Why wont my mitstubishi 1999 Eclipse GT start after putting in a new stearing column

Put the switch from the original column into the replacement column. Problem solved. The original key is programmed to the receiver in the dash that's hooked to the computer.

the immobilizer receiver is in he steering column
removing the steering column is the problem

The key problem is most likely your ignition switch.

ignition key on engine not running unplug ignition module connector there is a purple/white wire with a test light to batt + touch and release many time you will hear a clicking sound and a spark tester at one spark plug wire if yes look for defect crank sensor or ignition module
hope it helps

find out where its leaking from first or just put on a new power steering pump

You'll have to get the ignition key and lockset from the old column and put it in the new. Theres a chip on top of the lockset that is encoded with the security system. You can do a key relearn, but you have to have the original chip.

Here's a company that has pages and descriptions of how toreplace the ignition switch on GM vehicles. They are broken down into step by step detailed instructions. Here is alink to that page. They covers many ofthe in-dash ignition switches from 1997 to 2006 too. http://www.steeringcolumnservices.com/steering-column-repair-how-to-instructions/gm-buick-cadillac-chevrolet-oldsmobile-pontiac.php Lastly, I would have a new switch in hand before you begin, tosee what you are working on (hidden in the column) and accomplish finishingthis job quickly. Good luck

get a doner stearing column from nearest salvage,(thats what i would try). youll prolly have to buy a new key tumbler assembly and program the key to the computer anti theft sytem.
to program the new key, assuming all goes well with the new column and the new key tumbler,put the new key in ignition, turn key on for 15min, time it with a watch. after 15 min turn key off.
wait 15 more minutes. time that,
now after the 15 minutes u should b able to turn key on and start the vehicle.
the key tumbler/key switch kit should come with those instructions.
also if u buy a doner stearing shaft, i like when they let me pull it, lock the stearing wheel w/key so it doesnt turn.
there is a sensor called the "CLOCK SPRING," if u turn the wheel to far around while disconecting the stearing shaft at the bottom of column, u ruin this sensor and end up with a airbag lite on.
so b careful not to rotate the wheel more than two times in one direction the sensor is about 119 bucks u dont have to remove the stearing wheel to swap the column assemblys

If your signal light stays solid when you go to use your signal, then one of your bulbs has burned out.

Depending on the bulb that burns, it'll either flash rapidly, or just stay solid

It could be the temp sensor. Have you had a diagnostic OBDII computer put on it? You should have your codes checked for easiest troubleshooting and diagnostics. Mabey you have a short in the wiring. Have you checked new maf with digital ohmeter to check wiring for resistance?