Starting Problem

My 99 Taurus wont hold charge, i checked all fuses and relay and everything looks good, i also change the ALT and still nothing, the car only starts when i pump it, then shuts off when disconnected. please help.

Let me try to understand this:

Issue #1: The battery won't hold a charge. After the car sits for some time, the engine won't crank, or will crank slowly? The alternator was replaced in an attempt to remedy the battery capacity issue. Is this accurate? Was the battery load tested?

Issue #2: The car only starts when you pump it? Hmm, do you mean the engine will crank over fine, but won't start unless you hold the throttle open a bit? Pumping the throttle, with the car not running and the starter not turning the engine over should not have an effect on the car. The fuel injectors won't be letting fuel in to the engine if the engine is not cranking or running.

Issue #3: Only shuts off when disconnected. Are you saying the only way to shut off the running engine is to disconnect the battery? Turning the key to the "off" position has not effect, the engine continues to run? Do the accessories shut off when you turn the key off?

-Rod

Does your battery dash light glow when you turn the key to ON (before cranking)? Does the light extinguish when the engine starts?
Do you have 12 volts between the heavy alternator terminal and ground (heavy wire connected to battery) when the key is OFF?
How old is the battery? Are the terminals and connections clean?

My 99 Taurus wont hold charge, i checked all fuses and relay and everything looks good, i also change the ALT and still nothing, the car only starts when i pump it, then shuts off when disconnected. please help.

I had a similar problem, not a taurus, but was getting a drain, does your taurus happen to have a 175amp fuse? This fuse is usually near the relays. Hope this helps