I have a 1986 Z-51 auto Vette and I just bought a Autoxray scanner for the car. I plan to use the scanner to read and record the engine functions during quarter mile runs. This information will then be used to help me burn new chips for the car. I am planning to swap in a 406 Miniram engine over the winter. The problem I have is that when I scanned the car I only received some of the necessary information needed to burn chips for the car. My spark advance, knock retard and block fuel trims did not show up on the scans. The scans were also very slow, to slow to actually show any usefull data. This lack of data prompted me to try the scanner on my 1988 L98 Firebird. With the scanner on the Firebird everything worked great, I received the spark advance, knock retard and block fuel trim data. I then placed a call to Autoxray and they told me that my 1986 computer was the same as the 1985 computer and it does not transmit the data that I require to burn chips. They told me to switch my computer to a 1987 - 1989 computer and chip, then I would receive the information that I was looking for. I thought all 1986 - 1989 computers were the same, they are the same in the F-bodies, are they different for the Vette? I do own a 1987 L-98 computer out of a GTA Firebird can I just swap this computer for the 1986 Computer in my Vette, and put in a 1987 Vette chip? What is required to make a computer change to the later model (assuming Autoxray is correct)?

Sorry for the long post?

Thanks, Brian

 

Thats a bit odd...I can see everything on my 86 TPI with my snap on scanner..but when I plugged it into a 1985 Vette, there was very little info.I do have the late 86 with aluminum heads and maybe I have a different ecm,but not sure.Is your vette the early 86 with cast iron heads?
As far as I know you should be ab to swap ecms from 86-89 cars unless someone correct me on that.
Does your car have the original ecm in it?
maybe someone swapped in the wrong one but it still runs and drives fine?Just wont show you the readings you need.

Or maybe the scanner you have is programmed wrong..did you set it for the 85 model year by accident?
Just throwing ideas...doesnt make sense what they told you..you should be able to see the knock counts,blm and integrator numbers etc.
From what you wrote,it sounds like an 85 system that wont show up info you need.

 

My car has the cast iron heads, so it is an earily 86 model. I had the scanner set for 1986, I checked it twice to make sure. The computer acts like it is the 1985 model and not the 1986 model, maybe somone switched the computer to a 1985 model. Does anyone know the part number of the 1985 computer and 1986 computer?

 

I doubt that somebody swapped ECM's on you, because the '85 and '86-'89 ECM are not plug-n-play between the two..... there would have been some re-wiring and other parts involved.

Pull the ECM down from under the breadbox area, the '86-'89 ECM will have Service Number 1227165 on it, and the '85 will have 1226870. The '85 will also have the cover for the eprom near the end of the ECM while the '86-'89 will have the cover in the middle. Look at these pages to see how to drop the ECM and also notice that this is an '85 ECM, so you'll see the difference in yours and the '85 when you pull yours.
http://members.dencity.com/marcho/flashnet/1985ecm.html

 

Good to see craig posted that..hes pretty much got the 85 set up all known by now through all the work hes done on his previous car and proms he made for the 85's.
I wasnt sure if the 85 could be swapped out without some good wiring work.

Just an idea...why dont you set the X ray scanner for an 87 TPI?I cant see it hurting anything..if the ecm you have is correct, it should show the stuff you need.The 86 and 87 are pretty much the same.

Just thought..maybe they programmed the 86 as/like a 85 into the xray scanner and wont look at certain things.

Im not familiar with the Xray set up so im just guessing.
Let us know what you find.

 

I did try setting the Autxray to 1987 to see if it could read the chip, it could not.

 

I'm currently searching the free software choices for my laptop to scan my '85 'vette, and have discovered the '85 transmits data at 160 baud while later models use a faster rate...somewhere over 8000. That might be what the problem is.

 

Brian,
Let me know if you ever get anything sorted with AutoXray. I can't even get mine to do a sucessful link on my late '86. Works fine with Diacom+. The AutoXray does work with my Jeeps. I haven't tried contacting AutoXray, but would like to hear from those that have gotten it to work on their '86 Corvettes.


[Modified by Ray Quayle, 8:58 AM 10/20/2001]

 

Actually started my car today. First time since mid May! Turns out AutoXray does link to my '86. The problem is the data is not correct. For instance if you monitor PROM ID, it fluctuates all over the place. VSS reads 5mph while stopped, INJ PW reads 0 while idling smoothly, stuff like that. No data point is correct. I knew there was a problem with AutoXray and the '86 Corvette, but had heard some folks got it to work with a patch from AutoXray. I'll need to contact them. When selecting '87 or later, it won't even scan which is a bit strange, as the ECM is the same. I'm at a loss. I know the ECM will run in either 160 baud or 8192 baud, but not sure what mode AutoXray runs in. I suppose I should check the resistance it sends the ECM on pins A-B of the ALDL to know for sure though.

 

I am having the exact same problem with my XRAY on my 86, I have had very good results with a 90 model I had but it wont read my 86. I sent the unit back and they just returned it and it's the same, no change??? I get readings referring to "transmission govenor" etc. things I never saw before. I contacting them again this week. Your description is the exact same t hing I getting, 5mph standing still, prom id is all over the place.....

 

I found the problem with my slow scans, missing scan information and wierd drivability problems (torque convertor locking up in second gear), it was the stock 86 chip. I replaced the stock chip with the one of my many spares for my 1987 L-98 GTA Trans Am and all of my missing information showed up and the drivability issues disappeared. I now can retreive 41 different pieces of information with my Autoxray, with the stock chip all I had was 26 different pieces of information. My wierd torque convertor operation has now disappeared, the torque convertor will only lock up in four gear at lite throttle loads above 45 MPH. The car feel completely different (almost new) I can not believe how much better drivability is with the 1987 GTA chip.

To get the car to scan correctly with the 1987 chip I set the Autoxray to 1987 Corvette and it worked perfectly.


[Modified by bjankuski, 4:25 AM 10/22/2001]

 

I had similar problem with my Auto Xray so I called the Auto Xray tech support and the person I spoke with said that for some reason thier product does not interface well with the 86 computers. My scanner was showing a knock problem, that I couldn't figure out. My mechanic used his snap-on scanner, which showed no knock?

Also GM went to a different ECM in 87 so the 86 ECM was only used for one year, that caused me to be suspicious.

 

I'd love to know what ECM GM went to in in '87. My parts book shows the 1227165 ECM used from '86-'89. The 16198259 was an update for the 1227165 , but is functionally the same.