No Start Problem; VATS???

[Lyle Haws]

'86 Coupe with 117,000 miles..ignition lock "froze up"...would not turn with key...I measured resistance of Key Pellet...4600 on my Multimeter...bought a stock resistor (4750) from radio shack and wired it into the VATS unit under dash. Then changed out the ignition switch (oh, what fun!).

New switch works fine, but NO start...and when ignition is turned to engage starter, I hear a "sizzle" sound for about 10-15 secs. Then nothing...starter does not try to engage.

Does this sound like a VATS prob??? Wrong resistor??? Is there a way to show "Codes" that would indicate the problem??? Car is partially torn down for restoration so I don't want to have it hauled to a repair shop if at all possible! Thanks in advance!
:confused

 

[69MyWay]

I just went through this on a trans am.

It is no big deal.

First, throw away that resistor.

Go to your local auto parts store and buy a new ignition lock cylinder (I assume yours broke). They come with the wire harness for the VATS.

Then, take your registration and I.D. to the local GM dealer and have them match a key to the new lock cylinder with a VATS chip in it (about $30).

Now, open the column, install the new lock cylinder, feed the VATS wire harness down and plug it in.

Hopefully that will do the trick.

 

[KOPBET]

I'm curious why you chose to try and bypass VATS when you replaced the switch. If all is well, then no bypass should be necessary, I would think??

4750 ohms is correct if the resistor truly has that value. Range is fairly wide and 4750 ohms is the center of that range.

I am assuming (dangerous I know) that you put the resistor on the upstream side of the connector, the side with the colored wires and not the side with the white wires.

 

[Lyle Haws]

The VATS system was giving problems (intermittent No Starts)before the ignition lock went out, and the expedient solution seemed to be to bypass that issue and use an ignition lock w/o the key pellet...plus the non VATS ignition lock was $12 bucks at AutoCrap store, vs. $45 for the VATS lock.

However...what's that line about "The best laid plans....."????

Yes, I did install the resistor in the harness w/ the two colored wires going to the VATS module...am going to try a new resistor and put it in with the ingnition in the "run" position and see if the VATS module will "click" to indicate funtioning...

Any other ideas will be welcomed! Thanks folks!! :confused

 

[69MyWay]

Hey Lyle,

Is it possible your ignition switch (not the lock cylinder) is bad, or out of adjustment? In other words, your twist the key, but the rod does not push the switch all the way forward to start...however, it does cycle the fuel pump and IAC..etc, so you get the sizzle noise under the hood??????

If so, you have a $12 problem on the column.

How can you find out?

Simply twist the key forward, with your resistor in place, get under the column, grab the starter feed wires, pull it from the switch and jumper to power. If she starts....(or at least spins over), chances are you whole problem was a faulty ignition switch, not VATS.

Secondly....I do suggest you follow the full replacement procedure so that the key is normal again. Why? Well, if you go to sell the car, it will raise questions to a savy buyer as to why the ignition has been monkeyed with. Second, if the 86 module is like the newer ones, it can't tollerate being hit with multiple different resitor values. It can only relearn one time. If you you take it through a relearn procedure inadvertantley with a resistor that is off, it will render the unit useless (if you don't get it going with the odd ball one), for going back stock, and you will have to replace the module. (at least that is how they work as late as 95--I don't have a 86 book to referrence.)

 

[Lyle Haws]

And the bottom line is...try and save a few bucks and probably cost myself more in the long run!

Your point is well made, and now that I have had everything "undone" once, it won't be very difficult to install a proper ($45.00) new VATS ignition lock with the correct value resistor key.

Luckily, I have not tried a variety of resistors...I measured the resistance pellet in the original key, which did work originally, so it has to be the correct resistance for my VATS module. Also, luckily, this is a hobby car and not my "Daily Driver", so I can take my time and learn as I go here!

My guess is that you may have hit the mark when you suggested the new (cheap) ignition switch is not depressing the starter engagement link. Now I just have to test it.

As far as resale of the car someday...she has 117,000 miles now and will have a few grand more by the time I am ready to part with her, so the next buyer probably won't be too concerned about the state of the ignition system, if it runs at all by that time! I'm thinking "Scrap Yard" !!! Thanks again for the suggestions!!!

 

[Lyle Haws]

Well, the Problem is solved!!! Turns out, as another individual advised, my analog Multimeter was giving me a bad readout for the resistor (4750K). I broke down and bought a new Digital MM at Radio Shack for $30.00 (ouch...yes, I'm "thrifty"!). Checked my old key resistor right there in the store (I could have used theirs, but that would have been REALLY cheap!!!) and got a reading of 3010K. Bought 5 of those resistors for $.99, and headed for the garage. Popped one of the 3010K's in the VATS harness, stuck the new key in the new (and cheap) ignition switch, and VAROOOOOM!!! The old girl sounds better than ever! And if I want to disable the car for theft protection, I can reach under the dash and pop the resistor out and it won't go anywhere under it's own power!
Anyway, thanks to everyone for their advice...maybe it will help someone else down the road!

 

[69MyWay]

Great news!!!!!!!!!!!!

 

[KOPBET]

Good job Lyle!