95 Buick LeSabre Starts then instantly dies

buick
lesabre

#1

My 95 Buick LeSabre will start just fine then it will immediately die. Could this be the VATS, PassKey or PassLock causing this problem?


#2

What happens if you start it and give it just a little bit of throttle. Will it keep running?

I am not familiar with the details of the VATS, PassKey etc. - but presumably those are the electronic security-related things? If so then it shouldn’t start at all - as in no ignition activity.


#3

sounds like security. Thats the way it works on these cars. Do you have a pellet in the key? The most common problem is the wire breaks in the column thats attached to lock cylinder. Post back on here if you have a pellet or not. It will help us help you.


#4

It also sounds like a security system problem to me. They can be a real pain to correct.


#5

i do not think VATS is used on this vehicle. are there any codes in the system? could be many things, TPS, cam position sensor, ecm problem. if the wire were broken in the lock and key assembly it will not start at all


#6

Yes, It does have a pellet key, and the security light flashes for a second as well. I have heard that the wire breaking is common, but since it turns over and starts for a second kinda made me think that wire might still intact? But I have no clue, and it looks like it will be very difficult to get to that wire. I have been contemplating getting a VATS bypass module and installing it. Has anybody heard of those?


#7

The problem might be with a faulty ignition module.

Ignition modules function in two modes. These are the start and run modes. When starting the engine the ignition module goes into the start mode which allows full battery voltage to the secondary ignition system. This ensures there’s enough spark to the cylinders to ignite the rich fuel mixture when the engine is cold. Once the engine starts, and the ignition switch moves to the run position, the ignition module switches to the run mode. The module then reduces the voltage to the secondary ignition system. Doing this prevents damage to secondary ignition components such as the coil packs.

So the ignition module may be working during the start mode, but failing in the run mode. So the engine starts, but shuts down as soon as the ignition switch moves to the run position.

Tester


#8

thats the way the security system works on this car. one thing you can do if you’re electrically inclined is to use a digital volt/ohm meter. read the resistance on the pellet in the key. you can then go to radio shack, get a resistor with the same value. Under the dash coming out of the steering column you will see an orange wire. trace it down to where it connects and you will see two white wires come out of that orange one. cut the white wires leaving enough room to solder the resistor to those wires. This will bypass the security system, but if that indeed is your problem the car will now stay running. Have fixed a lot of them this way with customers who did’nt want to spend 120.00 on a new lock cylinder. Good luck


#9

Thanks for the great advice. While I wasn’t confident enough to do any soldering, I was able to detect the resistor value of they key using a volt/ohm meter like you suggested. I then bought a part called a “VATS bypass module”. After taking as much of my dash apart as I could, I realized there was no way I could access the plug, but I was able to locate the wire and splice the module into place. I then put the key in and gave her a crank, and she purred like a kitten. Thanks so much for you help…

Charles