I just bought a 1987 Chevy Camaro Iroc Z, the 5.7L V8, this past month. Ran good for a week or so and now its been in the shop for the past 2 weeks. The check engine light comes on after the car has been driven for 5-10min. It will then stay on until you turn the car off. When you start back up, the light will stay off until 5-10min of driving again. OBD1, diagnosed as a code 12 which either shows up as "no codes saved" or "ECM Error". Had 2 mechanics look at it at this point and neither one can sort it out. Had the ECM examined and its fine.
Recently replaced:
*Distributor
*Fuel Pressure Regulator
*Thermostat
*Cooling Fan Wiring
*Radiator
*Spark Plugs

I'm at a loss for what to do about this. I planned on having this car as my daily driver and I don't know that I can get it smogged like this. And more than that, I just want to know what the heck is going on. Any ideas?

 

Lack of communication to the ecm, Although tested good it's sounds bad. The 127165 circuits boards crack. A tap test while running to see if that makes a difference. Or just replace the ecm and check the ground behind the passengers side cylinder head.

 

O2 Sensor...

 

A overly rich or lean condition the ECM would throw a code. A lazy or dead o2 stuck at .450mv would cause the engine to have poor fuel economy and not go into closed loop.

 

Not to be mean or anything, but, that car is officially an ANTIQUE in most states. It isn't the sort of car you need to buy if you intend to daily-drive it but have to pay somebody else to work on it. You better be made of cubic $$$$ if you intend to pull that off.

Now's a great time to set aside "pay" and "have done" and "2 mechanics" and all such as that, buy a few tools, and learn to take care of stuff like that yourself. With the help you can get on this site you should easily be able to get it done. AHELLUVALOT EEEEEEZIER AND CHEEEEEEEEEEPER than paying some "mechanic" to swap out a bucketload of "maybe it's this maybe it's that bust out yer checkbook".

 

You definitely need someone to put a decent diagnostic tool onto your ALDL port and look at the real time values.
This could be so many things, beginning with faulty sensors and ending in defective wiring.
How is the car handling itself once the SES light is on? Rough idle? Poor performance or fuel economy?

 

Yeah, you need to see the live data. Could be the engine coolant temp sensor reading way hot. Ohm the sensor at operating temp. Should be around 200 ohms.

 

http://www.ebay.com/itm/like/121601381757?lpid=82&chn=ps
Get one of these. Plug your laptop into your OBD1 Port, and look at the datastream through TunerStudio or something. You should be able to see what the issue is.

 

I second that.
Tested a cable from aldlcable.com once, which can be set to work with every kind of third gen, and it worked perfectly with TunerPro and the right files.

We can go into that in more detail, should you get yourself an ALDL cable.

 

another thught on the antique thing....cant you possibly register it as one, and not worry about smog?