Car want start until serveral attempts - 2000 Chevrolet Tahoe

run the fault codes to find the faulty sensor/s

don't know anything about this but, could your ignition key be coded to your old LCM?

You will need to contact the dealer for this information, it is stored on the factory server data base for the car.

You have to do a relearn procedure on the anti-theft system:

Attempt to start the vehicle. Leave the ignition on until the THEFT SYSTEM indicator turns off (about 10 minutes). Turn the ignition switch off. Leave the ignition switch off with key in for about 10 minutes. Attempt to start vehicle.

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1. The engine does not have any fuel system screw bleeder!
2. The only one way for start the engine is to fill up the tank, then turn the ignition key in "ON" position for 4 - 5 times, wait for 10 seconds between two attempts, without cranking engine.
3. After that push the clutch pedal, (if exists), to the floor, and the accelerator pedal to the floor too. Now turn the ignition key in "ON" position, wait for 5 seconds, and crank the engine for maximum 40 ... 50 seconds. Wait for 60 seconds between two starting attempts, in order to save the battery & starter motor.
4. Repeat the step no.#3 until start the engine.

IMPORTANT NOTE: DO NOT TOW THE CAR IN ORDER TO ATTEMPT TO START THE ENGINE!!!

Guys hope yourl keeping well

Ive got a 1998 A6 2.8 Quattro
Ive changed the gearbox and the vehicle dont start now.
the engine swings from the starter but when using the key it turns once and nothing happens thereafter the key is locked in on position where im getting ignition lights

Can anyone help???

Bad connection at battery

Try shifting the shifter when this happens to see if it is related to the PRNDL in the transmission; you of course will have to have the key in on possition to attempt this. If this doesn't work, you will need to take it to a quaified mechanic since there are serveral test that will be needed to be find this issue, but let me assure you that the security light comes on and blinks often when starting the vehicle.

try the 10 minute re-learn:
put key in ignition and attempt to start, let off the key and leave in the run position for about 10 minutes or untill the security light goes out, shut key off and wait 5 seconds, attempt to start vehicle normally, it should start.