Wierd figures when viewing bins for the $83A mask

Alright, I am not really interested in doing any serious tuning on this little turd ('91 S10 LN8 2.5 5 speed), but I gotta keep it running until I'm ready to swap engines. It recently developed some drivability problems that I believe to be MAP sensor related and I want to hook up the laptop and look at the data stream to diagnose the issue. I already had some bin files and definitions for Tunerpro because I had removed and disabled the EGR system a few years ago. I have been running the stock memcal for a long time now since it rarely set EGR codes so it has been a couple years since I even opened up a bin and looked at it.

Anyway, to cut to the chase, I have opened several bins and used several xdf's downloaded from here as well as using TPv4 to view them and all look the same. A lot of the values look really odd such as the timing reference angle being 89.75 degrees and the timing values in the main spark map go up near 60 degrees. I don't recall the values being so wacky a few years back when I disabled the EGR and made a few tweaks to some of the tables, but a lot of time has passed since then and I do not have a copy of the modified bin now. I did notice that if you use the graph view function when looking at the fuel and spark tables the graphs look typical if you ignore the numeric values. I'm just curious as to why the values look so odd so that I can interpret what I am seeing. I'll attach a bin and xdf that I downloaded and can verify that other bins and xdf's look the same. Thanks in advance,

Phil

Bump. Somebody ? Anybody ?

Sorry, must have mised your post?

AXAA is $83. But I'm not sure it looks right either with Mask $83A2? Is there another mask? Did you look through the TunerPro Lookup?
http://www.gearhead-efi.com/Fuel-Inj...our-files-here!

$83A looks good, there are some strange tables if I remember right about this engine is DIS? There is a 20* spark Bias that is not reflected in Spark Advance table so take out 20 and it looks right.

If there's a 20 degree bias not reflected in the tables then yes that makes a little more sense. But no the engine isn't DIS . It is an Iron Duke and some of the later car applications may have had DIS, but the trucks always had a dizzy. I do know that the pickup in these distributors had a conventional magnetic pickup and an optical as well. I'm not sure why exactly though. I think that the use of the optical pickup was why they used a '165 ecm though as there weren't any other 4 cylinders that used them. The other odd value was the spark reference angle being 89.75 degrees, but that may have something to do with the optical pickup. Thanks for the reply though, it makes me feel a little better about the wacky value. Oh, and I had named the xdf $85A2 because I had other files named $85A. Sorry for the confusion though

That is strange... we have another thread, long, about 4 cylinder ideas and I was under the impression the Optical wheel you are talking about was used for a 1X signal to DIS. Now if you have a distrutor and TBI, I'm wondering why the use of this special distributor and the spark reference angle? There are pics of it in that thread as well. We ended up using an external crank trigger wheel along with the four cylinder DIS...

http://www.gearhead-efi.com/Fuel-Inj...RE-with-GM-ECM

Quote:

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Originally Posted by pmkls1

Oh, and I had named the xdf $85A2 because I had other files named $85A. Sorry for the confusion though

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SInce we were talking about $83A I'm really confused now! :laugh:

But understand...

Lol, I was posting from my phone so I must have hit the wrong keys.

I still haven't read through that entire thread, but I did see the pic and that is the correct dizzy. It has a typical GM style magnetic pickup and a hall-effect sensor (not optical like I originally stated) as well. It's the only GM setup of it's kind that I know of and I have no idea why. It uses a single injector TBI and other than the extra sensor the ignition is a standard electronic distributor type. As I stated before, it is the only 4 cylinder that I know of that uses the '165 ecm and I seem to remember being told it had to do with the extra sensor in the distributor. I'm curious as to why the unusual setup, but I'm only keeping this engine alive until I'm ready to swap in a 350.

My 2 cents worth. Back then the old truck TBI had a bad problem with odd drivability problems that were from the distributor base corroded to the block. The optical sensor also had problems along with the typical module failures. To see this, you have to remove the distributor from the block and clean off the rust/corrosion. it is a ground plane or ground voltage rise.
The data reading odd values is from the incorrect data stream selected for the truck calibration you have. Back then GM updated the old 2.5L (which had 2 VINs for engines) by releasing a 92 mem-cal to be placed in a 90 or 91. This was common back then with truck and a sticker should have been used to ID. Well stickers fall off. I would suggest you find a person/shop/dealer with a Tech-1 ECM cartridge or Mass Storage Cartridge and enter a 92 MY, engine VIN or Fuel select like TBI, you have and try the other TBI Engine VIN to discover which calibration you have in your truck. Then you can download the right data stream to use for Tuner Pro. It may seem like a pain but this is the only way I know of without using the ID from the Mem-cal and using the OLD GM system now closed.