OK I dont know if I did something wrong but my last thread didnt post. I have a 93 Vette (my first) and I have a list of problems.
1) a/c heater control does not work, back light is on but no LCD
2) it idles low even when its cold
3) it has a slight back fire when I get on it
4) more often then not my speedometer goes out or goes heywire then "sys" flashes

I love my corvette but its to where I want to trade it in. Any help would be appericated

 

Your desire to replace the car will be replaced with pride in a job well done when you've got her the way you want her.

1) I think there is a ZIF connector that can come off. Pull the head unit and eyeball it. I bet it's something easy. This thread has the details. (clicky)

2) At what RPM does it idle? Is it an auto or a 6spd?

3) Does the backfire occur when you let off the pedal or when you press down on the pedal?

4) My first thought is an intermittent ground.

Does your car have any stored codes?

 

Thanks for the reply. I'll pull the head unit out this weekend. Its auto trans and it idles around 400-500 rpms even when I first start it up. It back fires when I step on the gas. I'll have to get it checked out for stored codes.Thanks again I'll let you know what I find this weekend

 

Check out your own stored codes by following this guide. (Clicky)

Ok so we've got some unburnt fuel/air making it past the cylinders.

The TPS could be sending bad data to the comp. Forum search TPS.

Air could be getting into the exhaust. Check for exhaust leaks and the integrety of the large air hose going to the left manifold.

One or more cylinders isn't firing. Ohm out the plug wires. If any wire's value is way off from the others it needs to be replaced. Pull the spark-plugs and compare them to any of the many spark plug diagnosis charts found online or the last page of every Chilton book.

Ignition advance isn't happening or is happening too slowly. Bad Opti

One or more injectors isn't opening/closing as quickly as it should. With a mechanic's stethescope listen to each injector. They should all sound the same. (Yes I know that many use Noid lights. But they only tell you that the injector is getting a pulse. They tell you nothing about the size or duration of the pulse. Oscilliscopes do a much better job of looking at the pulse.)

An O2 sensor is sending bad data to the comp. I don't think you've got one sending no data because that will make the SES light come on.

Check all vacuum lines for cracks etc.

Do the analogue and digital guages for oil and coolant temp agree with each other? They may be off from one another a bit but check for readings that are way off.

 

Ok I had to do the Army thing these past few days. I finally got a chance to pull the ac/heater control. I cleaned the connections, checked the wires and even took it apart to clean and check connections. It still dont work and now the speedometer is blank!!!!!!!

 

I did a search about the "SYS" flashing light on the dash a couple of weeks ago. Most of the responses were to replace your battery when you get this message. I went ahead a replaced mine since it was around 7 years old, and I have not seen the "SYS" flash since I replaced. Good Luck with the repairs.