snowzach

Heh, sorry for the long post.. want to clear some things up...

So, I decided that I wanted to do some data logging with my computer on my semi-stock 85. I did plenty of searching and had a lot of trouble getting started. I thought I would post this thread to both serve as help for others searching to get started as well as verify my results.

First off, I built my interface myself. I'm a bit of an electronics hobbiest and I had all of the parts I needed to put it together.

I built a cable using the schematics from the WinALDL site here: http://winaldl.joby.se/

After building the cable and it seemed to work well with WinALDL which is a free package. I also tried it with a couple others including TunerPro RT http://tunerpro.markmansur.com/ which seems to be popular here.

This is all for an 85, things may be different for other cars. I'm sure someone can chime in.

If you hook it up as is, the ECM will only send you 5 values which doesn't populate WinALDL completely. You need to install a 10K resistor between pins A and B on the ALDL connector. On my ECM it then sends 25 values per pass. Make sure you have the right ECM selected or it may show the wrong data for the wrong variables.

Anyways, and please correct me if I'm wrong, I wanted to look at the rich/lean adjustments of the motor.

You can do this in two places...
1. Check the INT value. This is the short term adjustment of the ECM. If it's running right it should hover near 128.
2. After driving for a bit, the BLM (Block Learn Mode) table will populate (in WinALDL anyhow) These are the values that the computer has adjusted the stored program to maintain a correct O2 readings such that it's burning most efficiently. Optimally, I think these values should be around 128 as well if the motor is operating correctly right?

You can also check lots of other values in there, but these were the ones I did the most reading on this. So far, are these assumptions correct?

Based on that, I have my BLM table from WinALDL

RPM \ MAF 24 48 72 96 120 144 168 192 216
400 0 0 0 0 0 0 0 0 0
800 117.9 120 0 0 0 0 0 0 0
1200 117.7 118.7 0 0 0 0 0 0 0
1600 113.1 116 116 0 0 0 0 0 0
2000 111.8 118.7 116.7 125.3 122 0 0 0 0
2400 113.3 118.7 118.9 121 128 0 0 128 0
2800 114.5 116 122 117 0 128 0 0 0
3200 113.8 115.2 118 117.3 0 0 0 0 0
3600 114.9 118 0 0 0 0 0 0 128
4000 109 0 0 0 0 0 0 0 0
4400 0 0 0 0 0 0 0 128 0
4800 113 0 0 0 0 0 0 0 0
5200 118 0 0 0 0 0 0 120 0
5600 0 0 0 0 0 0 0 0 0
6000 0 0 0 0 0 0 0 0 0
6400 0 0 0 0 0 0 0 0 0


So if those assumptions are indeed correct, this would indicate that my ECM is leaning out my mixture correct? All of my BLM values are below 128.

I'm 90% sure my chip is not stock (fan comes on at 190 deg F which I believe is not stock) and I don't know if that would affect this table. Can anyone shed some light if my assumptions are correct?

If my car is running rich and the ECM is leaning it out, does that mean I could have an injector leak or something like that?

Any help is appreciated.. I know this all seems basic for most of you but I wanted to at least type this up for the newbies searching for info like me.

Thanks,
-Zach

rons85

Well - yes - the BLM values are the place to look to determine how close to "correct" you are on fuel. You are somewhat rich everywhere, more so at lower loads. You'll need to adjust the pulse width in the PROM tables to correct it. Take a look at the "sticky" at the top of this forum for the last reply to it by Me - I'm also playing with my '85 and put up a Long discussion there about what I've done so far.

Welcome to the world of Tuning, BTW - now that you are Scanning/logging the next step it to gather the stuff to burn your own chips. Since you already have Tunerpro all you now need is a prom programmer. And some 27C32 Eproms. At least the '85 is a bare PROM - simple.

Most likely the chip you have isn't OEM (the fan setting is just one clue). Another thing might be the fuel pressure - do you have an adjustable regulator on it? If so you could get the BLM's closer by dropping the pressure some - you want to be careful not to get it lean at the higher loads though, it looks good there Now...

Also - what .ads (ALDL definition file) file are you using for Tunerpro? Verify the datastream locations it's using for the various ALDL data bytes - the .ads file I have isn't all correct... it's the one linked on the Moates site: 1226870_160baud_85_Fcar.ads and is the Only '85 file I've been able to find online anyplace. The link to that Moates site BTW is:
http://www.moates.net/fileman/index....%20Definitions

That same .ads file can be found several places, but it seems to be It for an '85. Once a couple of changes are made to the datastream definition (easy in Tunerpro) it's works fine. It does want to show you an "LV8" value, which is silly - that's not something that the ECM sends out... It's a calculated number based on rpm and airflow and is used in several of the tables within the prom program - it's nice to know what it is, but it isn't something that can be read from the datastream.

snowzach

Hmmm.. As I suspected I am running rich everywhere...

So, say that I did have an aftermarket chip.. Is is possible that the values put into this chip are richer than what would be considered stock? Hence the computer is trying to lean it out to compensate?

Or do you think I have some sort of fuel problem? (Regulator needs adjusted, Leaky Injector, etc) I don't have an adjustable regulator.

I did eliminate the air system and removed a bunch of vacuum lines and bypassed all that. Could that be part of the problem as well?

Thanks for the info BTW. Very Helpful.

rons85

Unless the chip was a true "custom" one that someone made up, then it won't be doing much different than an OEM chip. I have a Hypertech "thermomaster" chip that I had put in My '85 years ago - all it does (I discovered once I started playing with chip editing) is change the fan settings and the torque converter lockup. That's it - no timing or fuel changes at all.

I suspect that the Factory chip runs rich at low loads - period.

Removing the AIR stuff Might make a difference, as might the EGR. Both are gone from the motor in my car now so I can't compare. With the "factory" non adjustable pressure regulator you are unlikely to have More pressure than there ought to be, so that's probably not a cause. The '85 is supposed to have #24 injectors in there also - so you would need to be even larger than that - #30's or better - to see rich for That reason.

You aren't really All That rich. BLM numbers Ought to be nice and even at 128 - in a perfect world. This is not going to happen in real life. Numbers on the rich side are safe. Particularly at low loads or coasting/idle it really doesn't mean much - even for an emissions test since the motor really isn't moving enough air under those conditions to matter. Don't forget that the difference away from 128 is the Correction that the ECM is making. It is Correcting, afterall... at least once it warms up and goes into closed loop.