I'm new here so if this is posted in the wrong place just help me out please. I am putting a TPI from a 87 Formula into my 69. Things are going pretty well so far but I have some question as to my dash gauges and sensors and so on. I have a 96 dash from a firebird installed with factory gauges. What hurdles will I have to jump in getting this accomplished? Before you jump in a say WOW you have really dove in deep let me say "I Know that already" and I am afraid of no challenge. Has anyone else done this kind of swap? I have a LS1 tank and fuel pump installed. Anyhow if you have any suggestions please help me out.

 

Well first off, welcome to the boards.

Second, you are not deep, just be prepared for some time consuming labor.
The fuel pump deal will be fine. You have a 90ohm sending unit that will work fine for the gauge on the cluster. The speedometer runs off the VSS, two wire hookup. Tachometer will be easy, and the rest.

Now, you will have a constant SES light unless you decide to use an LT1 computer and harness and modify that to use TPI, which has been done before. The LT1 ECM is much more user friendly for tuning too.

The key is to have accurate schematics for an LT1 and TPI car. Then it is plug and play. Labeling wires will be key.

Get some white heat shrink and write on them with pen, so when you shrink them the wire will be labeled.

I use numbers and make a key

such as 01N20

01= wire number N= ground 20 = gauge of wire

 

Thanks nelapse, I accually have already wired up most of the ecm that came with the tpi I bought which was from the 87 Formula. I have a manual to show me where the wires go and that has gone fairly smooth so far. I didn't know I could use a later ecm for the tpi. I have a wire for VSS coming from the ecm and one from the dash wiring from the speedometer that splits off into two. Do I connect one end to the ecm and the other to the vss? Also I have a tach wire coming from the dash. Where does that hook? And also the fuel sender is from a later year than the gauge, will that work without any type of modifacation? I thought I understood you to say it was compatible just to hook the wire and thats it. Also if I may bother you for another question, Does the ignition power running to the ecm require 12 volts in both the "start" and "run" positions? My system has cold start injector. Hope I'm not too much trouble here. Thanks

 

Okay,

The VSS itself has two wires. You are right one belongs to the ECM to get the VSS signal for TC lock up, or use the signal to work for the Speed limter etc. The other part is strictly for the speedo. I do not have a schematic handy so I can not tell you if one wire requires a splice or what.

Shooting from the hip My best guess is that one wire will go to the speedo one to the ECM. I am sure it wouldn't matter which one since the vss sends the same pulse to each wire.

The tach wire from the dash will hook into the wiring by the coil. I am assuming you have an external mount coil, the coil has two connectors on it. Look up the tach wire from a schematic or haynes manual. If I can remember correctly the set of wires were tan or grey, tap a wire into the tach output wire from the coil harness and run that to the dash.

The fuel sender is different from year to year but the ohms are the same 90 ohms. Connect the signal wire to the gauge and you are set. Your gauge only cares about what resistance that wire has not what sender you have.

The ECM requires power in start and run. The power should be exactly identical in both circuits minus the starter, and coil.

The cold start injector will work fine if the ECM does.

-Cale

 

Thanks,
This info helps me. I have a problem with that voltage in start and run. I put the wiring harness in from the 96, steering column and all, but I don't have a wire that has voltage in both places. I have a Yellow wire that has 12v in the start position only not in run, and I have others that have 12v in run but goes to 0v in start. I know I need the 12v running to my starter soliniod but it "must" go dead when the key is released or it will keep energizing my starter right?

Also I have a TH400 for tranny and dont have an electrical locking converter, but I do plan to use a vss from the late 80's early 90's chevy truck with th400, I understand they used a vss.

Thanks

 

Never mind on the 12v ignition issue, I found my problem and got it fixed. The plug going to the top of the steering column had slid past the terminal going to the pink wire, I bent it back into place plugged it back in and now have the power in run and start.