My car has been running rich since i first started it. I hooked my laptop up to it and i noticed the Right BLM's are in the 160-170 range and the target is set at 128 i believe. I switched the O2's and there was no change. I am going to change my spark plugs again but i dont think there is anything wrong with them. What could cause this? There is NO exhaust leak as far as i am aware of (which i am 99% sure of). If any other info is needed then just let me know. Any help is appreciated.

Brandon

 

The BLMs max out at 160, how the heck are they in the 160-170 range?

 

Sorry im just trying to remember from yesterday. I know for a fact that it said 160 though. Either way it is running way higher than supposed to. What can cause this?

Brandon

 

BTW, which bank is the Right bank? I took all of the plugs out of the drivers side and they were all pretty black. The #3 Cylinder plug looked a little wet too. What does all this mean?

Brandon

 

Bank 1 = drivers side = left side = cyls #1/3/5/7
Bank 2 = passenger side = right side = cyls #2/4/6/8

You have a "false lean". Something is telling the sensor the exhaust is lean, and the PCM is adding fuel you don't need.

What cells are the right side BLM's at 160? At the same time, what do the left side BLM's look like? That will tell you under what conditions the "false" reading is worse, and whether its a problem that is affecting both sides.

What do the

 

I agree.

Two things you need to find out:
1) Is the system in closed-loop?
2) What is the O2 reading of that side in closed-loop when it has a BLM of 160?

Tom Piper

 

I changed all the plugs and was able to get a few datamaster logs in for you guys to look at if interested. It seems as both sides are giving the false lean condition. The left bank is running at 142 and the right side at 160. When in closed loop, the left bank moves to the target setting, 128 and the right bank seems to move to the 130-140 range. At WOT they are both at the target setting. I kept loosing connection to my comm port for some reason so the graph may look a little strange.

The right O2 seems to be strange. It varies from the teens to 900's while the left O2 stays in the 700-800 range throughout most of the cycle. If either one of you want to host this for me i can send it to your email. Any help would be great as i am scratching my head with all of this.

Brandon

 

For the most part, this sounds normal -- the 130 is nothing to get excited about, the 140 is ???
From the readings, I would not expect a rich mixture in closed-loop.
Do you think the mixture is rich at this point?

I'm assuming that 128 is what you are seeing, that seems normal for WOT.
There is no O2 feedback in use in WOT.

If you are talking closed-loop at this point, the O2 sensor should vary from a low reading and cross the .450 to the high side and back, so it sounds like the right side is doing its job. A lazy sensor will see less cycles in the same period of time.
The one that is staying at 700-800 most of the time, assuming it isn't defective, is telling you the mixture is rich.
If you are talking WOT or open-loop at this time, all bets are off.

But, my gut-feeling is you have an exhaust leak sucking in oxygen or a defective ECM calibration.

Tom Piper

 

Tom,

Would you like to look at my datamaster logs? I am really trying to get someone to look over them and see whats going on with the car. Let me know if you can and i will send them to you.

Brandon

 

Look for a rip in the intake elbow and maybe try carefully cleaning your MAF sensor.

 

Brad,

Did you get a chance to look over the datamaster log i sent you or did you just see this thread and replied to it? Just wondering if this comment was from looking at the data or just from previous experience. Thanks

Brandon

 

Why is your target idle RPM set at 1000? I dont see a cam listed in your sig so I was kinda wondering about that because it would change a couple of things that might possibly be a problem on a stock motor.

First off it appears you need to order a new O2 sensor for the pass side. If you look it is stuck at .004mV in closed loop... its essentially dead. However, in the event the sensor is good and you are just running extremely lean, you should swap it to the other side and see if the same problem follows that sensor.

2nd the Sterms are not moving in closed loop... if they dont move, they cant control fueling which may be why the motor is running so lean.

3rd the IAC is maxed out in open loop which would be unusual on a stock motor. As well as the MAF readings are considerably high which again is unusual on a stock motor... althought it might be explained by the high target idle rpm.

I hope that helps you a little. Again, the main issue im seeing is lean.. not rich.

 

Sorry i havent really updated my sig. My setup is not so much stock. Program is from pcmforless.com:

Built 355, compression around stock range
CMS Stage II heads and custom grind cam (236/242 .608/.576 111)
1.6 Pro Mags
stock ignition
descreened MAF
AS&M Monoblade
K&N FIPK with 1350 cfm filter
Pretty Much all boltons Possible

I think i may have a problem with my wiring on the pass side O2. When i pulled the engine from the bottom and was putting it back in, i routed the wiring harness that has all the wires for the pass O2, starter, KS, and a few more behind the tranny and the harness would not reach to the PCM where it needed to go. Instead of pulling the entire engine out again to get to the re-routed harness i made the mistake of cutting some of the wires and splicing in an extension.

I am not sure if this could be causing the problem or not but i think i made a mistake by cutting them and dont know how to go back and fix it. I am not sure if any of the wires need a certain resistance for the PCM to read the sensors correctly. I dont see why this would cause the drivers side to be sensing the false lean as well and the BLM reading at 142?

I dont know, what do you think?

Brandon

 

I dont think you have a false lean. Judging by the O2 output Id say the motor is running lean. You need to get some logs driving around at a WOT run to see if the Sterms move any b/c on those 2 logs you sent me they werent moving. Its my understanding the Sterms control fueling.. not the Lterms.

 

The car is definitely running rich. When i start the car and let it idle for a minute or two inside of my shop with the bay door open, the fumes smell like fuel so bad you can hardly breathe. The smell gets all over your clothes even when your outsied with the car and standing close by. So i know that it is running rich when at idle. Other than that it may be running fine, im not sure.

I can try to get some WOT logs when driving the car but i will have to see if any of my buddies have a lap top i can use because i have to take my desktop out everytime i want to run datamaster

Injuneer is going to take a look at the data i sent him and get back to me in the next day or two so i will see what he has to say. Thanks again.

Brandon