Good evening,
I've been pretty busy for the last year, and focusing on cleaning up other parts of the car. Suspension, brakes, recapping the radio, etc., but the engine is always on my mind. It still doesn't "feel" right. On Saturday Morning, I took the car for about 20 minutes of driving at different speeds, RPMs etc, while data logging. I found a couple of things.
1. About 15 minutes into the drive, the TPS went from running the full range to over 100%. I've had it throw the code before, but when I've checked it with the scanner and the handheld meter, it has always been within spec and moved smoothly through the range. I've never seen it happen until now. Is it a bad sensor, or is there someplace else to look - like a ground or something?
2. The entire time, the BLM oscillated between 0 and 255 about every 30 seconds.... the INT bounced back and forth, but I didn't see any pattern to it. Is that normal?

Thank you for any suggestions!

 

No, it is not normal for the INT to jump around much if it has been a while since you reset your computer or made any other changes. If it was still re-learning, maybe.. but if the CTS and IAC are pretty steady you shouldn't be jumping all over. This probably means the 02 is providing some odd data.

Just going to give a wild guess that it may be a voltage/grounding issue. At least, I would be investigating that. Do you have any long flat roads you can maintain a constant speed and throttle on? You could get the car warm and try to keep everything as constant as possible and see if sensor readings are jumping around. If so, it's probably not multiple sensors failing.

On the other hand, the O2 could be going bad. However, the TPS jumping suddenly could put the ECM into power enrichment mode. Suddenly switching the information the ECM is using for target A/F ratio. It's a tough one, going to have too watch everything closely. I would compare behavior to the CTS and TPS and see if there is any correlation to the time when the BLMs and INTs are jumping around.

 

When I checked the TPS this evening, it was reading very high. I removed it, shook it to get get rid of any gunk in the connector, and ran the full range a couple of times. I put it back in, adjusted it, and it seemed to be reading correctly. I'll need to order another one soon.

I took the car out tonight, and drove it on the freeway at about 2000 RPMs for 5 minutes, got off of the freeway and got on going the other direction and cruised back at about 2000 rpms, and then got off and went home. I've attached the data logging file. I did notice some sort of electrical or other issue where there was really bad data twice for a single reading (filter for RPMs < 100) Here's what I observed:

1. The MAF and TPS seem to be in sync - which is what I would expect.
2. The SENSOR:BLM has that saw tooth curve, but the RAW:BLM does not. i don't know what that means.
3. The INT bounces around a bit
4. The O2 sensor is all over the place.

Am I reading the data right? Does it speak to any of you wizards?

 

The text files are hard to sort out.
1. Good, but you previously stated they weren't. This could have been messing with where the computer "thought" it should have been operating and it is now doing some re-learning.
2. I am not sure on this one, I don't think I ever saw a difference on mine switching between sensor and raw data on the BLMs. Someone else will need to chime in on this one because I don't remember it being different and I am not sure it wasn't.
3. Since the file is hard to sort out. Do you mean the INT is moving as your driving conditions change, or what range are you seeing?
4. 02 sensor should bounce back and forth and provide cross counts. that is perfectly normal. If it is not, it is likely bad.