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87 No start. Need help! Long!

Bluesbrother

Active member
Joined
Aug 12, 2003
Messages
28
Location
Lowell, Michigan
Corvette
in between
History: 42,000 mile auto, vert, 3rd owner. Last year it would sometimes not start. I would rack the shifter a few times and it would start. The car sat over the winter and I did some engine cleanup, new plugs, plug wires, distributor cap, rotor, coil. I also installed new valve seals and roller tip rockers.
Early May I get things all back together and try to start. Acts like the solenoid is not kicking in. I buy a the best battery NAPA has as I am not sure of the age of the old one. Same problem. I clean all the connectors behind the battery and look in the engine compartment for loose connections. I pull/push on everything that is visible. Same problem. I jack the car up and see that in order to get to the starter I must drop the X brace in able to drop the Y pipe in order to get to the starter. At the same time a family member dies and I just don't have the time or energy to devote to the problem. I tap on the starter solenoid as best I can. Now when I turn the key I get nothing except a click from the driver's side engine bay near the power brake booster. Racking the shifter does no good. I give up and have it flat-bedded to the local garage. They test the VATS system and find that my key and the ignition cylinder is OK and it is sending a signal to the VATS decoder module. They give up and tell me I need to take it to a Chevrolet dealer as the dash will have to come off and they show this as a 7 hour job!
I just flat-bed it home. Funeral is over and I can get back to my life. I get out my Corvette GM service manual and its electrical supplement. I search for others with the same problem and find that there is a TSB on replacing the ignition lock and keys. I don't trust the local mechanic any more so I decide to replace the ignition lock cylinder and keys. I ordered them from Corvette Central and have the keys cut at Sears. They use their machine to confirm that my new key pellets match the resistance of the old ones. I replace the ignition lock and put everything back together. Nothing except the same click from the engine bay. I jump A and B and only get a code 12.
Yesterday I removed the upper dash pad, breadbox and the other things I need to take off in order to get into the guts of the dashboard.
The electrical supplement to the GM manual says I should test the Starter Enable Relay and the VATS decoder module.
I am weak on electrical knowledge. I bought a digital multi meter but I have never used one.
Here are my actual questions: 1. The VATS Decoder Module test says to measure voltage at VATS Decoder Module Connector (Disconnected). "Measure between S(PNK/BLK) & Ground with the correct voltage being "Battery" while the ignition switch is set to "Run". Do I stick the meter's probes into the disconnected "male" part of the plug or do I plug the harness into the module and stick the probes into the designated area?
2. When it says the correct voltage is "Battery" what does that mean? 12 volts?
3. Further down the test sequence it says to check the individual wires for an "open". How do you do that and what does open mean?
4. Further down it says to connect a fused jumper from a terminal to ground. What is a fused jumper? Do I solder one of my spare mini fuses to a length of wire with alligator clips at each end? If so, then do I use a "10" or "25" fuseor what?
Thanks for any advice. I am trying to get my car to Bloomington Gold at the end of June and am really stressed that I will not be able to get it started by then.
Any other words of wisdom are greatly appreciated!!!!!!!!!!!!
 
No longer need help! I followed the directions in my GM Service Manual and found the problem to by my VATS Decoder Module. As soon as the local GM dealer opens on Tuesday I will see if they still carry these.
 
AT7ragtop said:
a click from the driver's side engine bay near the power brake booster. Racking the shifter does no good. I give up and have it flat-bedded to the only get a code 12.
Which, you know means that the ECM is in test mode, with no codes.

AT7ragtop said:
digital multi meter
FWIW, the digitals use much lower current than the old analog meters, which is safer with electronic devices.

AT7ragtop said:
The VATS Decoder Module test says to measure voltage at VATS Decoder Module Connector (Disconnected). "Measure between S(PNK/BLK) & Ground with the correct voltage being "Battery" while the ignition switch is set to "Run". Do I stick the meter's probes into the disconnected "male" part of the plug?
Disconnected, check the voltage in the plug, not the component

AT7ragtop said:
2. When it says the correct voltage is "Battery" what does that mean? 12 volts?
Yes, nominally. The battery, fully charged, holds a shade over 13vdc (volts, direct current). This is not meant to be a precise measurement.

AT7ragtop said:
3. check the individual wires for an "open". How do you do that and what does open mean?
Wih the DVOM (digital volt-ohm-meter) set to a low setting, say 200 ohms, or perhaps a notch up, look for "0" or a very low reading when one DVOM lead is connected to one end of the wire in question, and the other end connected to the other end. An 'open' means the wire is not continuous; not allowing electrical flow, due to some sort of a break. Check for voltage on the wire before doing this. You don't want to have it powered by anything other than the meter itself.

AT7ragtop said:
4. it says to connect a fused jumper from a terminal to ground. What is a fused jumper? Do I solder one of my spare mini fuses to a length of wire with alligator clips at each end? If so, then do I use a "10" or "25" fuseor what
I doubt that fuse size is not so important here, or they would specify a size. Actually, I'd lean towards a 10 vs larger, to protect any component. Either fuse would blow if there is power at the tested lead, when the fused lead is connected to ground. You might want to use a fuse holder and the old glass fuses, in case you need to replace a blown fuse. Soldering directly to a fuse lup could prove tedious, if oft repeated.

Good luck. I hope this gets you started (no pun....oh, what the heck!)
:w
 
AT7ragtop said:
No longer need help! I followed the directions in my GM Service Manual and found the problem to by my VATS Decoder Module. As soon as the local GM dealer opens on Tuesday I will see if they still carry these.
Well, great! Perhaps you can run with it out of the circuit, but I do not know how to bypass it. Perhaps a search on "VATS defeat or bypass", or such, might turn something up.

Actually, here's two:

http://www.corvetteactioncenter.com/forums/showthread.php?t=65613&highlight=VATS+bypass

http://www.corvetteactioncenter.com/forums/showthread.php?t=62819&highlight=VATS+bypass

:w
 
some of the vendors sell a VATS bypass module. you might want to search for this and just bypass it.
 

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