I want to do the bare min for the wiring harness. I want to run all mechanical guages. will the computer still work fine if i dont hook up the oil press, water temp ect... What are the basic few wires that in the 95 harness that i have to splice into the 73 camaro's harness to get the engine to run fine?

 

Gauges are not computer controlled (except for the tach). No worries, there. All you need is proper +12v, ground and all the sensor inputs to the PCM to make it run. There are PCM pinouts on my Tech Page, if needed.

 

The oil pressure, water temp, system voltage and fuel level gauges are not driven off the computer. The oil pressure comes off an electronic pressure sensor on the back/top of the block (mid 94 - 97 LT1). Coolant temp comes off an electronic temp sensor in the driver's side head. Volts come off the alternator (indirectly), fuel level comes directly from a float activated sensor in the tank.

If you chose to use mechanical gauges, you would need to install a temp sensor bulb and capilary tube in the head port, tap into the stock oil pressure sensor location on the block, or the spare port in the block above the oil filter and run a braided SS line to the dash. Fuel will be driven off your stock tank sensor. Voltage is obviously still wired, not mechanical.

In the LT1, the PCM drives the tach (except for 93). You can drive an aftermarket tach the same way. The LT1 drives the speedometer electronically off the PCM. You have to decide what transmission you are using. To keep an electronic speedo, you need the electronic vehicle speed sensor on the tailshaft of the tranny (either the 4L60E or the T56). If you chose to go mechanical on the speedo, you will need to adapt a gear drive to the tailshaft of those trannies.

The PCM does not get fed any info regarding oil pressure or fuel level. It reads system voltage off the power supply to the PCM. It take coolant temp off an electronic coolant temp sensor in the water pump housing. The PCM will not be able to control the engine (spark or fuel) correctly without the coolant temp input. The PCM will need to be programmed with your rear axle ratio and the tire diameter. Getting a custom made harness from an outfit like Painless will make the harness interface a lot easier.

You will need a complete PCM and wiring harness for the year LT1 engine you pick. The harness is specific to whether the tranny was an 4L60E or the T56. The PCM program must be flashed to match the tranny type.

The engine will run fine with the PCM and harness. It doesn't need any other info from your 73. If you attempt to add a check engine light, or to mount the diagnostic port in the dash, you will need to extend the wiring into the cockpit.

How do you plan to provide the 43.5psi recirculated fuel supply that the LT1 requires?

 

That was exactly the info i was looking for thanks. As for the fuel i am going to attempt to use the tank from my 95 ta(donor car) and mount it in the trunk. That way i can keep my racetronix harness and walbro pump. It doesn't matter what i have to take off the ta as it is a lost cause and im scrapping it.

 

Oh ya and ill be running the muncie 4speed that is already in the 73 camaro.