asilverblazer

Check the rubber brake lines for internal collapse. However, extreme uneven wear should be coupled with a noticeable pull while braking, that one would expect a driver to report. Check the side that is not wearing out; it may not be getting brake pressure forcing the 'bad' side to do all the work and wearing out prematurely. Make sure all the guide pins are properly lubricated. Make sure when replacing pads to replace and lubricate the pad guides as well.

Spacer height does not equal lift height. However I doubt they can achieve 4" of lift using the methods you describe, see more below. This is anecdotal information. Trucks do typically sit higher in the rear, 2" measured where? The way you describe the lift is sounds like a fairly common "leveling" style lift that raises the front by adding spacers the make the strut assembly taller. Nothing is being done to correct the ball joints operating at the limits of their travel. A heavy duty ball joint will not fix this either. Which you discovered the hard way apparently. A new upper control arm can correct the upper ball joint angle issue, but still nothing has been done for the lower ball joint. EDIT: I see that the kit included upper control arms, that should correct ball joint operating angles. It sounds like your upper control arm failed and not the ball joint. That is a TrailFX problem for sure. I still doubt gaining 4" lift using the parts... unless you add the front and rear amounts together. Regarding the front, the only other 'beneficial' items added are the diff spacers to correct cv-shaft/joint angles and/or length. It sounds like your truck should be pretty close to the amount of factory rake based on your combination of parts. I would expect about 2.5-3" of lift in the front and that is give or take the same amount you added in the rear. A set of rough country blocks would net the same lift and been a whole lot cheaper. https://www.roughcountry.com/product/gm-leveling-lift-kit-1307?utm_source=google&utm_medium=cpcs&utm_campaign=18887230045|&utm_content=&utm_term=||c||fit_first_1307-a&gad_source=1&gclid=CjwKCAiAudG5BhAREiwAWMlSjFaqDbEtdfjz8nJZC038lpZieFgwfHwyEcG3JxoWJGuARA5CX6a0qxoCaa0QAvD_BwE https://www.roughcountry.com/product/lift-block-ubolt-kit-6532?utm_source=google&utm_medium=cpcb&utm_campaign=17867436380|&utm_content=&utm_term=||c||fit_first_6532-b&gad_source=1&gclid=CjwKCAiAudG5BhAREiwAWMlSjDUxINhV5Ukf-0qOhn5QwVghwSaCt6w5Q7NMEIsGHThPG9lmwRJD-BoCRGMQAvD_BwE You can venmo me the $900 I just saved you!

The truck can detect a miss fire by anomalies in the crankshaft rotation speed. Each cylinder fire introduces a pulse to the crank shaft rotation, these pulses each correspond to a cylinder known to the PCM by the firing order. A missing pulse means that cylinder didn't fire. The PCM doesn't know why it didn't fire. Other clues OBDII codes might suggest other anomalies if they are strong enough to trigger. A lean condition might indicate lack of fuel from a failing injector or too much air from a manifold leak. A rich condition may exist from a lack of ignition of the injected fuel.

I think its just different terms for the same action.

All makes sense to me here. At WOT it should be going to power enrichment mode, looks like it is describing it as an 'open loop due to engine load'. STFT go to 0 because it is using them - not sure if the LTFT at 5% is normal or not. This situation is the condition that throws everything out of whack, apparently after 10 seconds or so of WOT I think cylinders 1, 4 and 8 start leaning out, O2 voltages drop and miss fires increase. Depending on which error the VCM picks up first determines how the VCM reacts. I recall something along the lines of the low O2 voltage tests don't come up if active miss fires are present. This might explain how restarting may or may not result in improvement of condition. "Status 16" I bet is because of the low O2 volage... from the lean condition that caused the miss fires. Initially the lean condition wasn't present, so the VCM was fine with what the O2 sensors were reporting. Running at full throttle for an amount of time before things start getting lean might be a helpful clue, versus not immediately being a problem when you give it full throttle. Fuel delivery is pretty simple, fuel pump, filter, injectors. You have considered the fuel pump and monitored pressure and noted that it never faltered, so we rule it out. With miss fire conditions isolated to a few cylinders it seems that injectors would be most suspect. A faulty injector could just be 'tiring out' with the demanded heavy use compared to instantly stopping... Being able to run an amount of time at WOT might also indicate the fuel pump is not up to snuff, as the need for more fuel 'continues' and fuel that was present in the lines gets used the pump can't replenish it fast enough. I would carefully watch your fuel pressure gauge to see if it tapers off at all during WOT. I think the more likely problem is the injectors - but it could be a slight combination of the two. I wouldn't consider it yet... for the same reasons you state, in addition to why would that cause isolated problems on 1, 4 and 8?

I don't think a HPFP would only cause problems on a specific cylinder. Did you swap plug and plug wires from a good non missing cylinder? Good ignition, good fuel... inspect everything from the cam shaft to the valves. Take a look here:

I'm pretty sure I'm following everything with you, and I think the conclusion of fuel injectors makes sense too. Everything is fine and is confirmed by the logs until you need full power, power enrichment, lower AFR, or simply an injector duty cycle (fuel amount) that they cannot achieve (deliver) that results in lean condition that causes other problems... I might be inclined to say that you don't need to replace all 8 injectors because of the miss firing only occurring on some cylinders. A full new set would probably be just as easy though. Its what I would do.

I posted something similar in another thread, if you can't readily determine the problem, run it till you can.

Have you followed the diagnostics in this section? Reading through points to many of the same things we are talking about... wiring conditions, unmonitored air in the exhaust... Also, noted that miss fires will interfere with this codes test cycles. I didn't see it but it implies to resolve the miss fire condition first. Notice that injector balance test is included. I may be incorrect in my above idea that there are two separate issues. It could be that one problem is presenting itself to the computer in two ways. So, I posit this, it could be that there is a lean condition at cylinders 1, 4 and 8. Lean enough at times to trigger the low voltage code, but not so lean to cause a miss fire. Looking forward to what you find during that diagnostic.

Unfortunately, this is really at the limits of my knowledge of understanding log data and potential problems with the data set. A wired scanner, would eliminate some of those possibilities, to what end I'm not sure. For simplicity sake, looking only at the data that doesn't appear questionable might be easiest. Also, there are essentially two things that are known. Low O2 voltage and miss fires (1, 4 and 8). What progress can be made by not looking at the data? What does you FSM suggest for diagnosing the Low O2 voltage? Does anything in the FSM for that diagnostic path correspond with the random miss fire diagnostic path? I wouldn't focus on that yet, might be pulling timing because of the above conditions. I can posit a condition where the timing is occurring too late and leaving an incomplete combustion causing a low O2 reading... I expect the fix to be much more simple than the diagnostics, the miss firing cylinders might lead you to the O2 voltage issue. Assuming a quick check of the ignition, compression, fueling of those cylinders doesn't reveal anything, then a more in depth inspection might reveal something causing the O2 reading issues; something like an intake manifold leak, exhaust leak, etc. You might also while in that process find a wiring issue that explains the data problem and O2 sensor issues. Another option, reach out to a competent tuner that looks at data logs everyday, Justin at Blackbear is the go to on this site.

Yep, there should be a bumper there. Torsion bars aren't typically 'adjusted'. But the years and mileage on the rig may have caused them to settle/wear some. There is a specification for adjustment - 'z-height'. It's not a very intuitive measurement to take. The easiest method, is to measure from the bottom of the lower control arm bolt to the ground and record the measurement. Measure from the rear lower control arm mounting bolt to the ground and record the measurement. The difference between these two is the 'z-height'. Refer to your factory service manual and confirm my measurement points because I might be remembering them wrong. It should also specify the measurement. Torsion bar adjustment will require an alignment afterwards.

Sooooo, I think there might be two issues. 1. There are some data issues - I see some instances where the O2 sensors stop reporting, I think this causes the fuel trims to a 'default' setting. This might be 'open loop'. Short term fuel trims go to 0 and long term stagnate. These 'gaps' in O2 data might be a wiring issue where the PCM doesn't get information from the O2 sensors. This triggers the low O2 sensor voltage. It could also be that the circuit that powers the O2 sensors is cutting out. This problem will cause its own drivability issues. The short term fuel trim goes to 0 when the AFR is in power enrichment. It does seem to get 'stuck' example at line 629. The long term trims stop fluctuating as strongly. In fact, the rest of the drive looks like what ever happened at this point never resolved. Line 1085-1595 looks like the engine was off. Line 1620 short term fuel trim comes back on, not sure why. If you take out the data below line 630 - everything looks reasonable. Only miss fires on cylinders 1 and 4. This is roughly the first 10 minutes of your log/drive. So what happened? Loose wire connection? Maybe a power or ground cable? I would typically be hesitant to say the PCM is the problem, but it might be worth considering. EDIT: It could be that the O2 low voltage code triggers the PCM to stop referring to the O2 data and subsequently stop using short term fuel trims. If the O2 low voltage happened at around line 617 then the rest makes sense. Line 617 - 630 should have been a power enrichment event but the long term fuel trims are using a pretty weak enrichment amount compared to the drive so far. Long term trims are adding up to around 20% but at power enrichment it is only adding 2-3%. Engine also goes lean at this time (low O2 reading). Why is the long term fuel trim so weak at this data point? 2. Miss fires are still occurring on cylinders 1, 4 and 8. Miss fires are reported on other cylinders but its a small fraction of what are reported on 1, 4 and 8. Probably because of issue 1.

I think you haven't corrected the original problem, you've only fixed the bad O2 sensors. The generic O2 sensors weren't the original problem but might have exaggerated it. A bad coil wouldn't cause miss fires on only three specific cylinders. It sounds like the original and lasting issue is the miss fire(s) that you can focus on now. Regarding the cap and distributor, again my luck was not good with it. Cap replacement was essentially a yearly maintenance item. Moisture and corrosion would build up inside it on the terminals. Also, the screw to hold the cap down stripped out so it wouldn't stay on securely. The easiest tests/checks I'd do would be the cap inspection and wires followed by a new log. A change in miss fires conditions should be readily apparent.

After looking at the latest log, everything looks like I would expect it too. O2 sensors are reporting, fuel trims are adjusting and it looks like everything is doing what you expect. I didn't see the obvious lean condition at WOT either. That's the GOOD NEWS! However, you're still getting miss fires on cylinders 1, 4 and 8 and none on the others, appearing to rule out a fueling issue, air intake issue, exhaust, vacuum leak, etc. I think that is good news too. As isolated as the miss fires are I would suspect an issue specific to the problem cylinders. I don't recall if a compression check was done, but do so to rule out valve issues. That leaves ignition. I never had good luck with rotor caps on that generation of engine, I would inspect that for sure. Including for 'corrosion' on the underside at the terminals and on the rotor tip and top at the coil to rotor terminal. The problem cylinders are also next to each other in firing order - is the cap on securely? I've also had bad plug wires new out of the box. If you still have the old ones, try an old wire on the problem cylinders to see if the miss fire counts drop with a different wire. What codes are you currently getting? FYI: I'm looking at the data in excel and applying conditional formatting to the columns to better see lean vs. rich conditions. When the PCM commands power enrichment (11.5 commanded AFR) the O2 sensors should show rich. Also, as MAF reading increases so does fuel flow. Dips in O2 voltage (lean) have a corresponding bump in short term fuel trim (adding fuel).

Looking at the latest log, it is still running lean at WOT. Log only included bank 1 upstream and downstream sensors. Bank 2 wasn't logged. Fuel trims are still doing some weird things in the log... its looks like they stop responding to anything. At WOT, presumably during power enrichment and it appears to be only during power enrichment, it runs lean. A log of no WOT and only applying 80% throttle might confirm this. Can you log injector duty cycle? I'd like to see what the injectors are doing vs. being commanded when these lean conditions appear. A custom tuner would probably be better able to recognize oddities and problems. EDIT: Can you log fuel rail pressure?

You probably ran the battery down. Not sure why you are looking at the speakers if you didn't mess with them. Check the door switch, sounds like it isn't breaking continuity when it should. Without knowing what all connections you messed with changing out lights its hard to know what could have gotten 'mixed'. In any case, make sure the ignition switch is off, the light switch is off, dome/map light switches are off and doors are closed. There should be no draw on the battery in this state. If the battery keeps going dead, you're going to need to learn to use a mulit-meter and see whats on.

The torque converter not locking is contributing to additional heat in the transmission. This may or may not be related to the throttle body... What was the problem and diagnostics related to replacing it? What are the present symptoms? Full vehicle information? Repair history? Other relevant information?

Sounds normal to me with no load on the engine or transmission.

Easy fix then.

Under warranty? If so, the good news is if its getting worse, you eventually won't have to guess what is making the noise. I know - not real helpful - but sometimes I have used the approach that if you are reluctant to TRY something and hope it fixes it, it doesn't hurt to wait for the problem to manifest itself in a manner you can more confidently diagnose. Some might say this is opening yourself up to worse damage - so is tearing open a transmission to find nothing wrong $$$.

Doesn't seem likely, can you look inside and see any obstructions? Can you compare new parts to the old ones? Will the old ones install?

I think the source of the noise is the transmission. The question remains if it is normal or not. I think the very specific speed (it downshifts to a lower gear or up to a higher fear outside of the speed range you indicate) of the noise is due to the gear the transmission is in - to confirm or test, try putting the range selector in manual and when the noise is occurring select a gear higher or lower. I would also suggest a fluid flush as a maintenance item - and it might help the noise too.

This won't fix a miss fire. Its an old thread, but there is documentation to visually inspect for other problems that the truck can detect as a miss fire that are nothing of the sort. It listed items such as tire out of balance, accessory drive belt problems, road imperfections, bad motor mounts, etc. The point being that the knock sensor can 'feel' some abnormal vibrations and assume it is an engine miss fire.

Looks like you need to check the wiring - check resistance/continuity between point a to point b. Look for obvious problems frayed or pinched wires.

Cables could be corroded inside the insulation. Try running an auxiliary ground from the engine to the frame and battery terminal.