Car Won't Start - The Puzzle

[Jack B]

I was getting ready for the drag racing in Columbus and performing a few tasks on my 97 GTS:

1. Changed spark Plugs.

2. Did a compression test - it was very good. To do this I attached the remote starter switch at the starter.

3. Changed the drivers side O2 sensor because it seemed to be getting a little lazy. To change it I had to lift the ground wires off the frame right below the PCM.

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I went to start the car and it cranks strong, but, will not start. Here are some observations:

A. I removed the battery negative terminal for ten minutes to reset the PCM

b. The key fob appears to arm/disarm the security system without issue.

c. The fuel pressure is perfect.

d. It is not getting spark or fuel. Plugs are dry and there is no spark at the plug wires.

e. Scan tool shows no DTC's or any issues. Most of the PIDs seem normal with the key on.

f. Checked all the PCM connectors and the injector/coil pack connectors.

g. Checked all the obvious fuses.

h. Flopped the ASD and AC relays.

I. The vec2 lights up and gives the signal for new card acceptance.

j. The voltage shown on the scan tool is good.

Can anyone solve the puzzle?

 

[mjorgensen Woodhouse]

It is easy to get a voltage spike to the RKE module that controls the anti theft module. The arc from the battery terminals can be enough to do this. It more often than not will only fry a portion of the module making it hard to diagnose the real problem, I would start there myself.

Mark

 

[Steve-Indy]

Feel free call me... or e-mail me your phone number or e-mail address...or, I can e-mail you mine.

 

[mjorgensen Woodhouse]

Feel free call me... or e-mail me your phone number or e-mail address...or, I can e-mail you mine.

Mark Jorgensen
[email protected]
800-889-1893 just not this week ;-)
402-677-2935 cell

 

[dave6666]

Mark Jorgensen
[email protected]
800-889-1893 just not this week ;-)
402-677-2935 cell

DAVE
1-800-GET-BEER (wk)
1-800-GOT-BEER (hm)
[email protected]
Budwieser, TX 12345

 

[Steve-Indy]

Jack B ???

 

[99 R/T 10]

Even though you didn't touch them, might want to check to see if there is any problems with the MAP, Crank or Cam sensors.

 

[Viper Wizard]

Maybe he's driving? Jack, is there something to post?

 

[Jack B]

Maybe he's driving? Jack, is there something to post?

The puzzle is solved. It became more interesting before the problem was found. My scan tool showed no codes and it appeared all the sensors were working. I put the car on the trailer and took it to a dealer who had a DRB. He could not find anything either.

As I stated earlier I removed the ground wires from the G100 stud below the PCM and then put them back in place after I installed the O2 sensor. The ground stud is 5/16" diameter, therefore, you can get good torque on the stud. After the car did not start I removed the ground wires and re-torqued them at least two more times and the problem did not change. That stud has the PCM ground from the factory. I had added the VEC ground and two additional device grounds.

I tried re-torquing them again, but, this time I sanded both sides of the four ring terminals, bolted them back down and it fired right up. What was strange was the fact that there were no codes and the PCM seemed to be working fine. It is so hard to believe a little copper oxide could create such an issue. I also used a liberal amount of dielectric grease over the stud and terminals - this was the wizards recommendation.

I did find an interesting issue with the service manuals. I checked the PCM battery (2) inputs to verify it was getting power. The Powertrain diagnostics manual says those wires are in C1 and the 97 service manual says they are in C3. They were in C3 which is the connector that is the furtherst forward.

Thanks to all that passed on their input, the car is running great and the new O2 sensor fixed the rich condition on the drivers side bank.

 

[GTSnake]

That's really strange. I would have never guess that was the problem. If it cranks then how could it be the ground? Does the starter use a different grounding point?