express van will turn over fire and stall

i have a chevy express van 2000 with 7.4 vortec when i turn the key the engine turns over & fires immediatly and stalls i have tried many times and its allways the same when it stops the security light flashes a few times and then goes out if anybody has any sugestions as to the cause of this problem i could use the help thank you new member

i have a chevy express van 2000 with 7.4 vortec when i turn the key the engine turns over & fires immediatly and stalls i have tried many times and its allways the same when it stops the security light flashes a few times and then goes out if anybody has any sugestions as to the cause of this problem i could use the help thank you new member

Welcome to AF on your first post.

Security light staying on or flashing is not good.
It points to anti theft being tripped or on.

Is it the oem anti theft system or any add on remote start or anti theft stuff?

Has any recent work or repair or parts replacement?

You might try the old key on 10 minutes until security light goes out for 3 times and the key off and then see if it will start.

If that does not do it you may need to get it on a anti theft capable scanner and read out data and get codes.

If you get any anti theft codes post back code.

Let us know how it goes.

mine is doing the same but no security light.
Anyone have a schematic showing the modules the pass code reads from. anyway to by pass the BS?

mine is doing the same but no security light.
Anyone have a schematic showing the modules the pass code reads from. anyway to by pass the BS?

First thing make sure it is a anti theft problem.

Fuel pressure and other things act like that to.

Run a full fuel pressure check on it and post back fuel pressures.
They have to have full fuel pressure to squirt injectors on a cold start.

Does security light come on for a bulb check key on and then go out or stay on after trying to start?

A engine body capable scanner check out is the first step on checking anti theft problems.

There is some bypasses but I always like to find and fix the problem rater than try a bypass that can lead to more problem.

For wiring schematic and trouble shooting/repairing the system a factory repair manual or a All Line All-Data DIY info subscription is your best deal.

First thing make sure it is a anti theft problem.

Fuel pressure and other things act like that to.

Run a full fuel pressure check on it and post back fuel pressures.
They have to have full fuel pressure to squirt injectors on a cold start.

Does security light come on for a bulb check key on and then go out or stay on after trying to start?

A engine body capable scanner check out is the first step on checking anti theft problems.

There is some bypasses but I always like to find and fix the problem rater than try a bypass that can lead to more problem.

For wiring schematic and trouble shooting/repairing the system a factory repair manual or a All Line All-Data DIY info subscription is your best deal.
Its not the fuel system. Its the pass code system that is screwey. It kills power to the injectors after the intial crank up.
I just need some one that has the the diagrams of GMs Pass code BMIs to help me.

Its not the fuel system. Its the pass code system that is screwey. It kills power to the injectors after the intial crank up.
I just need some one that has the the diagrams of GMs Pass code BMIs to help me.
What code are you getting?
How are determining that it is the Anti theft?
The diagrams will not help with out checking the system out and finding the problem.
All Data On-line DIY repair info subscription info has all diagrams and also the repair info to go with them.
Good Luck