I connected the scantool to the engine today and took screenshots at different stages. Except for the fact that my VSS sensor shows no reading and I know why, I have no idea what all this means. Please help and enlighten me...

Engine off, ignition on:

10 secs after engine start:

1 min after engine start:

The moment the engine went into closed loop:

Engine warming up, driving slowly:

Operating temp reached, driving in 2nd gear:

Is it normal that the engine switches between lean and rich mixture all the time?

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[This message has been edited by yellowstone (edited 04-01-2006).]

Anyone?

Yes its normal for it to switch back & forth ==02 sensor... Your blm & int are hair high--but with-in acceptable range.. 128-135 Your best readings are going to be fully warm engine while driving 55mph for 15-20 minutes.....

Is there someone who can explain the individual readings, what they mean and what an acceptable range is for each?

Hi, Its a long techie one--take your time reading it---it will explain most anything you need to know about this--if you have any problems --just post it again on that post or ask away...

As you play with your software you will figure out more. don't know what program your using but does it have a graphing mode?

For it's shortcomings, The one thing I like about Winaldl and Aldlview is being able to graph the readings and overlay them on the same graph so that you can see how reading compare and affect each other.

Like 3800SuperFast posted, read the other post and you should be able to start to make since of what it going on.

The Aldlview is that a part of the WinALDL software or a seperate program?

edit: never mind I found it on the other thread.

[This message has been edited by Fiero1Fan (edited 04-02-2006).]

quote Originally posted by Fiero1Fan: The Aldlview is that a part of the WinALDL software or a seperate program? edit: never mind I found it on the other thread.

The big articale in the post is what you want to understand first, then the actuall reading /graphing stuff comes in real handy when you know what all of it means, dodgerunner is real good at the graphs and weeding out the driving logs that you will be doing---he taught me !!!

WOAH !!!

Where would I lay my hands on that piece of software and the appropriate cable?

quote Originally posted by under8ted: WOAH !!! Where would I lay my hands on that piece of software and the appropriate cable?

Drop srat110 a pm. He has the software (freeware) and sells the cable.

Heres your free ware http://winaldl.joby.se/

The Fiero Store sells it: http://www.secureleadercom.com/fsstore/default.asp?searchBit=1&searchType=t&searchString=scan&howSearch=AND&searchfield=inetsdesc

quote Originally posted by under8ted: WOAH !!! Where would I lay my hands on that piece of software and the appropriate cable?

My thoughts, for what they're worth.

The data output rate from the stock ECM is slow, real slow, only 160 baud. That means that a complete frame (set of data from various sensors, BLM/INT, etc) takes about a second and a half to put out. The ECM operates much faster than this internally and almost all of the sensor values change much faster than this internally. Basically, what you get with this ECM are snapshots of the state once every 1.6 seconds, so fast-changing data like the O2 sensor's output is meaningless to look at via the ALDL interface. However, what you can do is see if sensor values that normally change are pegged to one end of the scale or the other. So, if you hook up WinALDL and see that the O2 sensor voltage never fluctuates, staying at .8V all the time, you know you have a problem for instance. You can check the MAP sensor by applying vacuum to it with a hand-held vacuum pump while looking at the ALDL out put to see if it reacts properly to the amount of vacuum applied. The TPS you can check by looking at the voltage with the pedal floored (engine off of course!) and with the pedal all the way up, but the frame rate is so slow that you probably won't be able to see spikes and transients in the TPS output via the ALDL.

What I find most valuable is logging the BLM and INT outputs on long, varied drives. This logged data when put into a spread sheet can graphically show lean and rich problems, particularly helpful when tuning. Persistant high and low BLM/INTs can also indicate other problems on stock engines.

The process of dealing with the ALDL data stream begins with converting the varying 12/0V signal at the ALDL connector to something that can be read by a PC, then the next step is to convert the raw data into values that can be understood, such as voltage, degrees, etc. The basic WinALDL cable that can be easily homebuilt converts the voltages into a signal that can be read by a PC's serial port, and the sofware WinALDL converts the raw data into useable information. The unit that the Fiero Store sells has a microprocessor built into it so that both the signal conversion and data conversion occur inside the unit, and it has a USB output that easily works with the more modern laptops and OSs. BTW, the Fiero Store unit was designed and built by Oliver Scholz, he sells the preprogrammed PIC if you want to buy it from him directly.

WinALDL has the ability to do logging, which the Fiero Store unit does not, though it's possible that someone can write logging software to work with the FS unit.

Anyway, lunch is running short, gotta go...

JazzMan