Schleusner

PleAse help!! I want to disable the antitheft system on my 89 iroc. It will sometimes flash security and crank but no spark. But other times the security light wont come on and it wont crank. It has vats and its seriously is frustrating. Anyway to bypass the anti-theft so i dont need to replace the ignition switch???

Injuneer

Shoebox has the procedure for a 4th Gen (93-02). I suspect the 3rd Gen is very similar. See if this helps:

4th Gen LT1 F-Body Tech-PassKey/VATS

4th Gen LT1 F-body Tech Articles

4th Gen LT1 F-body Tech Articles

In the 4th Gens, the PASS-Key system does not involve the ignition switch itself. The only thing used is the key cylinder, which has the two contacts that read the resistor in the key. First step is to clean the contacts on the key, and try and clean the contacts in the key cylinder.

Could also be loose wires on the contacts in the cylinder. The "flashing" indicates an incomplete circuit, not an incorrect resistance value.

Again, all this is based on my (and Shoebox's) knowledge of the 4th Gen. Hopefully, the 3rd Gen will be similar.

Schleusner

Looks like i will need a 400 ohm resister. Hopes that works to just by-pass the vats. The ohms i was getting was all jacked up and would change when i bumped the key. I would hate to replace the whole cylinder.

Schleusner

put the resister in and the security light does as it should and the car cranks but still no spark. I had the ignition moduel checked i put a new coil and an getting voltage to the coil. What the heck!!!?? What else should i check?? I didnt see any bad fuses or anything. Snow is going to fly soon.

TGGodfrey

you have two different issues. VATS you have figured out.

Lack of spark:
Did you test for ground to the HEI?

You tested the Module.....I expect it tested good?

Test the coil primary and secondary winding next.

Test the pickup in the distributor. This is a two wire inductive pickup. Put an ohm meter on the two wires and make sure there is a resistance reading. This tells you the circuit isnt burnt open. now leave one lead on the pickup and place the other test lead on the housing of the distributor. This should be no reading indicating an open circuit. This tells you the pickup isnt shorted to ground. Now with both test leads on the pickup leads, sping the distributor. the Ohm reading on your tested should fluctate. This indicates a good pickup.

Schleusner

Yes VATS is good. soldered in a resister and the light does everything it should. Will take distributor cap off on my lunch break and check what you told me to. Yes, the ignition module checked good. Thank you so much for the reply. My camaro book I have seems to really focus on the carb stuff.

Schleusner

ok here is what I got. 300-600k ohms wire to wire on the pickup coil. Fluctuated the whole time. From one pin to the distributor housing was open and the other has a 30m ohm resistance the green wire. Does that mean its bad?

Schleusner

ok, replaced the pickup coil and she purs like a kitten Again. Thanks all!!