Regarding the vacuum hoses: I created and maintain a thread on replacing them for my 1999 with a 4-button transfer case. Here is the link: https://blazerforum.com/forum/2nd-ge...replace-95425/ (I also have it in my signature below.)

 

Thank you that was the post I was having a hard time finding again. Is that just the hoses for HVAC and the transfer case or is that really the entire system? I want to just go through and replace all the lines to start fresh.

 

Yes, those are all of them for a 4-button transfer case and HVAC. I can't think of any others. Well, there is an elbow for the PVC valve and for the crankcase ventilation tube where it attaches to the TB air inlet too if you want to count those. I was in the same boat as you wanting to have all of the hoses I could find to be new.

 

That log file is hardly readable. But as far, as I can see (correct me if I'm wrong) amongst the thousands of the data stored into the cells, Your fuel trims are about +-5%, which is acceptable. That means there should be is no leaking spider nor vacuum. The RPMs are not listed. What's Your idle rpm value? Did You get any other error codes?

P.S. As to the LIM gaskets I didn't mean not doing them at all. Time is short, so we have to prioritize. Do important things to pass the survey. Then OP may do the LIM gaskets, together with a lift and other things.

 

I don't have state emission testing in Indiana, but as I understand it in a lot of states they allow one emissions readiness test to be incomplete (but not failed).

For repairing the codes, have you found the OBD2 index yet on this site? There is description of exactly what has to happen in order for the code to be set. A lot of times that can be a big help. https://blazerforum.com/forum/tech-a...agnosis-26408/

I assume you had a p0506 or p0507. From the link I referenced immediately above...…. A slow, unstable, or fast idle may be caused by a non - IAC valve system problem that cannot be overcome by the IAC valve. Out of range control IAC scan tool counts will read above 60 if the idle is too low and zero if the idle is too high. So it follows that if it idles within 0 to 60 counts on the IAC, then it's happy enough and no problem is currently being observed.

Question I have is if you still have current codes or not and what they are. Do any come back if you clear them at this point? Maybe you just whacked out the MAF sensor for a while by cleaning it?

Here's some select PIDs from my own 2001 blazer for you to compare to (taken a long time ago). One is at idle in drive. The other is going down the highway steady at moderate speed. Note IAC retracts to about 200 counts when driving. Then controls around 100 in drive at idle. I don't know what counts would be in park. I assume something less than 100 but maybe not as low as 60. I would assume that if any vacuum leaks causing high idle, then counts would be low.

 

The code I get, and that returns after clearing is :P0507. That is what displayed after the MAF and TB cleaning and is still there after the IAC and TPS replacement.
My idle after warming up and in drive will sit about 700. The noticable thing about the idle is it will hang about 1200. While trying to do the GM drive cycle coast portion, I can let of the gas and it will get to 1200 RPMs and it will stay like I have cruise control on. if I brake it will of course slow down but the idle tries to stay at 1200 making the downshifts very jarring/clunky. After the clunky downshifts and I stop completely the idle will slowly settle back down to the about 700RPM area.
The O2 code I got, and has since not returned after a clearing, I forgot to write down however I did pull the below test while I had that code.
Test report:
------------------
TID:$02 CID:$04
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$10
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$11
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$12
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$20
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$21
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$26
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$30
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$31
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$36
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$40
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$46
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$06 CID:$35
- Lean to Rich sensor switch time(calculated)
Max: 74
Test result value: 33
PASS
----
TID:$06 CID:$47
- Lean to Rich sensor switch time(calculated)
Max: 210
Test result value: 72
PASS
----
TID:$06 CID:$55
- Lean to Rich sensor switch time(calculated)
Max: 73
Test result value: 30
PASS
----
TID:$07 CID:$0c
- Minimum sensor Voltage for test cycle(calculated)
Max: 0
Test result value: 56,320
FAIL
----
TID:$07 CID:$0d
- Minimum sensor Voltage for test cycle(calculated)
Max: 155
Test result value: 56,320
FAIL
----


End of report.

 

The code is the P0507 and it continues to return. Are those shots using Torque? I am new to this end of Torque, I only used it for checking code before. I found the RPM, Baro, and MAF selection but if they are from torque can you let me know what heading they put those other dials you have under so I can get the same screen shots and report back?
Thank you

 

My shots are using Car Gauge Pro. I do know Torque Pro pretty well too.

In Torque Pro you need to add displays into a realtime info screen. Make sure you have GM Enhanced PIDs enabled in the settings. I would use "small" or "tiny" digital displays, and limit the number appearing on a single screen unless you want jerky displays. 30 scans/sec split between 6 PIDs give you only 5 updates/sec. If you have a slow adapter (I once had one that was 3 scans/sec), you can get pretty jerky displays. Torque Pro will do pretty much the same PIDs that Car Gauge Pro and Dash Command with GM Enhanced PIDs will, but torque Pro won't do the cam sensor retard. Use the GM PIDs whenever possible. You will need to search through the PID list to find each PID that you want to use - they are named accordingly and appear after you select Digital Display. You should start seeing GM at the beginning of the names after a couple of page downs if you have enabled the GM enhanced PIDs.

Here's something important that I don't think many people realize. Below are plots of O2 sensor voltage, the first at idle and the second at 2000 rpm. Notice that the voltage cycles up and down past 0.45V, even though the instant readings captured are 0.74V and 0.13V respectively. Also notice that the cycling frequency is much more rapid at higher RPMs. All this means is that the system is controlling fuel mixture and the instant readings on the O2 sensor serve absolutely no purpose (unless they stay 100% above or 100% below 0.45V). The fuel trim is what can tell you if you are running lean or rich, by comparing the pulse width of the injectors to that programmed into the PCM by the factory. A fuel trim of ±10% of factory settings is acceptable. Mike can fill you in on this more! I just wanted to throw out the plots to illustrate that O2 sensor readings captured by scanners actually mean very little.

If the O2 sensor voltage stays above or below 0.45 volts without cycling, then the system recognizes a fault and sets an O2 sensor code. Seems to be what you captured previously in post #26. Does that mean the O2 sensor is faulty? Contrary to the local parts stores - not at all, the O2 sensor may very well be reading just fine and is only telling you that the system can't control like it is supposed to. That's when you get out the factory manual and go through the diagnostic chart to determine the problem (which can be many things). But first need to make sure the problem is really there and identify it better.




.

 

Well I spent the better part of the early afternoon getting and replacing all the vacuum lines christine_208 had posted. There were definitely some that were deteriorating and probably cracked. The one of the vacuum reservoir broke and I had a hell of a time getting the pieces off of there from behind that ABS block and under the fender but I think I got it all and the new hose back on. The going to the HVAC behind the front bumper was the worst, that basically crumbled in my hand. I did not get to the fuel spider today, and may hold off from your recommendations at this point. I also put a new PCV valve in today just for good measure but the old one moved freely.

After getting all the vacuum lines done, the codes were cleared by me taking out the battery and tray to get to the 4x4 vacuum hose. So I took it for about a 15 mile ride and just a few minutes in the high idle code returned and the idle issues coming to a stop and the faux cruise control were still there.

This trip also came with two new interesting things. The first is an issue, which is the A?C compressor was turning on when the selector was on vent only. I know I need to do some A?C checking later as the compressor cycles on and of very quickly when it is on the A/C selector, but this was with the dial beyond the A/C selection and just on the upper vent, blender down to full cool and fan on 2..checked it did it at any speed as well. I then moved the selector to the Max A/C position, verified it was rapidly cycling as it usually does, then switched it back to upper vent only and the problem seemed to have gone away for the time being.
The good thing that happened on the way home was that the Secondary Air System test that was the only one that would not switch to complete for SMOG, is now showing complete. I am not familiar with the system and how it works perhaps vacuum had something to do with that? In either case it is complete, now I have to hope that the other will complete now even with the Idle Fault Code which was not happening when I actually had all those tests completing before.
Also and additional side question I can't find a replacement gasket for the upper intake. The orange one that slides over the TB. Not on any OEM parts sites that I can find. Is this not sold or only sold as part of a set or component?
Thank you

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Added info, and well it is also not the MAF sensor. Picked up a new Delphi today and it fired right up and it at first seemed the idle was better but then I ran it around the block and I still get the clunky down shifts and the pull feel of a 1500rpm stall converter. The high idle code is sticking around as well.