L-body TII electronics -> 87 electronics conversion

[Clay]

Ok, this is the method used to swap from L-body TII (ie GLHS) electronics to 87 TII (ie Daytona, Shadow, CSX, Lancer, Lebaron, etc) electronics.

NOTE: If you have NOT converted your L-body to TII status, then you will need to do that first, OR at the same time. The directions below assume you have already completed a TII swap.

This is really as simple as playing with 5 wires.

I. Underhood Map Sensor
You will need to add an underhood MAP sensor to use with the 87 LM. Assuming you already have the correct MAP sensor and plug, you will need to terminate 3 wires.

Looking at the MAP sensor on the vacuum barb side, you have three connections, A, B, and C.

A - left connection - This is the sensor ground. The factory wiring color is Black w/ light blue tracer. This terminated 2 different ways. (1) Splice this with #25 location on the red LM connector (this is the sensor ground wire), OR ground directly to the battery.

B - center connection - This is the sensor signal to the LM. Terminate this wire in the #19 location on the blue LM connector.

C - right connection - This is the sensor +5 volt supply. Terminate this wire in the #1 location on the red LM connector.

Your underhood MAP addition is now completed.

II. LM Connector Wire Swapping
The last step is to swap two wires from the blue LM connector to the red LM connector.

(a) Move the wire in location #4 on the blue LM connector to location #4 on the red connector (black wire w/ pink tracer). This is the check engine light wire. (You can cut the orange wire w/ green tracer out. It is no longer needed)

(b) Move the wire in location #14 on the blue LM connector to location #9 on the red connector (white wire w/ orange tracer). This is the speed sensor wire.

Now, you may want to lengthen the wires you move from the blue LM connector. I found they were about 4" short, so I spliced/soldered in a new piece so there would not be any undue tension on the wires. I also cut away all of the protective covering when I did my conversion so that I could move the wires all the way over and rewrap everything. Its a bit overkill, but makes for a much cleaner install, with less chance of issues down the road.

[vxvxAndrewxvxv]

can we post this to the knowledge center?

[Skibbe]

Maybe this is a dumb question, but why would you need/want to swap between the two? If it's already running GLHS electronics, are the Daytona tables any better?

[vxvxAndrewxvxv]

I've been told that the glhs fuel curve is pretty decent, but that the csx and others are way smoother and will give you gains in switching. I'm mostly interested because I'm looking at doing an alky injection, and I want to have the 3 bar already done.

[Clay]

The best reason (besides those vxvxAndrewxvxv mentioned) is you can make the 87 LMs socketed and then easily swap cals. The pre-87 LMs use 2 eproms for the program, so you would have to make changes to, then burn and swap 2 chips for each cal. I dont even know if anyone has done that. So the easy way is to move to an 87 LM/external MAP setup.

[mw6886]

Not necessarilly true.

You only need to burn one chip with the 2 chip cals. Most of the code is one the other chip. All the table data and constants are on one chip, the one you can see through the MAP window.

As a matter of fact, during my 3 bar GLHS code conversion, I used a 28c64 chip with a ZIF socket on an 85 computer that was converted.

The beauty of the 87 computer is that, yes, it is one chip, which makes it a lot easier, and there is a little more supprt for that. I believe I am the only one that has a working 3 bar GLHS cal?

[cordes]

Not necessarilly true.

You only need to burn one chip with the 2 chip cals. Most of the code is one the other chip. All the table data and constants are on one chip, the one you can see through the MAP window.

As a matter of fact, during my 3 bar GLHS code conversion, I used a 28c64 chip with a ZIF socket on an 85 computer that was converted.

The beauty of the 87 computer is that, yes, it is one chip, which makes it a lot easier, and there is a little more supprt for that. I believe I am the only one that has a working 3 bar GLHS cal?

To my knowledge you may be. Although there was someone else on a tread I started here a while back that was doing his own GLHS cals and it very may well have been 3 bar. As stated the primary reason to switch is that the 87 TII cals have so much more support over on moparchem.com. There is really not a ton of difference between the two IIRC. Although I may be thinking of the MP cals on that.

[supercrackerbox]

I believe I am the only one that has a working 3 bar GLHS cal?

Well I still haven't gotten to try the one you sold me, but hopefully I'll be another one in the near future.

[Keito]

Well I still haven't gotten to try the one you sold me, but hopefully I'll be another one in the near future.

I used my cal a couple weeks ago.
It's crazy!

[2.2turboscotty]

this should make things easier for me, i just got my upgrades from cindy about a month ago, head, cam, +40s, 3 bar map, etc and stage 5 '87 logic. the car is my '83 scamp that i converted to '86 T2 a couple of years ago. i am running an '86 MP stage 2 in it now and i was wondering how to change it to the '87 electronics and the 3 bar. i was looking at the plug on a '89 daytona thats out back for the map sensor and it looks close but the little slit in the connector is in a different spot, do i modify or get another connector for a different year? i had asked cindy to include instructions to do the swap but it looks like you covered it here, thanks!
scotty

[cordes]

this should make things easier for me, i just got my upgrades from cindy about a month ago, head, cam, +40s, 3 bar map, etc and stage 5 '87 logic. the car is my '83 scamp that i converted to '86 T2 a couple of years ago. i am running an '86 MP stage 2 in it now and i was wondering how to change it to the '87 electronics and the 3 bar. i was looking at the plug on a '89 daytona thats out back for the map sensor and it looks close but the little slit in the connector is in a different spot, do i modify or get another connector for a different year? i had asked cindy to include instructions to do the swap but it looks like you covered it here, thanks!
scotty

You can modify the plug, or break off the little piece in the sensor that prevents the plug from going in. I have done it both ways now. Modifying the plug has less risk of an expensive mistake, but either works well.

[2.2turboscotty]

thanks cordes, i think i will just make a little slit in the connector so it fits into the map sensor instead breaking the piece in the sensor itself. like you said less chance for a mistake.

[turbovanman²]

Words to find this again-

wiring, wire, conversion, body.