OK guys. I had to use an old POS laptop to datalog. It worked great, but currently I have NO WAY of getting the log off of the stupid thing. So here is what I noticed that I "think" is out of the ordinary. I have never datalogged before, so I have no idea what numbers are good and what numbers are bad, but using common sense I determined the fol,lowing things should not have happened:


I am one of the lucky few that has to jumper the ALDL port with a 10k Ohm resistor to get the ECM to send data so my idle during logging was high at around 1000RPM. But during idle I noticed that the car would shake and breaks could be heard in the exhaust note like a misfire. This only occured at this RPM. Other abnormalities can be felt at other RPM's but only at around this speed was it this badly pronounced.

I also noticed that the O2 sensor reading was fluctuating between .200 and .600. Is this normal? Common sense would lead me to believe maybe a misfire is richening the exhaust and whenever the cylinder opens for exhaust it throws the O2 way off? I also noticed on the WinALDL Flag Data screen the "Rich Flag" was cycling on and off. Also, "DRP Occured" was cycling on and off. What does this mean?

Also, I read somewhere that BLM's (Forgive the noob question but what are BLM's?) are supposed to be as close to 128 as possible. Mine were reading 150+.



What does all of this information tell you guys? I know that the datalog would really help. I'm working on it. Thanks guys!

 

the O2 reading should bounce around, so what your seeing is mostly normal. the part that isn't normal is the .600, it really should go higher, .700 or above.
but, with a BLM of 150, a lower than normal O2 reading is somewhat expected.

im not familiar with WinALDL, so im guessing that "DRP Occured" means there are distributor reference pluses which is good, the motor won't start & run without distributor reference pluses.

the Rich Flag cycling on and off is the O2 sensor cycling from high to low voltage, perfectly normal.

now, what you've said tells me your running lean.
some things that it could be caused by are bad gas, an exhaust leak in front of or just behind the O2 sensor, a weak or bad O2 sensor, vacuum leaks, air leaks between the MAF sensor and throttle body, a bad MAF, low fuel pressure, injector problems, wiring problems.

what if any codes does it have?

 

It has 3 codes stored.

Code 24 it throws randomly. But I think this is unrelated to my issue. Code 44 it throws every once in a blue moon. Here is the strange part: It used to throw code 44 at least once every day or so until my alternator died. When I replaced the alternator, I unknowingly knocked a fitting off of the AIR diverter valve tube, creating an exhaust leak. For the next 4 days I went mad trying to figure out why I could not drive more than 5 minutes without a code 44. It got so bad at one time I was brake torqueing the engine to check for anything out of the ordinary and I stabbed it right as it was revving down. The engine choked and backfired through the intake. Once I found the leak and tightened all the clamps (Some were a bit loose), it threw it once while relearning the ECM, and maybe 1 - 2 times after that. It's been about 2 weeks since the fix.

Code 34 it has thrown twice in the entire time I've owned the car (Almost 2 years now).

- Bad gas is def not the culprit. This is my daily driver.
- Exhaust leak is quite possible. Not ruling that out. What is a good easy way to check?
- Bad o2 sensor I kinda doubt since I just replaced it last year, but it wouldn't hurt to try a new one again.
- Low fuel pressure. Hmmmm. Not sure about this one. I would consider it since the car has trouble cold starting (Does not want to fire unless you manipulate the throttle) and random misfires. But if it was a fuel pressure problem wouldn't it make sense for it to get worse as RPM's increase? The engine feels like it only performs bad down low. It looks like It's been awhile since the fuel filter was replaced, but I can't get to that right now since the fuel lines are badly rotted and I'm saving the money for new ones. It misses the worse in the 700 - 1000 range. The whole car shakes and breaks can be heard in the exhaust note. it doesn't sound like a consistent misfire IE not in a steady rythm like it would be coming from the same cylinder.
- MAF could quite possibly be bad due to the codes. What is a good way to test my current one?
- How would you recommend to test the injectors and the wiring? I ohm tested all the injectors and they checked in at 17.5. But obviously that doesn't say anything for flow and wiring.