Here are my DFI fuel and spark maps. http://members.aol.com/tunedport350/images/fuelmap.jpg
http://members.aol.com/tunedport350/images/sparkmap.jpg

If you are interested you can download the complete Zip file from this link http://members.aol.com/tunedport350/files/maps.zip
Included in the Zip file is a Readme file which tells all about my car/engine combo. The Zip file contains 7 files.

"Readme.txt" = describes my car/engine combo.

"Bill" = the Calmap file (put into "unvrsl" directory to open using Calmap)

"Data1" thru "Data5" = some data I collected using Calmap data collection (these files can be viewed using "Notepad" or any other text editor.

I did encounter one problem when I was calibrating my fuel map and I am curious if anyone else ever had this problem. For some reason when I try to tune the fuel map using the O2 sensor input I have a problem that the ECU never sees an output from the O2 sensor above 0.806 volts. You can see this in the Data1 thru Data5 files. I know for sure that it is not the sensor or wiring because if I reinstall the GM ECM I can read voltages above 0.806 volts at WOT. I am certain that it is either a problem with my Accel ECU or the jumper board which I purchased which may have too much resistance on the O2 sensor input line. I would appreciate any and all feedback about this issue, even if you can tell me that you CAN read above 0.806 volts.

I was able to successfully tune the fuel curve using the knock sensor. Basically I just kept adding fuel in the fuel map until no knock was detected. You can see that in "Data1" there is quite a bit of knock and that by "Data5" I resolved this. I kept the spark curve as a known constant. (I was able to proove out that this curve worked best with my setup by using some custom proms in the original GM ECM)

[This message has been edited by TunedPort350 (edited September 27, 2000).]

 

I'll have to check it tonite, on my way home. I'm pretty sure it does go above .806V.

I checked it earlier today. I didn't see any values above .806. As a matter of fact I only saw one value of .806 in about 15 minutes of recording. It's possible that the conversion routines for displaying on the screen are not that accurate. How does your stoic meter read on the base fuel map? Is it centered or off to the right/left? I used that meter to calibrate my fuel table. I apparently have a vacuum leak again because my O2 readings are all over the place. Keep us(me) posted.

Bob

[This message has been edited by RCR (edited September 28, 2000).]

 

That was my biggest complain about the DFI .......WOT tuning . I found it very hard. Absically todo it right you have t o dyno the car wit ha wideband O2 A/F meter.
After paying someone to tune my car on the street and then was supposed to tune it on the dyno. I never did get it done all the way. I swappws back in my 85 ECM and the car ran decent.
Thats was one of the main reasons I swapped in the 7730 ECM. I have tuned that very well all around even for WOT. I use the mid to high 800mv reading for that (I know some may argue its not accurate in that range) but it usually works on most apps.
So I dont think you have any porblems. Its just a DFI thing.
Dennis

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85 vette,383,miniram,ZF6,4.10's..best ET 11.81@117.00 60' 1.65
http://geocities.com/bowtie8

 

Ahh, what a relief! I was pulling my hair out this summer trying to tune for WOT. I am glad that I'm not the only one I did a little test with mine to check the O2 readings. I couldn't get anything over the low .8's (don't recall the exact number) even after dumping enough fuel in the map to bog and blow black smoke. After verifing that with three different O2's (two heated, one not) I was starting to think that it was my ecu.....then I swapped in another ecu and then verified the numbers again...they were the same.

 

Well guys I think that we have found a problem here, either with the Accel/DFI ecu or the jumper board which connects the factory wiring to the Accel/DFI ecu. You all do have a jumper board right? If so I am curious who you guys bought yours from, then if we all bought them from D.W.R. we should contact them next.

I also have an AutoMeter air/fuel ratio meter installed which I tried to use to tune the fuel map and guess what....same thing nothing above the low 800mv. When I put the GM ecm in it does read to full rich 1volt (1000mv).

That is why I have think there is too much resistance on the O2 sensor line caused by one of the two above stated.

I think it is safest to tune WOT fuel using the knock sensor like I said earlier. The one thing I don't like though is that if we are receiving incorrect lower (leaner) voltages from the O2 sensor all of the time (even during closed loop normal driving) than we are all running too rich all the time.

 

Yes I have spoke with the DFI reps and many of the programmers. They all suggest to use a wide band lamba reader. Seems most cost close to 1500.00 this is were the felpro system looks good for 2000.
Yes I had the white racing jumper as well. Well now I repinned it for hte 7730 ecm. So I can switch from the 7730 back to my 85 within about 10 min. a couple of under hood unplugs but that it. Hmmm I have swapped back though and have no plans to. Let me say the 7730 converson is a nice way togo. ecm are about 50 bucks from the juckyard. Chips are cheap. buy 5-10 chips . I was running the DFI on a 386 and while linked the screen loading was so slow. Same for the rest of you .
I still may have a couple of my dfi logging runs. I also have a couple maps if you want to check out. Any specific spot to upload them??
Dennis

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85 vette,383,miniram,ZF6,4.10's..best ET 11.81@117.00 60' 1.65
http://geocities.com/bowtie8

 

I am not using a jumper board. I went from TBI to TPI, so I rewired mine directly to the DFI pinouts. Just because a reading of .80x is the highest reading possible, doesn't mean that the DFI doesn't pick it up as full rich. Without knowing the details of the circuit, the DFI probably has a lower input impedence which pulls the O2 voltage down a bit. Hopefully they take care of that in their software. I would consider .80x as rich, or where you want to be WOT.