Im attempting to do this swap but this wiring stuff has me befuddled. This is my first attempt to do a swap including the fuel injection system like this before. If it was carbed I could handle it but this is a animal all itself. SO.....I have a 1994 lt1 im trying to stuff into a 88 305tpi car. I have both harnesses the 88 I got figured out....I think. The Lt harness I cant figure out though. I dont get why the black Pcm connector is called a 4 pin when its a 32 pin for instance. The wire colors arent matching up in any way shape or form.....Im just plain lost and feeling dumb. What am I missing, besides a PHD in electrical? Can someone like KISS this whole thing for me? PLEASE PLEASE......

 

This stuff was written for a LS1 harness, but the procedure is the same for LT1, TPI, or anything really

Prepping the 3rd gen half
https://www.thirdgen.org/forums/ltx-...p-3rd-gen.html

Disassembling and reworking the swap harness
https://www.thirdgen.org/forums/ltx-...rt-finish.html

Other info more LT1 specific in here to answer the hard to find questions, fuel line diagrams with PNs, relay diagrams, simplified engine schematics, Fbody body pinouts etc
https://www.thirdgen.org/forums/ltx-...formation.html

Individual LT1 schematics from GM service manuals in here along with a wealth of other info
http://www.lt1swap.com/95impalalt1.htm

The black PCM connector should be labeled C2, not a 4 pin whatever. Dont give up on the wiring, once you get the hang of it, youll love how easy it is compared to the constant adjustment of carbs

 

There is a black 4 pin connector, also a white and blue connector with 8 spots for wires in each, this is where the crank signal, oil pressure, fuel pump, temp, tach and other functions come through.

It took me a while to figure it out also, I had access to a Mitchell's Online so I could print out wiring diagrams which made it extremely easy.

Might try on shbox.com to see the wiring diagrams they have up on there.

 

Thanks for the help and encouragement! I think i have most of it figured out. I discovered part of the problem I was having is that when i removed the harness i cut the c210,220,and 230 plugs. I think i have most of them accounted for by wire color but a few are the same color but run to different things. For instance i think i have three green and white wires and they connect to three other wires but without the connector im guessing which green wire was meant to be which green wire. Im still working with the harnesses out of the car and no engine in the car so im sure some of it will make more sense once im actually installing it all. I m sure it will also bring alot more questions as well. REALLY glad i found this site!

 

yeah its really overwhelming at first, but with enough time spent learning the layout it becomes pretty simple. I'm right in the middle of making my new harness and I know how it feels.

the threads that Pocket provided (and wrote) above are EXTREMELY useful for this, as is shbox.com and lt1swap.com for schematics and pinouts. You can also take a look at my thread to see how its going there.

~Steven

 

Shbox has a TON of info, thats what finally lead me the right direction. A picture of the electrical harness with labels does wonders! On a side note from the wiring would anyone recommend a place to get a good re-ring kit from for the LT? I looked at summit and it was around 350$ which seemed kinda steep for just a ring kit. As always any and all help/opinions are appreciated

 

just completed the harness for my lt1. Thanks to pocket with his detailed threads. It looked impossible at first glance. I've never done a fuel injected swap before,never messed with wiring before, hell Ididn't even know how to read a schematic but after reading over Pockets threads a few times and having access to alldatapro I tackled the project like it was nothing. Once you get past the fear its simple. I spent about 15-20 hrs on mine. Thanks Pocket.

 

the pictures dont work whats going on? need this info

 

Photobucket is maxed out. It will reset within the week