I have an 88 GTA, 305 TPI. I bought this car non-running, and have been tinkering with it for about a year.

The engine idled unevenly at times, OK at others, and was hard to start once I started driving it every day. She also had a tendency to buck at low speeds, but over 10 mph the car ran well. After reading a lot of different threads, I decided to replace the original injectors with Bosch III's.

The hard starting problem seemed to be solved, but the car still ran unevenly at idle and bucked at low speeds. When I pulled the MAF sensor connector, the engine smoothed right out. So, I ordered one, and installed it. That did not solve it.

Next, I pulled codes, and got 44, lean 02 sensor. Since I had no idea how long that had been in place, I replaced it. No help.

I finally ordered an ALDL cable and downloaded TunerPro software. It took me a while to figure out how to get it to work, but once I did, I cleared the codes, ran the engine for several minutes, and read the data.

These are the notable readings that I got, with the car running, in real time:

• coolant temp: -39.99*C
• Startup coolant temp: 227.93*C
• BLM 158
• INT 160
• Code 33 MAF high
• Code 44 02 sensor low

So I replaced the coolant temp sensor, which I believed had utterly failed.

Again, no help.
Once again, I hooked up the laptop. The readings were the same as before.

Could I have a bad ECM? Am I doing something wrong with TunerPro? I have lots of mechanical and electrical/electronics experience, but almost none with TPI.

I would be grateful for any help anyone could provide.

 

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Replace the MAF sensor. Been there ,done that....twice.
Make sure you have the proper input voltage to the sensor from the ECU.. FIRST.
I believe it's 5 VDC.

 

Napa has computers for a good price. However, my car was running lean also and it turned out that I needed a fuel pump. No probs since. Check the fuel pressure to narrow that out before replacing the computer. I also added a heated O2 sensor which fixed the car to where I could drive as soon as I started it instead of warming it up first. I have headers so my O2 sensor wasn't reaching the correct operating temperature right away. My car runs like a champ now.

 

If it is to be your ECM , I have one out of a 87 305 TPI I can sell you, I also have the MAF sensor for it.

 

OK... the MAF sensor is brand new. That was the first thing I replaced. I have also changed the 02 sensor.

When I first got the car, I had to replace the fuel pump. When I changed the injectors, I verified that my fuel pressure was up to specs.

My question is about the CTS readings. Unless I am doing something wrong with TunerPro, it seems that the CTS is not reading correctly. So I changed it. Now the new one is giving me the same readings, and that is why I thought the ECM might be bad.