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OldCadTech

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Everything posted by OldCadTech

  1. No need for the snide professor comments! I'm not a professor, never claimed to be a professor. I simply understand the system as I attended a LOT of GM classes and diagnosed and worked with "it" when this was current model year technology. I stated I didn't want to do a thesis on BL and fuel integrator because the information is available all over the WWW as you have already found out for yourself. There are a total of 32 cells. When you're ready to do the injector o-ring leak test it will tell you more than watching the integrator and BL values.
  2. No, if you disconnect the battery, the BL adjustments default to 128 (the neutral value for BL is 128). Another name for BLOCK LEARN is long term fuel trim. There are more than one BL value, unlike the single Integrator. There is a table in the ECM EPROM (chip) that gives VE ( Volumetric Efficiency ) for a given RPM and MAP condition. It is more of a "formula" to achieve a 14.7 A/F ratio. The ECM tries to maintain 14.7 to 1. The reason is, 14.7 A/F ratio allows a catalytic converter to reduce exhaust emissions most efficiently. Engines don’t run the best at 14.7 all the time, but they produce the least emissions with a catalytic converter at this ratio. Also, the standard O2 sensor is most accurate at a 14.7 A/F ratio. The O2 sensor does not actually measure oxygen concentration, but rather the difference between the amount of oxygen in the exhaust gas and the amount of oxygen in air. ... Lean mixture causes low voltage, since there is an oxygen excess. In your O2 sensor picture the left bank is LEAN and should look more like the right O2 sensor, not Exactly, but closer to it. I didn't want to write a thesis on long term and short term fuel trim or block learn and integrator values. Keep in mind that this type of fuel management control is 25 year old, old school technology. Now, there are pre-cat O2 and post-cat O2 sensors, ECM/PCM's processing much more information and adjusting fuel mixtures faster than you can imagine.
  3. This is a very basic, hopefully easy to understand definition. There is a whole lot more to it.
  4. The fuel integrator is what the ECM is commanding. The block learn is that the left bank is trying to enrich the mixture and the right bank is is trying to lean the fuel mixture. It is running off a pre-programmed "block" of parameter information to perform that task.
  5. The one on the left should look like the one on the right. The right one is slightly rich but probably because of the A/fuel ratio imbalance. I would concentrate on the left side first. You could, possibly, pass a DEQ test BUT I doubt it. I think the low speed test would do you in. But I've seen stranger things happen at DEQ test stations. You won't get a current E046 on a cold start cuz the system has to be in closed loop.
  6. Lean fuel mixtures cause high NOx. A lean fuel mixture exists when less fuel than required is delivered to the combustion chambers or when more air then necessary is added to the fuel. Very distinct possibility of injector O-ring cracking and leaking, I'm thinking it is sucking TOO much air, BUT yes, a dirty or plugged injector will cause the same problem. To verify, spray carb cleaner or brake cleaner around the injectors and see if the rpm's rise. If the rpm rises change the injector o-rings.
  7. Basically, it chemically breaks down / softens the seals - see barczy01's post above for the final result. Better to stop using it now and hope for the best.
  8. I think you are spot on. Hard to tell, and I'm not familiar with the tool either but it looks like "Cylinder A" was tapered a lot more than "Cylinder B"... If you can post a pic of the tool and model number or a reference to their website I'll see if I can figure out the readings.
  9. I would fix the EGR system and clean the T-body first. Then, put some miles on the vehicle if you can without getting pulled over. It's about a 10 minute cycle for the cross counts to set the E046 so drive it for 10-15mins if you can. Retest the O2 sensor response cross counts again, and see if they wake up or improve. Wouldn't hurt to do a few "hard accelerations" either to help "push" them out of bed.
  10. Yes, probably needs a new EGR and gasket. Before you buy the new EGR, remove the old EGR, leaving the gasket as it was when you removed the valve. Make sure the pintle opening is not plugged with carbon first. If it is plugged, clean it real good with carb cleaner. After it is clean, lift the diaphragm by hand again and watch the pintle, if it moves okay by hand, apply vacuum to it and again, make sure it moves freely. If it passes all those tests and the intake port is not plugged, re-install it, run the engine again and retest it. If you lift it this time and the engine still continues to run. then the intake manifold MAY need to come off and be hot-tanked. Cross that bridge when you get there.
  11. My only concern is, it is on the bottom of the range. If it was me, I would check base timing and if it was okay, I'd dial in a couple of degrees of advance and see where the needle points after that. Do you have a timing light? They're a little archaic now but I think Sears still carries them. If you do have a timing light, there is a method to put the PCM in set timing mode and there is a special wrench that makes loosening and tightening the hold down bolt a breeze, so let me know before you try to make any adjustments to the timing. The bolt is a 15mm head machine screw. You can use a crows foot wrench on it but it takes a swivel ( universal joint ) & an extension and it takes a bit of finesse. Lets move to the EGR valve for a minute. To check the EGR operation you will possibly need a mighty-vac, hand vacuum pump. The first check is to check if the pintle can even be moved. With the engine at idle wrap your fingers around the valve and "lift" the diaphragm, the engine should die. If the diaphragm will not move, Replace the EGR valve and gasket. If it stays running replace the EGR valve and gasket. If it dies, you will need to apply vacuum to the valve. IF you don't have a hand vacuum pump, you can disconnect the vacuum line from the vacuum gauge, leaving the adapter connected at the #91 fitting. Plug the line with a golf tee or whatever will work, start the engine, remove the plug and cover the hose with your finger. Momentarily connect it to the EGR vacuum port. do this as quickly as you can keeping the vacuum leak time as close to zero as you can, and the engine should die. If it stays running or simply runs rough replace the EGR valve. In the picture above the diaphragm is the silver looking plate above the brass colored brace. Let me know what happens
  12. That's pretty good, a little on the low end but not too ba. When you say fairly steady how much fluctuation was there? Here is a more detailed chart, which one is the closest to your condition?
  13. Sorry, NO quick fix for the head gasket. The "fixes" out there are all snake oil. See post above... Repair will be closer to the $5-6000 by the time all the necessary items are replaced. Cost to repair exceeds cost to replace.
  14. You can fit vacuum hose inside a larger vacuum hose and it will seal, but it has to be a tight fit. The best place is to disconnect the vacuum hose from the # 91 fitting and connect the vacuum gauge there but it requires an adapter like the one to the left of the gauge and hose in the vacuum gauge picture above or several different sizes of vacuum hose, the hose is cheap.
  15. You need that vacuum line connected, that is why you need the T and another piece of hose, so you can "tap" into the line. Unless one of the other nipples has a cap on it, then you can connect directly.
  16. You will need some different sizes of vacuum hose & you'll have to do a little plumbing if it is threaded. Disconnect the elbow from the line and use the long side of the T in the line, hook the gauge into the short fitting. Yes check the vacuum first...
  17. The other thing I kept forgetting and was going to mention a long time ago before I got side-tracked on the E046 is that the emission test failure for NOX is more likely an EGR problem. Remove the egr valve and make sure the ports are clean and not restricted. The E046 and a restricted or plugged vacuum port could all be related as well. There are vacuum passages under the throttle body that are infamous for plugging also.... How's that for confusing the issue?
  18. You can get some vacuum hose and a "T" fitting and connect to 102 or, if the other ports above it are capped off remove the cap and install the vacuum gauge there. The gauge will fluctuate like the picture on the bottom row in the middle...
  19. That is a probability, but, due to the fact both of them indicated 0 cross counts, I'm thinking more likely a fuel injector problem or a vacuum leak. It could still be an O2 sensor but don't throw parts at it until you run out of money. If you have a vacuum gauge, install it and note whether the needle is steady or fluctuates, what is the reading at idle, how does the engine react if you snap the throttle, what is the reading and how does the needle react at a steady 2000 rpm? See the attachment...
  20. The one on the left under econ, it indicates the engine is running in closed loop. The flow chart wants to make sure the engine is running in closed loop before proceeding with the trouble tree. Basically, Open loop means the PCM is running on a block learn or a preset group of engine parameters and is ignoring the O2 sensors until they should be hot enough to operate correctly and the engine no longer needs a richer mixture, such as when the engine is cold. Closed loop is when the PCM is using the data from the O2 sensor to control fuel mixture. There are a LOT of variables such as block learn, long and short term fuel trim and integers. Way to much detail for a code like this. Please take note of the " Likely causes of an E046" in the FSM, you need to be certain that all these possible causes are RULED OUT before proceeding with the E046 trouble code flow chart. The FSM is assuming NONE of those conditions exist, otherwise the test is NOT valid.
  21. What was the status of the auto light on the A/C control panel? Cross counts are the number of times the sine wave signal ( in this case it is O2 sensor voltage ) crosses a base line voltage per second. The PCM uses this "count" to determine fuel/air mixture. For example a "lazy" or slow O2 sensor would not cross the base line a given number of times in that second. So, if the PCM wants to see the signal cross the base line 5 times a second and it is only crossing 2 times in a second, the PCM detects that as a problem. Looking at the flow chart it appears the PCM is looking for something above 3 for normal operation.
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