I have had the worst time every with my 93 Z28 and I can't seem to get anything figured out. I just took the vehcile to a repair shop for them to do a diagnostic on it and they actually called me and told me they knew there was a problem but they couldn't figure out what it was and for me to come pick it up and pay nothing! AHHHHHH. So if someone out there can help me I'd greatly appreciate it!!!!!!!

I had a catalytic converter fire that melted a the shifter cable and the O2 sensor wire. I replaced the CAT, cable and O2 wire. Then the mess started.....I replaced the battery, alternator, ignition module, ignition switch, coil, optispark distributor and cap & rotor, spark plugs, plug wires, starter, fuel filter, and O2 sensors. Plus I checked the fuel pump which is doing good. The car will not pass California Emissions (SMOG) as it failed with over twice the allowed crap. The car will randomly die and takes forever to start back up as it just cranks.

The most interesting thing is that the volts at the battery are in the mid 12's when the car starts and is running normally the volts are in the 14's when running. When under full load the volts drop back to the 12's. However, when the car starts to screw up the volts drop down into the low 11's even to the high 10's at times. Plus the battery guage is just at or a little below the mid way point when problems occur. What could be causing this when almost all electrical parts are replaced.

I need to know why the car dies, why it is running rich on fuel, why it fails smog!?!? All problems occurred at the same time. PLEASE, ALL SUGGETIONS ARE APPRECIATED!!!!

 

Sorry, I forgot to mention that when the check engine light comes on and I go to check it I can no longer figure out the codes because the light will not blink anymore. Which just started happening a week ago.

 

If the check engine light comes on, there should be stored codes. Even if the light is no longer on.

 

Sorry, I didn't explain the check engine light problem well enough......being that I have a 93' I have to read the codes by watching the light blink and count. The problem is that the light no longer blinks. So I dont get a code 12 or anything else! Why would it stop that all together as well?

 

Eh, I though you could still read codes w/ a 93, the light blinking was a diagnostic thing...Maby I'm wrong.

 

Th only way I have ever known to read codes was the light blinking. Is there another way since it just stays solid and doesn't blink now.

 

I just figured out the flashing check engine light problem. (blown fuse) But I was able to retrieve two codes. 46 & 53. Chiltons Manual says 46 is faulty circuit from ignition switch to theft deterrent module or ECM. 53 is system voltage high: will set if the voltage at the ECM is greater than 17.1 volts or less than 10 volts, check charging system. So i assume the volts were way to low considering all light dimmed and the car died! Suggestions?

 

Fpr might be bad. I replaced the coolant temp sensor in the water pump and fixed my dying problem.

 

If you are having electrical problems check the grounds. If you burnt the O2 sensor wires I would double check the grounds on the passenger side of the block. If I remember right (check on Shoebox's site for locations) the is a ground going to the passenger side motor mount.
You might also change the main wire from the alternator to the battery. I bought an 18" pre-made cable and ran it from the alternator to the distribution block insetad of back to the battery.
Just my 2 cents.

 

I just checked all the grounds and everything seems to be in order. I have no idea what else to check. Any ideas? All suggestions are appreciated!

 

Is it possible when the fire happened you burned any other wires? Any other burned fuses?
If you can get the car scanned (I don't know how on a 93 - freescan won't work) and see what is actually happening. It will give you a better idea of what is going on.

 

well i know i burnt the wire to the O2 sensor and the shifter cable for the transmission. But every other wire in that location is good condition. All fuses visibly checked out good too. As far as a scan, I took it to one shop already who told me to take it to a specialty electric shop. However they want an arm and a leg just to tell me what is wrong with it! I can do all the work myself, I just don't know what to look for or work on next!

 

Find someone with a scanner that can read your 93 - I have an AutoXray that will read up to 2002 (and all the way back to the early OBDI). An alternative is to find someone with a Tech2 (most dealership mechanics have them) and ge some real time data. You might want to put your location in your sig - there are a lot of local members that you would never know about. You might want to post a request for someone with a tech2 on the Southwestern section with the location - it might cost you a 12 pack but you'll know more than you did.

 

Not a bad idea!!! I just changed my sig to show my location. But I'll give your suggestion a shot and she what I can find!