Hi, Well this car is starting to drive me a little crazy!! I changed the CTS - had code 14 - and the thing next to it. Replaced all the little vacuum lines, new distributer, new PCV, new wires and plugs. Also any hoses that looked bad.
Soo you would think it would at least run the same but it's not.
I took it in to be smogged yesterday and it passed without a problem. The engine light has stayed on since the code 14. When it starts up, it idles at 400 rpm's it was at 700 rpm's before the CTS. It also runs rough and kinda bucks changing gears.
There aren't any codes and I don't have a clue what to check at this point. I almost forgot, when I drive it sometimes the light goes out and it runs fine but as soon as the light come back on it runs rough.

Help please!! It's a 1984 Z28 with 305 automatic.

Thanks in advance!!

Judi

 

Judi,

The '84 systems are a little different, a little slower, and a little less reactive than the newer models. Still, the basic operation is hte same. When you scan for error codes, you should at least be getting a "12" repeating. Is that what you are seeing?

If you have no stored error codes, and still get the MIL, your "12" may be indicating that the ECM is not getting distributor reference pulses when expected. That could be the fault of a connection, pickup coil, HEI switching module, or reluctor problem (all in or at the distributor). Double check the distributor wiring, clear the ECM, and try again.

 

Yes, I am getting the code 12. I will check out the stuff you have listed tonight. Thanks!!

 

Well I didn't get a chance to check out the things you listed! I got half way home and the car really started acting up The idle was bouncing all over the place, but the gauges didn't change. I stopped at a light and when I stepped on the gas, it reved up to 35000 and wouldn't shift out of 1st gear. I parked the car and smoke -kinda white came out by the firewall.
Soo I had it towed to the house and don't have a clue

 

maybe you messed something up when you did your tune-up. I'd check your fireing order and timing. if its not shifting you have a huge-normous vaccum leak somewhere, which would explain the crappy running too.

 

Smoke from the firewall area? Near the back of the passenger side head maybe? A bad ground connection/strap could cause all your symptoms, and it just happens that there is a very important ground strap that runs from the passenger side head to the firewall.

 

I couldn't tell if it was the passenger side or by the carb. I do know that it was back there somewhere. The brakes (power) also acted funny, hard peddle but it didn't want to stop.

 

You might want to start looking for vacuum leaks. Hoses, the EGR valve, PCV valve, and power brake booster are common suspects.