I own a 1986 C-4 and I have problems sometimes starting the car. Most of the time, it starts right up, on occassion, I'll turn the key and nothing happens, then I have to turn the key 4 or 5 times and then the starter will turn and engine will kicks over. I'm not sure if it is a VATS or a key problem. I only have one ignition key so I can't try the spare. I have cleaned the pellet figuring maybe that is it. If it is an ignition switch, are they easy to replace?

 

When you insert the key, turn the ignition to run.
The Security light should light for a second then go out if the key
pellet was read properly.

If the light stays on it could be any of the following. The pellet is dirty or worn out. Solution is to replace the key.

The ignition key cylinder is worn out. Solution replace the key cylinder.

If the Security light stays on, the Pass Key Module will not energize the starter relay for about 5 minutes. You must wait for the time out to complete. If you try to start the vehicle during the time out period the timer is reset.

If the Security Light does go out, you have some other problem and need to trouble shoot the starter circuit.

 

Usually if it the VATS 'security' will blink or be on (cant remember which one), also look at starter as well as the ignition switch.

 

I could understand it if I had to wait 5 minutes but by turning the key a few times it will start. I had a simular problem a year ago but the only way the car would start was to disconnect the neg. ground cable from the battery. That turned out to be bad cables, I replaced them and everything has been fine for about a year.

 

Does the starter solenoid click each time you turn the key to , "crank", position?

 

No clicking at all, its like there wasnt a battery there, then I will turn it again or again and it starts like it was new.
( I just love this forum! )

 

Most likely it is VATS. Wait 6 minutes when it won't crank and try your spare ign key as its pellet contacts aren't worn like your everyday key. The ECM won't allow a crank for 6 minutes if it doesn't see the correct pellet resistance. Next, unplug the clutch safety switch (gear selector sw at base of gearshift if automatic) and jump the socket. Measure the voltage on the jumper when you hit crank position. If you have 12v and no cranking, then you have battery connection problems (clean your battery connections) or a starter problem. You can jump 12v to the safety sw jumper and your starter should crank proving the starter is good. If no 12v, then pull the kick panel above the drivers feet and find the 2 wires from above the steering column that go to a 2 pin connector and unplug. Insert your key and measure the resistance across the wires from the steering column. It should measure the same as your pellet. If not and/or over 13k ohms, you need a new ign lock which will have new contacts that make connection to the pellet. You can temporarily bypass VATS by connecting a resistor the same value as your pellet across the 2 pin socket (goes to VATS module) until you can schedule a lock replacement. The resistor must be within about 4% of the assigned value of your pellet. You can use a 1/4 watt 5% resistor from Radio Shack. Don't permanently bypass VATS because 99% of thefts are done by bashing the column and jumping the ignition.

 

[QUOTE=jfb;1560758459] you need a new ign lock which will have new contacts that make connection to the pellet... QUOTE]

Does anyone know what the installed cost of a new ignition lock & new keys might be?

 

If you check for codes, do you get a code 46 ?
http://members.shaw.ca/corvette86/Code%2046.pdf
http://members.shaw.ca/dankai/Vats%20Electrical.pdf

 

I haven't a scanner and so far, it hasn't left me stranded, just turn the key a few more times and it starts, no waiting, that is why I figured maybe worn contacts in the switch. I'll do some of the checks mentioned here. If it is the key switch, is it hard to replace?

 

A little confused, are you saying that if you keep turning the switch it will start? A bad VATS will lock you out for 6min (no 6mn wait, no VATS problem. Security light off, no Vats problem (in (99.99% of the time). My guess in order of probability, starter solinoid, neutral safety switch/clutch switch, ignition switch (Ignition switch and key tumbler are different in a C4. its down about 18in on the column) If it is a bad key tumbler asm, they're about $40 at GM, and you need to get another key made with your VATS code on it.

 

Yes, I do not need to wait, just turn the key again, or again, usually by the third time, the car will start. It doesn't do it all the time. I checked wiring on solenoid and all is tight there.

 

Then you don't have a VATS problem. Loose conections aren't usually the problem. What is the problem is electro/mechanical devices that have contacts. These contacts wear, get dirty, arc etc. Not saying this is your problem, but this is the way starter/solinoid problems act.

 

zr1Fred, I think you may be right, I was outside trying it and after a while I got it to NOT turn over and there was an audible click. Guess I'll check out the solenoid. Thanks

 

If you hear the solenoid clicking but no cranking, you may have burned contacts in the starter motor that can be replaced. At the end of the solenoid stroke the solenoid forces two large copper contacts together to switch current to the starter motor. These contacts get burned and pitted and become unreliable.

 

jfb, Thanks, I'll check that next. Nice to have all these people helping one another.