Engine starts and immediately cuts off

[Cool81z28]

Here is a little background on my car. Last year I was having problems with my ignition switch not working. I did the resistor trick I learned on here and it corrected the problem.

While I was having the problem I wired in a toggle switch so I could start the car.

Yesterday I went to start the car and it would not crank so I used my backup toggle switch to start the car.

Now when the car starts it runs for a second or two then cuts off.

Could this be the ignition switch again? Any guidance on where to start diagnosing would be greatly appreciated. Thanks

1994 3.4 engine.

[Cool81z28]

Re: Engine starts and immediately cuts off

:banana:FIXED! Turns out it was the resistors I used to bypass the theft deterent system. When I made the bypass the first time the resistors came in packs of three so I made 2 extras sets just in case I would ever need them.

I removed the original I made and plugged in one of the extras and bingo everything works.

I guess over time the resistance must have changed enough in them to cause the problem.

Since this doesn't seem to be an uncommon problem in these cars I would recommend if you have to do it the first time make a couple extra and keep them in your glove box.

[joshk5145]

Re: Engine starts and immediately cuts off

Glad you got it fixed. Stuff like that can be such a pain in the A!! sometimes.

[nascar24jd]

Re: Engine starts and immediately cuts off

I had the same issue and finally did away with the entire system. I bought the $20 chip on ebay that eliminates the whole deal.

Haven't had a problem since.

[Cool81z28]

Re: Engine starts and immediately cuts off

I had the same issue and finally did away with the entire system. I bought the $20 chip on ebay that eliminates the whole deal.

Haven't had a problem since.

What kind of chip is it and where does it go? I'd like to look into it.

[nascar24jd]

Re: Engine starts and immediately cuts off

It is a tiny little chip that sends the pulse to the ECM to activate the fuel system.

It is a 2 step process. First you bypass the theft relay for the starter, then you install the chip. After that you are all done.

Here is the link:
http://shbox.com/1/pass_key.html

[Cool81z28]

Re: Engine starts and immediately cuts off

It is a tiny little chip that sends the pulse to the ECM to activate the fuel system.

It is a 2 step process. First you bypass the theft relay for the starter, then you install the chip. After that you are all done.

Here is the link:
http://shbox.com/1/pass_key.html

Thanks Nascar. I have the theft relay for the starter already bypassed but I have searched for a chip online and have not found one. Do you have a link for where I can get one?

[nascar24jd]

Re: Engine starts and immediately cuts off

Thanks Nascar. I have the theft relay for the starter already bypassed but I have searched for a chip online and have not found one. Do you have a link for where I can get one?

Here is the ebay link. This is a really great seller. He ships right away. This is the exact one that I bought.

http://cgi.ebay.com/ebaymotors/GM-VA...Q5fAccessories

[Cool81z28]

Re: Engine starts and immediately cuts off

Here is the ebay link. This is a really great seller. He ships right away. This is the exact one that I bought.

http://cgi.ebay.com/ebaymotors/GM-VA...Q5fAccessories

Thanks again Nascar. I just ordered it and I will hopefully have it by the weekend. It looked like a straight forward installation. Did you have any issues installing or any tips for me? Thanks again

[nascar24jd]

Re: Engine starts and immediately cuts off

Yes, you need to follow the instructions for 50hz.

Also, the VATS module is located behind the radio, up and to the right.

Remove the radio and you will see the wires off to the right side.

Other then that, easy install.

[Cool81z28]

Re: Engine starts and immediately cuts off

Yes, you need to follow the instructions for 50hz.

Also, the VATS module is located behind the radio, up and to the right.

Remove the radio and you will see the wires off to the right side.

Other then that, easy install.

Thanks for all of the info. I'm looking forward to eliminating this problem for good.

[nascar24jd]

Re: Engine starts and immediately cuts off

Thanks for all of the info. I'm looking forward to eliminating this problem for good.

That is exactly how I felt. Your problem will be gone forever.

[Cool81z28]

Re: Engine starts and immediately cuts off

Hey nascar24jd,

I received the chip I have a couple of more questions for you.

1. You said you hooked it up to the vats module behind the radio and up to the right. Mine has nothing there but I do have what looks like a control module behind the glove box all the way on the right side wall. Would that be it?

2. The instructions only talk about hooking it up at the ecm. Is doing it your way easier?

3. If I do hook it up at the ecm I am not sure which to hook it to. The only 3.4 the instructions list is a dohc engine. It says to hook it up to the dark blue wire but there are a couple of wires I would classify as dark blue.

4. Can you tell me which wire or what pin in which plug to hook it up to.

Here are the instructions.
http://www.xdponline.com/documentati...***_Module.pdf

Thanks in advance.

[nascar24jd]

Re: Engine starts and immediately cuts off

I connected it to the Vats module because you want to mount that chip in the car. You do not want it exposed to the elements. The Vats module already had power and ground so the hook up was really simple. There is a blue wire coming out of the Vats module that goes to the ECM, that is the wire that you have to connect to.

On my 1993 Firebird, the Vats module is behind the radio, and up very high. it is sort of between the radio and glove box, but it is so high up that you cannot see it. You can only see the wires going to it. The wiring harness runs along the plastic wall to the right of the radio. You might want to check again. It should be there.

I do not know the pin # in the wiring harness. I checked my service manual, but it does not give the pin #. What you can do is trace the Vats wires fron the bottom of the steering column to where they terminate. That will be the Vats control module. You can also trace the wires from the starter theft relay. That wire also terminates at the Vats module.

Good luck, and post your results. I will try to help out.

[nascar24jd]

Re: Engine starts and immediately cuts off

Oh, one more thing. In the LT1 tech website that I sent you it does mention the Module located to the right side of the glove box. Maybe the 1994 has it there as opposed to my 1993.

Trace the wires back like I explained and you will find it.

Then look for the blue wire.