Hmmm, sometimes too much or too complex info muddies the water?? Early on, you advised that your o2 was only switching to 0.5v, rather than 0.1 to 0.9. By the way, I don't know what brand of o2 you used for your replacement - the Bosch is considered one of the best (they invented the o2 sensor).
Glad you finally got this sorted, and fingers crossed for your test...

 

You're right about that. Part of the problem was that, early on, I didn't trust my ability to use the scanner correctly and I certainly was hesitant to trust the salvaged ECU I put in. It was ironic that the up stream O2 apparently failed in the middle of solving the IAC problem. I initially wanted to blame the switched ECU for the bad readings on the O2.

Oh, well. I've been fooled by crafty vehicles before such as the time I did rod bearings in a '55 Chevy with the engine in the car. When I got the pan back on, I ran it for a while, got out to look underneath and stepped in a puddle of oil. It was leaking around the front end of the pan so I pulled it and re-did the gasket. That didn't help. When it was running, there was steady stream of oil dripping off the pan. I called a friend to help me put the gasket in right the third time. He declared the dripping oil smelled like transmission fluid. We finally found that there was a tiny crack in a cooler line which sprayed a nearly invisible jet of fluid into the frame in front of the engine where it was washing out the accumulated sludge from years of valve cover and front seal leaks. The motor oil/trany fluid combination which dripped off the front of the pan looked like motor oil, felt like motor oil but smelled like trany fluid. A new piece of tubing took care of that.

Anyway, I appreciate the help on this one and will post the results of the smog test tomorrow. ... Malcolm

 

Bosch it was, cost too much to pay shipping both ways for replacement... New one delivered was cheaper...

... Philip

 

Forgot to mention I used NTE (NKG) O2 sensors.

 

Good luck with the smog. Hopefully you will post back with your 'passing' results....

 

IT PASSED!!!

Everything looked really good except the HC at 15mph was 57 with a max allowable of 58. That's something that might be a problem the next time around or maybe it's just where the system holds it and won't get any worse. I have 2 years to think about it.

Thanks again for everybody's help. ...Malcolm

 

I must say, I opened this thread to read your latest post with just that slightest bit of trepidation!!
Well done!!! I'm really glad that you got this sorted (and, in the end, pretty easily too). As an added bonus, you also got more familiar with your electronic equipment. I must admit that I used to skim over all of that stuff when reading these posts.....

 

When you have time to spare

High HC Emissions

Inoperative/missing catalytic converter
O2 sensor malfunction
Internal engine problem
Vacuum leaks (hoses, vacuum operated devices, intake manifold,)
Ignition system malfunction (plugs, plug wires, points, dwell, etc.)
Improper fuel injector operation
Incorrect ignition timing and/or idle speed
Incorrect air/fuel mixture
Defective EGR valve or air injection system failure


Also, must make sure the Engine and CAT are hot when running SMOG...

.... Philip

 

The engine recently started idling a little rough in gear (not bad, but enough to shake the transfer case shifter) even though it's at the correct RPM. There may be a connection.

Inoperative/missing catalytic converter - downstream O2 is new and steady
O2 sensor malfunction - probably not at this point
Internal engine problem - will do compression check
Vacuum leaks (hoses, vacuum operated devices, intake manifold,) - have done a propane test.
Ignition system malfunction (plugs, plug wires, points, dwell, etc.) - plugs are new but don't know about wires, Will check the whole ignition system
Improper fuel injector operation - possibly. Put injector cleaner in today
Incorrect ignition timing and/or idle speed - both read OK
Incorrect air/fuel mixture - hope that's no longer an issue
Defective EGR valve or air injection system failure - computer likes the EGR and it is clean

 

Start with the compression test. Everything else depends on the foundation of proper engine timing.