Hello all,

My 99 corvette base model 6 speed has been on jacks since November. I replaced the exhaust system, clutch, pilot bearing, slave cylinder, rear main seal plate, and rear axle seals.

Prior to this work, my vette was having some electrical issues. For starters, my passenger window/lock switches stopped functioning. Soon after that, I notice my fuel gauge and temperature gauges were not reading correct (pegged to one side). I started to get 'reduced engine power' and other messages and lights. My turn signals also stopped functioning completely. The car was starting and driving fine (besides my slipping clutch).

Fast forward to now. I have everything back together and my car will not start. It will crank and crank but no fire. I have never had an issue getting it to start. I have noticed my ignition relay is buzzing. I also notice my fuel pump will not prime. I jumped the fuel pump in the fuse box and it will kick on but the car still will not start. I replaced the fuel pump relay and it still won't prime! My dash is showing the same messages and the same gauges are being weird. I cannot pull codes with my basic code reader as it says it cannot communicate with the vehicle.

I am getting fuel when I jump the fuel pump. I am getting spark and air... I have cleaned the contacts in my ignition switch assembly. I have cleaned all grounds... I have read there may be a voltage issue between the ignition and the ignition relay...

I am eager to get this thing back on the road so any insight will be appreciated!

Thanks

 

Ignition relay buzzing means the relay is not getting full battery voltage across its coil. Sounds like the car has a seriel data buss highway problem, it could be a bad module or even bad connections in the connectors between the doors and car. There are two connectors by the BCM that contain metal jumpers thar connect the communications wire to each other, you can remove those metal jumpers on both connectors and place a wire that will connect the bcm and pcm only, I unfortunately do not know what color the two wires are, search on this site and you can find that out.

 

Do you know for sure that you are getting spark? Have you verified fuel pressure at the rail? Both should be pretty straightforward to check. If you hear the fuel pump kick on then start with verifying spark.

Also sounds like you have quite a few electrical gremlins to work out in various systems.

 

Yes verified spark and fuel at fuel rail. It has to be electrical which is not my strong suit lol

 

Codes?

 

My tool won't connect... cannot communicate with vehicle. I bought this car last march and it came with a GM diagnostic tool and an old laptop. I am going to fire that up and see if it can give me some info

 

Crank or Cam position sensor maybe? Does it stumble or just suck air? If you have spark then I can't see how it would be related to the ignition circuit. If you installed a new fuel pump relay and it won't prime without jumping then I would start with that circuit.

Reading codes would certainly help narrow it down.

 

The fuel pump prime is controlled by the pcm which provides a ground to the fuel pump relay. If as you stated that you are not very knowledgeable in the electrical aspects of a car, I would find a shop that specializes in automotive electrical repairs.

 

So I have my tech2 reader connected and it will not connect with the vehicle. Is this because I have a short in the ignition circuit?

 

The reason the reader can't connect to the car is because the seriel highway data buss is not functioning. The c5 has one wire that all modules in the car communicate with each other, you will have to find out what is causing the data buss to be down.

 

If you can’t connect with your scan tool you most likely have a serial data bus issue…the car will either be a crank no start or a start and stall…if you are weak in electrical best to take the car to an auto electric shop !!



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