First log, what does it mean, and how to fix it.

[95Gstman]

I was wondering if someone could take a look at this log, and tell me what it means. I had a suggestion that it could be a bad o2 sensors making the comp run lean. I was just wondering if anyone else had any input. Sometimes my car will studder at high rpms, and I don't think it is pulling as hard as it should be with the mods that I have. (see profile) Thanks for any help/suggestions.

 

[Gstclipse69]

Do you have anything to tune with? I see you have an upgraded turbo and fuel pump but do you have larger injectors or are you still running 450s? Your o2s look good up until about 5k rpms after that, from the log it looks lean, real lean. If the o2 sensor was bad it seems like it wouldnt be registering the .96 only until 5k, so it seems that the o2 sensor is good.

 

[95Gstman]

Don't have anything to tune with as of yet, will be gitting something soon. I am also on the stock injectors. Also, the only reason I upgraded the turbo before some of the supporting mods was because I got a really good deal on it and had the money, so I could not pass it up.

 

[Gstclipse69]

How much boost are you running? Whatever it is I'd turn it down until you get the supporting mods. Running lean is not good. The turbo is flowing more air than your injectors can compensate for. Either grab you a safc from the classifieds or depending on what your goals are go ahead and get dsmlink, although its more pricey but also more user friendly.

 

[95Gstman]

I am running 14psi, I figured that the 190 would be enough fuel to support that amount of boost without injectors? Also, I thought that running lean would make my car feel faster not slower? I mean, I am not trying to run that lean (I want to be safe) But just a general rule isn't leaner=faster?

 

[Gstclipse69]

You want your car to run on an approximate air/fuel ratio of 11:1. In an o2 sensor bank this is ~.96, .94. If your running lean in open loop (wot) then your going to knock. If you have a high knock count then thats going to destroy your motor. The stock afr that the ecu goes on is 9.5:1, which is too rich but thats on a stock turbo. I havent heard of leaner=faster. Basically thats saying your just throwing more air in your a/f ratio. Flowing more air=hp but flowing more air without adequate fuel = knock.

I may be wrong about the injectors, but Im going by what the log is saying. Might wanna check the fuel filter.

 

[95Gstman]

Is re-wireing the fuel pump hard/expensive, maybe I will also try that.

 

[turbosax2]

Hard? No. Expensive? No.

2G DSM FWD Fuel Pump Rewire Instructions

 

[95Gstman]

Do you think doing that will help solve my problem? I know it will net some gains, but do you think that inadiquate fuel is my promblem, or is it problably something else?

 

[linksys42]

How does your o2 bank 1 look when just cruising around or at idle does it oscillate jump back and forth from .20 to .80? Because if you were really running that lean you would be knocking and the timing should be getting pulled. But your timing keeps rising till 6500 rpms. I would still be really careful till you figure out the problem. Turn down the boost to 10psi then go do a pull and see if your o2's stay in the 90's all the way till 6500.

 

[Rob10_99]

First hint was it takes you 14 seconds to rev out a single gear, to 6500 no less!
What gear is that pull in?

 

[mattdev]

What about the knock sensor? Would a faulty sensor cause it to ignore knock and continue to advance even in lean conditions? This is just a logical post, I don't know how the knock sensor responds if it is broken. If the computer sees knock it pulls timing, and judging by your a/f, you are definitely in knock territory. Should be pulling timing, but isn't, based on your a/f.

However I don't think you can rule out a faulty o2 either. It could be just the opposite. It could read normally up until it sees a good deal of action/stress (wot past 5k) and then start throwing inaccurate readings.

Seems to me one of the two could be faulty, however, I'm no wiseman. And thats an understatement.

And yes, btw I was at midnight madness...

 

[95Gstman]

How does your o2 bank 1 look when just cruising around or at idle does it oscillate jump back and forth from .20 to .80? Because if you were really running that lean you would be knocking and the timing should be getting pulled. But your timing keeps rising till 6500 rpms. I would still be really careful till you figure out the problem. Turn down the boost to 10psi then go do a pull and see if your o2’s stay in the 90’s all the way till 6500.

Well, to do that log, I borrowed a logger, as I do not have access to one of my own yet, so I do not know how soon I would be able to get another log up. Unless someone in the San Marcos area has one that I could do another pull on, it may be awhile before I can run another log.

First hint was it takes you 14 seconds to rev out a single gear, to 6500 no less!
What gear is that pull in?

That was a 3rd gear pull.

 

[linksys42]

Well, to do that log, I borrowed a logger, as I do not have access to one of my own yet, so I do not know how soon I would be able to get another log up. Unless someone in the San Marcos area has one that I could do another pull on, it may be awhile before I can run another

I would still turn the boost down and stay out of it. Just to be on the safe side till you buy or borrow a logger and figure what is going on. Because that o2 droping to .20 by 6500 would really worry me even if the timing isnt showing any kind of knock. But still this is the narrowband o2 sensor which are not good to tune by in the first place, but it still gives you an idea. Do you know what datalogger you were using to take this log?

 

[95Gstman]

Yeah, it was on a pocket logger.

 

[95Gstman]

Well, I should be ordering my pocketlogger in a few days, so hopefully I will be able to get some more logs up of what you guys are asking. Would running that lean cause my car to pull so slow? I am just wondering if the two problems are connected, or if they are two seperate problems, thanks for all the help.