Completely STUMPED!
Thread Starter
Heel & Toe
Joined: Jan 2012
Posts: 22
Likes: 0
From: Aubrey TX
Completely STUMPED!
Man...being car-less for a week kind of sucks. All because the '91 refuses to start! I don't get it!
The car was running just fine last week, it's my daily driver. Sometimes it does this weird security system lock on the engine or something where it won't let me start the car, but I just unhook the battery and plug it back in and it works.
This time it doesn't. I turn the key and no click, no nothing!
There are the normal lights on the dash and I just got a new battery yesterday...still nothing.
Any suggestions...?? THANKS GUYS!
-If it is a VATS problem, how do I know?
-I just changed out my heating core last month, maybe that did something?
The car was running just fine last week, it's my daily driver. Sometimes it does this weird security system lock on the engine or something where it won't let me start the car, but I just unhook the battery and plug it back in and it works.
This time it doesn't. I turn the key and no click, no nothing!
There are the normal lights on the dash and I just got a new battery yesterday...still nothing.
Any suggestions...?? THANKS GUYS!
-If it is a VATS problem, how do I know?
-I just changed out my heating core last month, maybe that did something?
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
http://troubleshootmyvehicle.com/gm/...tarter-motor-1
If it cranks but does not fire then you have a VATS problem
Have you got a spare key to try, the resistor pellet wears with age and does not make good connection with the contacts in the key barrel ( which also wear out )
http://www.thirdgen.org/vats_passkey_system
If it fires up when the starter jumped then it is not VATS but a starter circuit problem
Starter enable relay or the P/N switch at base of the shifter would be 1st things to check
The relay and switch are easily bypassed by jumpering the connector to confirm if faulty
Could also be a faulty Ign switch
If you have no cranking at all then likely the starter is faulty
Last edited by vetteoz; Feb 22, 2013 at 07:53 AM.
Race Director
Joined: Feb 2003
Posts: 16,475
Likes: 270
From: Kingman AZ
Cruise-In VII Veteran
Cruise-In VIII
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
Sometimes you can clean the key off with alcohol then slide it in and out of the switch a few times to clean the crud off the switch.
Probably won't work but who knows?
I had an 87 that did the same thing. I had the FSM and followed the testing procedure to find out I had a bad VATS module in the dash. Got a good used one from Vette2Vette and had no trouble since then.
I have a 91 now and have the FSM for that too. If you shoot me a PM I can copy the "no start" page(s) and e-mail them to you.
Probably won't work but who knows?
I had an 87 that did the same thing. I had the FSM and followed the testing procedure to find out I had a bad VATS module in the dash. Got a good used one from Vette2Vette and had no trouble since then.
I have a 91 now and have the FSM for that too. If you shoot me a PM I can copy the "no start" page(s) and e-mail them to you.
Race Director
Joined: Dec 2000
Posts: 17,551
Likes: 26
From: El Paso Texas
Hot wire the starter direct to the battery and see if it fires up ( key on )
http://troubleshootmyvehicle.com/gm/...tarter-motor-1
If it cranks but does not fire then you have a VATS problem
Have you got a spare key to try, the resistor pellet wears with age and does not make good connection with the contacts in the key barrel ( which also wear out )
http://www.thirdgen.org/vats_passkey_system
If it fires up when the starter jumped then it is not VATS but a starter circuit problem
Starter enable relay or the P/N switch at base of the shifter would be 1st things to check
The relay and switch are easily bypassed by jumpering the connector to confirm if faulty
Could also be a faulty Ign switch
If you have no cranking at all then likely the starter is faulty
http://troubleshootmyvehicle.com/gm/...tarter-motor-1
If it cranks but does not fire then you have a VATS problem
Have you got a spare key to try, the resistor pellet wears with age and does not make good connection with the contacts in the key barrel ( which also wear out )
http://www.thirdgen.org/vats_passkey_system
If it fires up when the starter jumped then it is not VATS but a starter circuit problem
Starter enable relay or the P/N switch at base of the shifter would be 1st things to check
The relay and switch are easily bypassed by jumpering the connector to confirm if faulty
Could also be a faulty Ign switch
If you have no cranking at all then likely the starter is faulty
Bingo.Follow that, and all will be revealed.
Burning Brakes
Joined: Jul 2012
Posts: 826
Likes: 3
From: Seabeck WA
Man...being car-less for a week kind of sucks. All because the '91 refuses to start! I don't get it!
The car was running just fine last week, it's my daily driver. Sometimes it does this weird security system lock on the engine or something where it won't let me start the car, but I just unhook the battery and plug it back in and it works.
This time it doesn't. I turn the key and no click, no nothing!
There are the normal lights on the dash and I just got a new battery yesterday...still nothing.
Any suggestions...?? THANKS GUYS!
-If it is a VATS problem, how do I know?
-I just changed out my heating core last month, maybe that did something?
The car was running just fine last week, it's my daily driver. Sometimes it does this weird security system lock on the engine or something where it won't let me start the car, but I just unhook the battery and plug it back in and it works.
This time it doesn't. I turn the key and no click, no nothing!
There are the normal lights on the dash and I just got a new battery yesterday...still nothing.
Any suggestions...?? THANKS GUYS!
-If it is a VATS problem, how do I know?
-I just changed out my heating core last month, maybe that did something?
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Burning Brakes
Joined: Jul 2012
Posts: 826
Likes: 3
From: Seabeck WA
Melting Slicks
Joined: Apr 2007
Posts: 2,616
Likes: 111
the more I read about the VATS, the happier I am that I have an 85; not that it is the best of the C4 clan, I understand; plenty of upgrades with the later years. But with all the other common issues these old cars experience, I am glad that is not on my "what if" lists. But from what I understand, it can be programmed in the ECM to bypass the VATS system.....It seems the likelihood of VATS failing is far superior to our $5K cars being stolen....
Also, I like fact I have worry free anti-lock brake issues! The car stops fine w/o it with a well maintained brake system; but then again I don't autocross this thing : and that god-forsaken third brake light
There is just no way to make the third brake light attractive IMHO....
sorry to get sidetracked.....slow news day
Also, I like fact I have worry free anti-lock brake issues! The car stops fine w/o it with a well maintained brake system; but then again I don't autocross this thing : and that god-forsaken third brake light
There is just no way to make the third brake light attractive IMHO....sorry to get sidetracked.....slow news day
Team Owner
Joined: Aug 2004
Posts: 21,543
Likes: 3,216
From: Park City Utah
If you have other issues, (as Vetteoz accurately stated), a "VATS bypass won't fix anything.
Team Owner
Joined: Dec 2000
Posts: 21,094
Likes: 282
From: Phila., PA burbs
All the VATS bypas does is install a resistor into the same circuit that goes to the resistor pellet in the key anyway. So "VATS Bypass" only works if the problem is in the harness running up the column, or the contacts in the tumbler/key. All easy things to diagnose and fix.
If you have other issues, (as Vetteoz accurately stated), a "VATS bypass won't fix anything.
If you have other issues, (as Vetteoz accurately stated), a "VATS bypass won't fix anything.