DeVille fuel puzzle
 

This car has 122k on it. I am puzzled with the following symptoms. The car runs good when the fuel tank is full. when it gets below 6 gallons it runs progressively worse (no stalling but missing, jerking, like its a fuel issue) till I fill it up. when its hot but freshlly full of gas it runs only slightly better, but it runs good agian the next day after its cold. I could add that the car has thrown a transmission code relating to the torque converter so the transmiision shop says it's that. I could add that the car has all ways (since we bought it with 40k) from time to time had the check engine soon light come on and the dealer told us it was a phantom, we've ignored it with no consiquence.


I am thinking its just a fuel pump but I am usually wrong with my guesses.

any input would be appreciated.

RE: 1993 4.9 DeVille fuel puzzle
 

Hey there Bat: Sounds to me that you may have water in you tank. If you think this might be possible, try dumping some Methal Hydrate in the tank. It will mix with the water and then make it possible for the engine to burn it. Hope this helps. Chow.

RE: 1993 4.9 DeVille fuel puzzle
 

run the codes my 92 deville did the same thing it turned out i needed a new camshaft position sensor