So whats the concesious on BLUE 20, RED 12, and BLACK 5? Im not using the opti harness to wire in my cam/crank sensors so wouldnt Black 5 be deleted aswell?

Just to double check since lethal or myself isnt odbII we would put lt1 pcm Blue 30 Serial Data into LS1 pcm Blue 58 and then when we switch out our port for a obdII style port we make sure that the purple wire (obdII) goes into the tan wire (obdI)? Does that make sence and would work?

 

^ I believe you correct on blue 30 and putting it in blue 58.

 

That will work.

I avoid doing this in a new harness build because you can only image the confusion it would cause when someone looks at the harness and schematics. For that reason, I always supply the OBDII connector as part of the new harness and don't include the TAN serial data wire.

But if I were reworking a used harness, I suppose I would consider that it would be convenient that there is already a (TAN) wire going from the PCM to the diagnostic connector and reason that it would be simpler in that situation to avoid running a new wire.

 

Sweet! Thanks for clearing that up Mike. So now were all left Red 12 and Blue 20. What are these used for and can they deleted? After that i think all three of us are good to go and can pretty up the harness and put it back in the car!

 

I think I accidentally cut the tan serial port wire. Oh well I'll fix it tomorrow.

 

LT1 RED 12 is a throttle position signal connected to the EBTCM (Electronic Brake and Traction Control Module). I have tried to track down a GM engineer for more information, but my GM source was not able to provide more details than what is available in the service manual (which is next to nothing). Because this is a throttle position signal, I would assume it is the same 0-5V as used with the BLUE wire of the throttle position sensor. However, that would be redundancy in the harness and not typical of a GM harness. It's a TAN/BLK wire as well. So I don't know what this wire is all about. My best guess is that it is a different (not 0-5V) throttle position signal from the PCM to the ABS module for ABS functions. Since all F-Body customers who have provided feedback don't use this wire and report that their ABS still works, it leaves me scratching my head about it's use. Regardless, the LS1 PCM doesn't support it, so what else are you left to do but to leave it out?

LT1 BLUE 20 is the "Output/Field Service Enable" circuit. This is commonly used with OBDI systems as a scan tool "mode select" function as it is connected to cavity B of the OBDI diagnostic connector. For F-Body with OBDII connector it goes to cavity 6...even with true OBDII vehicles (1996-1997). Before I make this complicated...it's an input from the scan tool to the LT1 PCM. The LT1 PCM goes away, so does this wire.

 

Fantastic! Thank for all the very helpful info Mike!

I think were all done with the left over wires and our harness's are all in prime shape to be reinstalled. I have to wait till spring time to see my car again but hope to see how Lethalbird and 355z28 make out

 

It may not be pretty but it's mostly back together.

 

I think it looks awesome! have you gotten your ecu tuned yet?

 

^ I still haven't. I've narrowed it down to speed inc, ion, pcm4less, or frost though. I just need to make a few phone calls.

 

I emailed speed inc with no return email. I also emailed IOn and he got back to me saying he could but hasnt gotten back to me with any specifics.... i really need to figure it out

 

I was recommended speed inc by someone one here and i think bolo is using ion for his start up tune. I know camaro Corey used efi alchemy. And cranberry used frost.

 

I am using Ed Hutchings for my initial tune. He is also a sponsor on the forum. I have heard nothing but good things about him.

 

^ I've never heard of him.

 

The individual who has tuned the most 24x conversions to-date is Jamy at http://www.smokeysdyno.com in North Canton, OH. He can offer mail order starter tunes.

 

Ed does tuning on LT1 and LS1 platform. I needed someone that could do a 3 bar SD tune for me and from the companies I talked with Ed fit into what I was looking for in a tuner. I don't know if he does mail order tunes. I have EFI Live so he is just emailing the tune to me. If you want to contact him his screen name on here is edcmat-l1.

 

I just talked to Ed a little bit as well. He seemed very confident in tuning my setup. Is willing to work over email with HP tuners with me. Although the tune is more expensive then a standard mailorder He will exchange datalogs and tune files until it is dialed in. Thats service I can't complain about.

Lethal get that thing going! I want to hear it going so Im motivated to keep movin on mine.

 

ThThat's what I liked with the service from Ed. Its not just here is your tune. He helps to get it dialed in and it gives an opportunity to learn about tuning.

 

Obd port is in. I noticed that on mine I had a purple wire in cavity 2 but I didn't see it on the schematic.

 

your car was a 94 right? Mine being a 96 I shouldnt have to mess with the OBD port