VATS Question - 1987 Vette
Thread Starter
Heel & Toe
Joined: Apr 2017
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VATS Question - 1987 Vette
1987 Corvette, manual.
I have the random, no start, no crank issue.
After I leave it alone for 15 minutes, it starts up
The key resistor issue has been bypassed.
Still had the random, no start, no crank issue.
Just changed the Starter Relay behind the radio panel. Started right after install, but next day got in and still have random, no start, no crank issue.
I believe there is only one other VATS issue it could be ?
The Cranking Fuel Enable signal. ?????
Would this cause the same no start, no crank issue. ???
If so, could someone describe the fix to me, or point me in the right direction ?
Bob
I have the random, no start, no crank issue.
After I leave it alone for 15 minutes, it starts up
The key resistor issue has been bypassed.
Still had the random, no start, no crank issue.
Just changed the Starter Relay behind the radio panel. Started right after install, but next day got in and still have random, no start, no crank issue.
I believe there is only one other VATS issue it could be ?
The Cranking Fuel Enable signal. ?????
Would this cause the same no start, no crank issue. ???
If so, could someone describe the fix to me, or point me in the right direction ?
Bob
Team Owner
Joined: Sep 2003
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You haven't mentioned the clutch safety switch. If you're confident that the resistance bypass is done effectively I'd be inclined to start there if the starter enable relay is good. If you've the FSM there's certainly procedures outlined for diagnostics.
If you don't have the FSM (Factory Service Manual) I'd suggest you buy one.
The resistance bypass was done why?
There's a difference in NO START and NO CRANK, you have intermittent NO CRANK or you have intermittent CRANK NO START?
If you don't have the FSM (Factory Service Manual) I'd suggest you buy one.
The resistance bypass was done why?
There's a difference in NO START and NO CRANK, you have intermittent NO CRANK or you have intermittent CRANK NO START?
Last edited by WVZR-1; Oct 9, 2017 at 08:13 AM.
Thread Starter
Heel & Toe
Joined: Apr 2017
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I have a key with no resistor on it and it works fine. A mechanic did it years ago, cant remember why. Think I might had had the Key Resistor issue.
Never checked the clutch safety switch, didn't realize that it could be the source.
To clarify, Intermittently, I put the key in the ignition, everything lights up as usual, but when I turn to start, nothing happens. No clicking, no dimming of the lights, nothing.
Never checked the clutch safety switch, didn't realize that it could be the source.
To clarify, Intermittently, I put the key in the ignition, everything lights up as usual, but when I turn to start, nothing happens. No clicking, no dimming of the lights, nothing.
Team Owner
Joined: Sep 2003
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Have you ever looked for the resistor at the column base?
Does the clutch switch work as expected? EVERYTIME? Maybe you bypass (jumper) it for diagnostics.
Most of the modules I see on eBay even the ones that mention a KEY CODE ain't actually KEY DECODER MODULES.
You might consider looking further into your issues. I'd be sure that if you consider buying you make sure it's pinned like this in one of Cliff's posts.
https://www.corvetteforum.com/forums...post1581212461
Security light has nothing to do with your issue.
You didn't mention having the FSM. Do you?
Last edited by WVZR-1; Oct 10, 2017 at 08:32 AM.
Thread Starter
Heel & Toe
Joined: Apr 2017
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I believe that the mechanic replaced the ignition with a non-VATS ignition (Is that possible) ? It isn't a hot starter issue. I suppose I could check the Clutch Switch. I would have to wait for the no crank issue to happen, and then quickly do that test. Is it easy to do ? Do you have a link somewhere that described how to check the Clutch Switch ?
I don'r have the FSM.
I have seen where people have a chip made to totally bypass the VATS. Is that an option ?
I do have a performance chip in it now.
I don'r have the FSM.
I have seen where people have a chip made to totally bypass the VATS. Is that an option ?
I do have a performance chip in it now.
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Team Owner
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NO - not an option.
Clutch switch as well as resistance required for crank generally either work or don't. A 15 minute wait for clutch switch is a NO. A simple check of clutch switch might be KEY TO CRANK (1st) then depress clutch occasionally to see if it enables CRANK. You need to be sure that the CLUTCH SWITCH isn't bypassed also, use neutral with no one or nothing close. In the link I provided you for the module I've no idea how the usual 4 minute delay to reset is controlled.
The FSM might be a wise buy.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
The delay is done by the VATS module. Don't try to start it over and over again and make sure to wait at least 5 minutes. Each time you try and fail it resets the delay timer.
Safety Car
Joined: Aug 2013
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From: Minneapolis Mn
If your security light is blinking, yes I believe you have something going on with the VATS system. IIRC if you have a VATS start failure (typically due to either the resistor or clutch switch failure, it's about a 15 minute reset).
The easily accessible items are the clutch switch and the key resistor.
The key resistor can be overridden by using a dongle. This is overridden by disconnecting the twin wire connector coming from the column (1 wire is orange IIRC) and at the connector disconnect it and plug the correct dongle into the end going up behind the DIC. The clutch switch is up by the pivot on the clutch pedal. Unhook the connector and jumper the wiring connector.
At this point you've overridden both of the 'usual' issues. When you enter the car and turn the key on the Security light should be out. If it's on you have some other issue going on. If it's out, when you should hear the fuel pump run for a few seconds once the key is turned on. You should be able to then start the car if all else is working.
I have read where others have bypassed the remaining items in the VATS system but I do not have any info on that procedure.
Good luck.
The easily accessible items are the clutch switch and the key resistor.
The key resistor can be overridden by using a dongle. This is overridden by disconnecting the twin wire connector coming from the column (1 wire is orange IIRC) and at the connector disconnect it and plug the correct dongle into the end going up behind the DIC. The clutch switch is up by the pivot on the clutch pedal. Unhook the connector and jumper the wiring connector.
At this point you've overridden both of the 'usual' issues. When you enter the car and turn the key on the Security light should be out. If it's on you have some other issue going on. If it's out, when you should hear the fuel pump run for a few seconds once the key is turned on. You should be able to then start the car if all else is working.
I have read where others have bypassed the remaining items in the VATS system but I do not have any info on that procedure.
Good luck.
Team Owner
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If the OP's failure is an EVERY TIME occurrence then maybe there's a component in the module responsible. Not knowing how the OP's mechanic did the by-pass it's difficult to speculate. He needs to look.
I've never used a bypass for anything but diagnostics(I have an Interrogator) but perhaps if maybe one of the New Rockies or other similar was used it's that module that's failed. I've never had a hands on or seen the install instructions. I've seen 555-timer VATS module builds mentioned but never used one, I always thought that when you used one of those you actually bypassed the SER so you would have CRANK any time key was rotated.
Last edited by WVZR-1; Oct 11, 2017 at 07:39 AM.
Team Owner
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I don't believe "CRANK RELATED", VATS (Vehicle Anti Theft System - YES) BUT I'm reasonably sure that it (SECURITY LIGHT) is only a component of the forced entry for early C4.
Last edited by WVZR-1; Oct 11, 2017 at 08:12 AM.
Racer
Joined: Apr 2017
Posts: 396
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From: Katy Texas
I would start simply by checking that both battery terminals are clean and tight. I had the exact same problem on my 89 and it was a loose dirty positive terminal bolt. Was allowing just enough current to turn on the dash but nothing else. A pair of new terminal bolts were a few bucks.
Safety Car
Joined: Aug 2013
Posts: 4,427
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From: Minneapolis Mn
You are correct, I should have said security instead of Vats here. I had some issues with mine when I bought it. One was apparently it wasn't reading the resistor on the key all the time (figured that out later), when you turned the key on the Security light was flashing and the starter wouldn't engage. Once I put a resistor dongle on the car that part of the issue went away.
Thread Starter
Heel & Toe
Joined: Apr 2017
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What is the Vehicle Anti Theft System Module ? I see them for sale on ebay. Could that be the issue ? Also, is the a way to check and see if the key bypass is working ? Still stuck here with intermittent no-crank.