O2 Sensor Voltage? Reply #15 – July 05, 2010, 09:19:25 PM Best I can remember the black ones are for a CFI application...Assuming you are getting a KOEO, remove the sensor and depress it approx 1/8" while running codes to see if the 34 is eliminated... Quote Selected
O2 Sensor Voltage? Reply #16 – July 05, 2010, 09:47:26 PM Quote from: TurboCoupe50;327397Best I can remember the black ones are for a CFI application...Assuming you are getting a KOEO, remove the sensor and depress it approx 1/8" while running codes to see if the 34 is eliminated...Will do Tom. After installing a mini starter on it today, I didn't have time to to test the EGR control valve, but I did have time to test the TAB & TAD's. I disconnected their pigtails and used a 12 volt jumper to make sure they switch and they did. The diaphragms don't leak in them either, so they're good.I also wanted to test their wiring, so I did another KOEO test. After the last code was thrown, I pushed the gas pedal briefly to WOT. After doing that, I went around the car to the TAB and TAD and probed them both to make sure they had 12 volts coming to their input terminals. They both did which was good. I then went back around the car and pushed the gas pedal to the floor one more time and let off. I then walked back around to the TAB & TAD and probed to see if I had 12 volts at the output terminals. I did, so my TAB & TAD are good to go!One thing of note though Tom, which might help me resolve what the issue really is with the Thermactor system on this car is this. When I did the KOER test this evening, the EEC not only threw the 34 code like it has always done, it also threw a code 81. A code 81 designates a bad diverter valve. The definition of a code 81 doesn't waiver in its description like other codes. I plain out reads that the diverter valve is bad. I'm still gonna test it before replacing it. The diverter valve should be easy enough to test like the TAB & TAD were, so that's no big deal.I think we're closing in on wrapping this up Tom. I'll test the EGR control valve tomorrow like you said and let you know what I found. After we've resolved this, I should be able to offer some good help to anyone on here with Thermactor problems. It looks like I'm gonna have tested every component in my Thermactor system before all is said and done!I LOVE that gear-reduction starter by the way. I like the way it sounds better than the one that came with the car. Vinnie was right. The thing does make my car sound like a Chrysler starting up! Quote Selected
O2 Sensor Voltage? Reply #17 – July 06, 2010, 09:15:16 AM Ok Vic, if depressing the EGR sensor while running codes eliminates the problem, you can "shim" the rod with small vacuum cap on the end and reinstall it... If I remember correctly, the black ones have a resistance of 0-4500 ohms while the grey ones are 0-3000 ohms... Highest resistance is at rest so if you depress the plunger, it will be similar to the correct sensor... I had the same code 34 problems on a '86 Grand Marquis and I believe wound up using the black sensor with the cap on the plunger... Been 12-14 years ago, can't remember for sure... Quote Selected
O2 Sensor Voltage? Reply #18 – July 06, 2010, 12:17:15 PM Quote from: 88 Blackbird 5.0;327320On another note... I replaced the O2's today. After I replaced them, I reset the base idle. After the base idle was reset, I did another KOEO test as well as a KOER test. The KOEO test threw a code 34 again and the KOER test threw a code 34 and a code 44 (thermactor system fault). Functional O2 sensors are required for the KOER test to look at the AIR system. If you have an O2 code, the EEC won't test AIR during KOER. Quote from: 88 Blackbird 5.0;327229The passenger side O2 sensor I tested today must be bad, because it didn't react at all (no voltage output from it) when I tested it with the engine running in closed-loop.Oxygen sensors normally fail lean. i.e. They fail to create voltage and the EEC reads that as a lean condition. The EEC will then richen the mixture as far as it can, but give you a 41/91 code. The 42/92 code is odd as it didn't match what you measured at the sensor. Quote from: 88 Blackbird 5.0;327413When I did the KOER test this evening, the EEC not only threw the 34 code like it has always done, it also threw a code 81. A code 81 designates a bad diverter valve. The definition of a code 81 doesn't waiver in its description like other codes. I plain out reads that the diverter valve is bad. I'm still gonna test it before replacing it. The diverter valve should be easy enough to test like the TAB & TAD were, so that's no big deal.The 81 code is a solenoid test, not a valve test. Valves are tested in KOER.Tangent:The following is my guess at how the AIR tests are run. Once the EEC sees that the O2 sensors respond to rich/lean conditions, the AIR tests are run. The only way the EEC can test the system is to look for a lean condition when the AIR directs air to the exhaust manifold (upstream of the O2 sensor). So, the EEC first tests directs the TAB/TAD to activate and send air to the exhaust. If the O2 doesn't go lean, you get a 44/94. The system doesn't (and can't) know what failed, it just knows there wasn't any response from the O2 sensor. Somehow, no (or not enough) air was sent into the exhaust.Weak AIR pumps, borderline O2 sensors, and borderline A/F control can all cause 44/94 codes. If you only get a 44 or a 94, then you can normally rule out the valve, as at least one side passed the test. Next, the EEC tests the TAD/TAB solenoids/valves individually. You can look at the picture and apply some logic to figure out what can cause certain codes. A 45/95 (Right/Left AIR not diverting) is caused by the diverter valve stuck being open WHILE the bypass valve functions properly. A 46/96 (Right/Left AIR not bypassing) is caused by the bypass valve being stuck open WHILE the diverter valve functions properly. Quote Selected
Well... Reply #19 – July 06, 2010, 01:16:53 PM There's no need to try pushing down the pintle Tom. When I went out and checked to see if the EGR control valve was switching, it wouldn't switch. I grounded the negative terminal and the valve still wouldn't let any vacuum through. Luckily, my other T Bird had a good EGR control switch on it, so I put it on this car. I haven't had a chance to clear the codes and do another round of KOEO and KOER tests, but I'm pretty sure the EEC won't throw a code 34 anymore now that I replaced that inoperative EGR control valve.On another note, when I tested the TAB and TAD valves today, to see if they were still switching, The TAB tested fine, but the TAD failed. It's bad. Since the TAD controls the diverter, that HAS to be why the EEC was throwing that 81 code. Later today, I'm gonna sneak out to the garage and see if the TAD on my other T Bird is good. If it is, I'm going to put it on the Blackbird and see if that stops the EEC from throwing the code 81. I bet it will.That's really good info Jeremy. That chart really does break down how the system works. I might make a copy of it and keep it around for future reference. Quote Selected
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