Fixed! Chevrolet Lumina with loss of power on hills

Car model and year: 97 3.1 Lumina has 90K

Symptom:

a bit of a very slow coolant loss, and the pump was found leaking. Replacing that, about a month ago, it started having a loss of power between 20-40 mph. I took the car and found misfire codes on cylinders 2, 4, 5, and 6.

What I did:

I cleaned the MAS, replaced the spark plugs and wires, checked all the coil-packs with a spark tester (they checked out with strong spark), and checked the fuel pressure at the fuel tube that feeds the injectors . With that done and the problem persisting (especially when the car warmed up to operating temp), I had Cottman transmission (very reputable guys at this local shop) and they checked it out and found the same engine codes, but stated the transmission was working fine. During the next few weeks, another noted very slow coolant leak was detected without anything leaving the engine. During this time, possibly unrelated, I had problem starting the car and found the battery had developed a bad cell, but the alternator checked out, so I replaced the battery. Anyway, knowing the 3.1’s storied issue with the complicated factory head gaskets leaking coolant, I took the large task and replaced the head gaskets and had new valves and seats installed in the heads. it is much better, but still noted she felt there was still a lack of power on the hills.

Chevrolet Lumina scanner to use and test results:

Foxwell NT301scanner: not idea
I did get a Foxwell NT301 and saved some running data.

Here’s an example of one of the “printable” moments that the Foxwell recorded, there are well over 50 pages:
Calculated Load Value(%)14.9
Engine Coolant Temperature(øC)93
Short Term Fuel Trim -Bank 1(%)-6.3
Long Term Fuel Trim – Bank 1(%)-2.3
Intake Manifold Absolute Pressure(kPa)71.0
Engine RPM(rpm) 1893
Vehicle Speed Sensor(km/h)20
Ignition Timing Advanece for #1 Cylinder(ø)-1.5 Intake Air Temperature(øC)51
Air Flow Rate from Mass Air Flow Sensor(g/s)36.42 Absolute Throttle Position(%)43.9
Location of Oxygen SensorsB1S12–B2S—-
Oxygen Sensor Output Voltage Bank 1-Sensor 1(V)0.045 Short Term Fuel Trim Bank 1-Sensor 1(%)-3.9
Oxygen Sensor Output Voltage Bank 1-Sensor 2(V)0.105 Short Term Fuel Trim Bank 1-Sensor 2(%)N/A
OBD requirements to which vehicle is designedOBDII

Just test drove her again and got the error code:
PO102
Mass of Volume Air Flow A
Circuit Low

I replaced the MAF a few days ago. So I remeoved the new plastic one and replaced it with the original aluminum one (that’s clean as a whistle) and there was no change in the error code. Plus, I then tested it with my multi-meter, here are the results:
1) With the harness disconnected and the engine/ignition off:
All three wires (red, black and yellow) ohm-ed out as ground.
2) With the key in the ignition and it turned to run position without the engine on:
The power wire (red) had almost 13 volts, the ground (black) wire was grounded, and the signal wire had about 6 volts.
3) With the engine running and the harness attached:
I tested the Hertz with my TEST BENCH set to 20 Hertz and the signal wire (yellow) had a fairly consistent 2.14 hertz at idle (engine warm) and when the engine revved it smoothly went to just above 14 hertz and then evenly went back down to 2.14 when the idle was slowly released.

I ran the car with my Foxwell attached and the Foxwell has a (g/s) reading for the MAF during the events in real time. It seems it was registering 4-5 during idle and was at the 40-50 range when it was bogging down, but when it cleared and accelerated as expected, it was well into the high 60s and into the 70s.

With GM Tech 2
Finished (though I had to go to a shop with a Tech 2 and basically rent it with the mechanic).

Everything is factory spec, and it idles and revs without issue. No trouble codes. Everything is within spec. when we looked over all the info in his Tech 2 readings.

When driving (though markedly better and gets up to highway speed great), still it seems the engine, as it is accelerating: feels that it either adjusts the fuel/spark a bit, or the transmission shifts prematurely into a higher gear or something (that’s the only way I can describe it). It’s weird to feel the car do something without driver input. Whatever it is is keeps the car from continuing its acceleration for a few seconds. If I give it throttle during the event, it downshifts and accelerates great through the issue. If I don’t alter the accelerator, and keep it steady during the event, it waits a few seconds and then shifts to overdrive and feels normal.

Since I changed the fluid and filter when I first was alerted of the issue by my daughter during my maintenance work, and the old fluid was discolored (aged) and there was no metal dust or filings on the magnet, I’m wondering if I just need to allow her to drive it and change the fluid again in a few days and see if it flushes more of the old fluid that was trapped inside the torque converter?

PROBLEM SOLVED
So my friend has some awesome equipment to test Hz and other sensor feedback and we looked at the Knock Sensor and the O2 Sensors (much more sensitive than mine as well as had the exact ranges of signal that should be expected). The Knock Sensor and the O2 Sensors both looked slightly out of spec, enough to do a test drive with first the Knock Sensor disconnected and then a drive with both the Knock Sensor as well as the upstream O2 Sensor disconnected.

With the Knock Sensor disconnected the drag or delay in acceleration under load was gone, though it wasn’t completely smooth. With both disconnected, it drove really well and there was no drag or delay or alteration of power during driving. I replaced both the Knock Sensor as well as the upstream O2 Sensor and tested the car again. It drives as it should.

So, in the end, the car had these issues:
1) the #1 cylinder had a head gasket leak, fixed with head gaskets replaced
2) the MAF sensor was sending inaccurate info and had a damaged wire, replaced
3) the vacuum Transmission Modulator was broken, replaced
4) the upstream O2 Sensor was not within spec, replaced
5) the Knock Sensor was sending wildly inaccurate info, replaced

Interestingly, only item #2 above was determined by the PCM to be in error and would throw a Service Engine Soon light or throw a code, the PCM was silent on the other errors. I guess a ’97 GM PCM was not very sophisticated.

Hope it helps!

2002 GMC Sierra Scan Tool or Diagnostic Tool you use – pros and cons

Car model and year: 2002 GMC Sierra 1500

Purpose: to pull codes

Scan Tool or Diagnostic Tool to use – pros and cons

1. GM Tech2 pros and cons
To do work on gm stuff I have knock off Tech2. I like it.

2. My OBD Link MX+ or Konnwei Bluetooth devices with the usual Dash Command, Torque Pro, OBD Link and Motor Data apps work for me for troubleshooting.

For us LS engine swap people that don’t like to pay the HP Tuners folks money to license a new operating system, there are now free alternatives. “Tuner Pro RT” software allows the free editing of a General Motors PCM operating system to get it to work in a swapped vehicle. Then we use “LS Droid” software with my MX+ device to actually write the changed Tuner Pro operating system to the PCM which completely avoids spending money on HP Tuners.

3.
For a long time I have gotten by with a simple scanner. These days with the Bluetooth devices and the torque app…that is even easier for basic stuff. Back in 2011 I picked up an Innova 3150 which had the ability to read ABS and SRS system faults. It was about $150 then. Current ad for this older tool shows $220…not sure why xxxx
I have considered a clone Tech2 and or the MDI device I have seen mentioned. My main concern other than the $300 cost…which is not bad for what it does….was that I did not want to somehow brick my ECU or any other module either due to the clone tool or my lack of knowledge of using one of these more sophisticated diagnostic tools.

I decided to get one that would perform the ABS bleed, mainly because I like to flush the brake fluid ever few years. What I ran across for the least $$ to fit what I was looking for is the Foxwell NT630 Plus. Listing made an offer to another listing but they would not budge. (why do they show make an offer if they only will drop a dollar?!). The one Currently my plan is to sell the Innova locally and try and recoup most of the cost of the new tool.

4. My 2001 GMC truck has a problem with the red brake warning light and the yellow ABS lights randomly coming on at the same time. I wanted to find out what code was being set. I quickly learned the local auto parts stores couldn’t read ABS codes. I also learned that the repair shops in my area charged $35-$59 just to use their scanner to check for ABS codes. I thought that was too much for a 5 minute scan so I decided to buy a scan tool that would read ABS and SRS codes as well as OBDII codes. Over the course of several weeks I have purchased three scan tools and returned each one of them for a refund for reasons I will describe below What I wanted a scan tool to do.

I initially set out to find a scan tool that would read ABS, SRS and OBDII codes on all my vehicles, a 1999 S10 Blazer, a 2001 GMC Sierra, a 2012 Equinox and my daughters. 2009 Camry. I wanted to spend no more than $125. I know that sounds like a lot to hope for but I figured I might be able to do it.

Then I confirmed Tech2 is able to do ABS Brake Automated Bleed & Pressure Bleed for Chevy & GMC. Just google ” GMC Sierra 2002 Tech2″ and you will see a Youtube video on how to do.

5.
Question: Will this gm tech2 work with my 2012 GMC Sierra 1500. Will I be able to calibrate the BPP sensor out of the box? Thanks!

Reply:
If you scroll down further it lists it as going to 2013. I bought one like this and it has been great to diag and repair everything. Too bad it doesn’t work on my camaro(MDI).
Could be, but there was an updated 32MB card that supported up to ’13.

Or get a Jbox or an MDI2 as it can do anything a tech 2 can and much more. I can go into much more detail if needed but don’t buy a tech 2 it’s outdated and obsolete as of 2013 at best. I have 4 scan tools ranging from 300-5000$ and you can easily spend 500 or less and do anything I can.

It’s called the open port 2.0. It is compatible with GM’s programming website called SPS. That tells me it’s a go for the tech 2 win program which is a laptop version of the handheld tech 2. It also would work with GDS2 which is the current diag tool via laptop for GM. Then you can lease the use of the software as needed.
https://www.acdelcotds.com/acdelco/action/subscribehome This is The site to lease the programs. It may not make since for some people but if you are devoted to “doing it yourself” it’s the only way, end of story. You will use other software to diag the problem and then slide over to gm’s stuff if needed but this will give you the widest range of functionality.

GM Tech2 Clone PCM Reprogramming on 96 LT4 Corvette Works

Big thanks to @ grandspt for his experience sharing.

I purchased a 1996 PCM that was used for short money, my goal was to keep it as a spare for my ’96 LT4 Vette since parts are getting harder to come by.
I removed my PCM and installed this used PCM. I took out my GM Tech 2 Clone, opened my Windows XP Netbook that I had previously installed the TIS 2000 software (this software disk came with the Tech 2 Clone). I opened the TIS 2000 application and went to the “Service Program Application” and followed the steps to “Reprogram ECU”.
Now this used PCM obviously had a different VIN. So during the program when it prompted me to see if the VIN was correct I deleted the old VIN and entered in my cars VIN.
Then I uploaded the program for my VIN into the TECH2 Clone per the prompts, disconnected the Tech 2 Clone from my Netbook and connected my Tech 2 Clone to my OBDII port. I turned the ignition ON without starting the car and selected “Service Programming System” followed the prompts and watched the TECH 2 Clone load my VIN programming for my car.
It worked great, in fact I bought a second 1996 PCM for $150.00 and performed the same procedure and that one worked just as well!
After I used my JET DST to upload my Tune for my engine into the PCMs. The Tech II will obviously only install the factory calibrations. Now I have two spares in case my original fails.
Hope this information is helpful.

TIS2000 Application

Here is where you select Reprogram ECU.

These are the prompts for the Tech 2 setup.

First I only have a 1996 with the OBD II, this is all I could experiment with so I can’t check other years.
I think it can also work on the 94, 95 model years as well, but I could be wrong.
The TIS 2000 software comes with the Tech 2 scanner.

GM Tech2 Diagnostic Scanner Descriptions

If you are looking for a car diagnostic tool, you could think of Tech 2 Scanner. This post will offer more information about it.

Tech2 scan tool Features

1) Authentic GM software in the Tech 2 Flash means the most comprehensive diagnostic software available for late model GM vehicles.
2) Support for on-board diagnostics on all GM systems 1992 thru 2011.
3) Removable hardware modules provide insurance against scan tool obsolescence.
4) Large, easy-to-read backlit screen.
5) RS232 & RS485 ports provide the avenue to connect future devices to your OBD2 Scanner Tech 2 Flash.
6) Ability to capture stored DTCs, Freeze Frame, and Failure Record for later review.
7) Ability to view the status of vehicle diagnostic tests as they run.
8) Bi-directional The authentic GM 1992-current year software will provide full bi-directional control when performing power train, chassis, and body diagnostics.

Tech2 Specification:

1) Dimensions: 12
2) Microprocessor: 32 bit,16 MHz
3) Memory: 32 MB flash type II PCMCIA. Type III slot available for future expansion.
4) Communications: Integral RS232 communication port.
5) Screen: 3.8.8 backlit monochrome with full graphics capability: 320,40 pixels. Displays up to 9 vehicle parameters at once. Download Tech2 Brochure (5.2 Mb)

GM Tech2 Package List:

Tech-2 Flash Tester
32 MB PCMCIA Card with GM OE Applications
CAN diagnostic interface module(Candi) and instruction sheet download (199.2 kb)
RS232 cable and user manual
RS232-DB9 adapter
DLC Cable, DLC Loopback Adapter
12V Cigarette Lighter Power Cable
SAE 16/19 Adapter
NAO 12/19 Adapter
Battery Power Cable
Storage Case
TIS 2000 CD

How to use the GM Tech2 scan tool to perform GM SPS

Topic: GM SPS Programming: Tech2 Tool Pass Thru Mode ECU TIS2Web TDS Calibration Update
How to use the Tech 2 Scan Tool to perform GM SPS Programming in what is known as Pass-Thru or Legacy Pass Thru mode for calibration updates. This can be for the ECU or any programmable module in the vehicle, such as the EBCM, TCM, or Radio that you may want to reflash.

I’m going to show you a little bit newer technology. So we’re still with the tech two and at this point I’ve pre-connected some things up here I’ve got connected to the diagnostic interface this the unit accessory for the tech two called a candy module a controller area network diagnostic interface. So this connects to the vehicle and then it connects to the tech 2 and then in the tech 2.

If we were to go into our SPS system what I’m gonna try to show you here. This particular vehicle work we’re working on right now is a 2009 Chevrolet Cobalt.

If we go to request. What we’re gonna find out really quick is after we say Chevrolet well. We don’t have anything newer than 2007 that we can select. Because this 2000 which is what the remote mode is set up for.

So how can we update the firmware on the modules for this 2009 well we’re gonna have to go to this to web on the internet. So I’ve got this cable already connected to a laptop over here and we’re going to go ahead and show you how to stew web works which replaced this 2000. So I’m gonna set this guy right next to this laptop sitting on the passenger seat here.

Warning: Pay very close attention to the instructions around power cabling and battery readiness as a power fluctuation during an SPS programming procedure can permanently damage a controller module.

This applies to the genuine Vetronix, HP or Bosch built Tech2 as well as high quality Chinese clones equally and for all makes under General Motors such as Chevrolet, Buick, GMC, Cadillac, Oldsmobile, Pontiac, Hummer, Saturn, Opel, Vauxhall, and Saab.. The programming is illustrated using a 2009 Chevrolet Cobalt LS and the www.acdelcotds.com subscription service features using a Techline PC using Tech2 legacy passthru mode to update the Radio.

Applicable to model year 2008 thru 2013, which is when the Tech2 ended and was fully replaced by the GM Multiple Diagnostic Interface tool, or GM MDI and MDI 2 and TIS 2 Web subscriptions. This method is available with TIS2000 for GM vehicles older than 2008 as well.

I recommend that you buy gm tech2 on Obd2 tool website. They are cheap, logistics is fast, and after-sales service is also very good. I have been using it for a year and there is no problem with the quality of the product.