you drop the fuel tank and replace the sending unit
A 1999 Isuzu Rodeo that starts and then dies is not getting enough fuel, or the fuel mixture is off. It could be a clogged fuel line, dirty fuel filter or the fuel pump. It will need to be serviced.
Where is my filter for my 97 ISUZU RODEO
More than likely the fuel gauge sending unit located in the fuel tank is faulty.
Some causes for a 1999 Isuzu Rodeo to stop running include a lack of fuel, a bad battery, or defective spark plugs. There can also be a combination of issues which would need to be diagnosed by a mechanic.
at answers.com
On the left
A 2000 Isuzu Rodeo has a 21.1 gallon fuel tank. The estimated fuel economy is 8 mpg city, and 21 mpg highway.
The fuel sending unit is part of the fuel pump in the gas tank and both must be replaced to fix the problem. The fuel pump is part of the 100,000 mile warranty.
top of gas tank
after u drop the tank and replace the fuel sending unit your gas gauge should start working correctly. try jcwhitney.com they seem to have the cheapest price on the unit and pump combo.
need a 1999 izusu rodeo fuel lines diagram
under the driver's door to your right.