hi,

sometimes ago this happent to me, under several occasions: my '88 vette did not start. everything was lighting up in the dash, but when turning the key further, the starter did not move. i read in the manual that somethimes the restistor in the ignition key might not close the circuit and the security feature was not being deactivated.

but after 5mins usually the car would start if attempted again.

now it did not start. not after 5 mins, 10 or 15. not even the next day.

dash lights up and when i turn the key further the stereo goes off, meaning the car is aware i am trying to start the engine. but the starter does not spin at all.

one thing is different: 1 days ago i washed the engine of the car. not very thorughfully, but there was some water all over the place. but the car started after the wash and i drove ot for a while before i parked.

1 how can i check to see what is the cause for this problem?
2 how can I disable permanently the key resistor security feature?
3 i'm thinking of trying to trick it this way: turn the ignition on, then go under the car and apply 12V to the starter motor directly. what do you think of this?

thanks,
radu

 

You can build or buy a vats bypass. Direct wiring to starter, not a good idea. Do a search on "vats bypass".

 

When you insert the ignition key and turn the key to On. The Security light in the Driver Information Center should go on for the bulb test and then go out.

If the Security light stays on, the key pellet resistance didn't match the value the Pass Key Decoder Module was programmed for.

A random length timeout period will take place where the starter will be disabled.

Could be a dirty key pellet, bad key cylinder contacts, broken wires at the key cylinder (replace key cylinder) or very rarely bad Pass Key Decoder Module.

To help trouble shoot where the problem is, for test purposes you can disconnect the small two pin connector at the base of the steering column and place a resistor with the value of the key pellet resistance across the connector going to the Pass Key Decoder Module.

If the Security light does go out, could be a bad starter enable relay, neutral safety switch, starter or starter wiring.

 

That to me indicates the the starter is drawing power but not turning.I would be checking the starter / battery first.
What are your indicated batt volts?
Can check starter operation by running wire from solenoid terminal on starter and touching on batt + with ign off.
Out of gear if manual

 

If all the dash lights go out when you attempt a crank, you may have a poor battery cable connection or a bad battery or discharged battery.
Measure the battery voltage when you hit crank position, the voltage at the battery terminals should not fall below 9.0 volts or you have poor cable connections (remove cables, clean cable lugs, bolts, battery terminals and replace), a discharged battery (no load battery voltage is 12.0 volts discharged and 12.9 volts fully charged and linear in-between), or a defective battery. Charge the battery if it is discharged.
Do you hear the starter solenoid click when you hit crank position? If not and the battery voltage is ok, then you may have a defective clutch safety switch (gear selector switch if automatic) and you can jump the switch and try a crank. You should measure 12v on the clutch switch jumper when you hit crank and the starter should crank. If no 12v, then you may have bad contacts in the ignition lock which makes connection to the pellet in your key. Pull the hush panel above the drivers feet and find the two wires from above the steering column that goes to a 2 pin connector. Unplug, insert ign key and measure the resistance across the 2 wires from above the steering column. It should measure the same resistance as the pellet. If more than 4% different, you need a new ign lock which has new contacts. Until it gets replaced, you can bypass VATS by connecting a fixed resistor the same value as your pellet (must be within 4%) across the 2 pin socket in the wiring harness. Don't permanently bypass VATS because 99% of car thefts are done by bashing the steering column and jumping the ignition.
If you hear the starter solenoid clicking when you hit crank, keep hitting crank over and over and if the starter eventually cranks the engine, you have worn contacts inside the starter which can be replaced, or you can install a new starter or have yours rebuilt.

 

I had a similar problem with my 88. Make sure your battery is good. If it is and you continue to have this type problem you can go thru the vats key bypass and all the agony I went thru trying to fix this problem. I finally got a vats bypass chip and installed it in my ECM (PCMforless.com) and have not had that problem again. MY 2 cents

 

guys, i think you misunderstood me. when i say "the lights go off when i try to start the engine" i meant that some of the warning lights in the information panel, together with the radion, go off, and two others light up, while the dash gauges stay on. to me, this was only an indication that the key cylinder actually senses the fact that the key is being pushed to start.

a regular cylinder should have 4 wires: +12V, accesories, ingition on and start. which all seem to work.

corvette probably has two more, the ones that measure the key impedance / resistivity. here i think it is the problem. i will try more debugging tomorrow.

---

so you say one thing is sure: the current that goes thru the key is DC (so only resistivity matters, not impedance) right?

thanks,
radu

 

The fact that the battery is drawing down in the start position shows that it is not a VATS problem.

VATS problem = zilch; nothing happens because the starter enable relay is not operated.

 

i was planning to do this only to check if it's not the starter motor problem. not for regular use, of course.

 

and if it is the VATS module then the kit won't work (from what i read on other website)... i guess that can not be also bypassed. so - where is this vats module located? i want to inspect it, see if looks burnt or something is wrong with it.

thanks

 

The VATS module uses D.C. to measure the pellet resistance. It is rare for the VATS module to fail. On my 87, the VATS module is behind the instrument panel behind the fuse block. I own an 87 and drive it everyday with 229k on the odometer. I'm on my third ignition lock. I will continue to repair my VATS and keep it working. Why anyone thinks VATS is,"agonizing", is beyond me. Checking it is simple, and bypassing it is simple, so is repairing it. Most crooks are looking for an easy steal and VATS prevents it.
I bought my 87 from someone taking delivery of a 90 vette. One day they came out of work to find the driver window busted and the steering column also busted apart, but the 90 hadn't budged an inch. Keep your car in good repair!

 

i guess it's simple only as long as you have the key

 

here's a more acurate description of what's going on:

open door: "security" blinks for a while

ignition on: various lights in instrument panel go on and then off, but security stays off. the only lights that stay on are "service engine soon" and "battery". dash battery = 11.7V

start engine: "brake" and "anti lock" come ON, "battery" and "service" remain on while the stereo goes OFF. dash voltage = 11.7

i think this takes out of the question the battery. possible problems: starter, starte relay, cylinder lock, VATS module. i will hotwire the starter motor to check if it is good, as this is a common failure. if that one is ok then i will try to trick the VATS with using a resistor with the same resistance as the key.

if this will not give me the answer, then it's either the VATS module or the starter relay and i will ask for more help.

i will keep you posted either way. thanks!

 

Don't forget also the inhibitor switch in shifter (auto ) or clutch switch (man)
These are part of the starter circuit .

 

MY 88 DOES THAT ! MY STARTER TURNS ( YES MINE ONLY LOCKS OUT THE INJECTORS) BUT IT WONT START !
I HAD A HOME MADE BYPASS I MADE ! IN THE CAR HIDDEN ,PLUGGED IT IN AND AWAY I WENT! THESE OLD ELECTRICAL CIRCUITS DONT ALWAYS FOLLOW THE RULES , I HAVE FOUND THAT THE DODGY REPLACMENT VATS KEYS R THE MAIN CAUSE, HOPE YOUR PROB IS AS SIMPLE AS MINE

 

when i press the button on the shifter i can hear a small "click" in the dash, so i think it works...

 

Dash voltmeter reads low when the engine isn't running. If you read 11.7 volts engine running, then you should also see the red battery symbol light on which tells you that the alternator is not charging the battery and also, car batteries are considered discharged at 12.0 volts and below. Discharged batteries don't supply enough current to starter motors to allow them to crank! Charge your battery up with a battery charger! and fix or replace your alternator.

 

Tried smacking the starter yet? I've put in 3 warranty NAPA premium starters in my 88 and the 3rd is on the way out again, I carry a 2 foot long 1/2 inch pipe just for these special occasions....

 

is the pipe for hitting the starter?

i did not get the chance to work. car got stucked away from my home and i will have time to deal with that in the weekend only.

 

If the VATS security light goes out after the ignition key has been turned to the run position for a second or two, then the decoder box has recognized the correct resistance from the pellet in the key. Then only thing it can be causing to not start is the starter enable relay or the nuetral start switch & of course a bad starter.

The decoder box (vats module as you refer to it) is pretty pricey I believe its about 300 bucks if vats were the problem the vats security light would remain on after the ignition has been in the run position for more then 4 seconds. The security light on the instrument cluster has nothing to do with vats. the security light for vats is in the information center.