I HAVE A 99 CHEVY EXPRESS I THINK ITS THE IMOBILIZER IT START BT RT AFTER IT TURNS OF RT AWAY

hi george.
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Test for spark at plugs (use a timing light if available). If no spark, have ignition module tested (most parts stores do this free) and test coil(s) with ohmmeter. Nothing? Next test crank/cam sensors.

is the battery charged try getting a jump start from someone if it still wont turn over its the starter possibly could be the imobilizer but on my merc it turns over fine but will not start when the imobilizer is on

Chances are your Imobilizer is keeping your car from starting, try using a different key. Is the car cranking and then shutting off a second later? Any lights flashing on the dash? Highly unlikely that a brake fluid leak would prevent your car from starting. The only way thAt would be possible is if the fluid leaked onto a module and ate away at your board.

the high humidity (water) is attacking your electrical starting system, whens the last time you changed your spark plug wires , distributor cap & rotor ? how about your fuel & air filters ? cleaned your battery terminals ? try it , it will help !!!!!!!!!

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Car not starting or turning over indicates towards multiple possibilities. It can be issue with battery or weak battery. But if battery checks out ok, then it can be starter issue or faulty alternator or problem with low fuel pressure or no spark at spark plugs due to dirty spark plugs or faulty ignition coil or injectors getting cracked or dirty and needs to be cleaned.

To confirm the problem, the basic troubleshooting is required.

Click this link below and follow the troubleshooting:------

http://technoanswers.blogspot.in/2012/02/car-starting-issues.html

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This will help.

Thanks.

Will it run for a short time if you squirt some fuel into the throttle body? If so, then concentrate on the fuel delivery system. Fuel pressure at the test port on the fuel rail should be at least 40 PSI. If not, look at the fuel pump, the pressure regulator, and the fuel filter.

get a auto electrition to bypass the imobilizer.

THE CRANK SENSOR IS LOCATED RT UNDER THE CRANK PULLEY. IT IS USUALLYEASIEST WITH AN EMPTY TANK TO REPLACE IT.