Is there an Oil Pressure and Water Temp. output signal on 95 LT1 PCM ?

[lionelhutz]

The gauges use their own sensors that are completely separate from the fuel injection system. An LT1 typically had the coolant temperature sensor in the side of the passenger head and the oil pressure sensor in the port at the back of the block just behind the intake manifold. The EFI system uses the coolant temperature probe that is installed in the water pump.

[nchittman]

I know the oil pressure sensor is connected to the engine pcm wiring harness but there is no output wires for the oil pressure gauge on the harness.
I will try talking to Tech Rods tomorrow at lunch and see what they say about tapping into the wires to feed the gauge cluster. I have already printed the wiring diagrams for the s10 so I can tie them into

As for the Coolant Sensor I try to find the right connector for the sensor and put into the passenger side cylinder head like lionelhutz mentioned.
This where I had my mechanical temp gauge located.

Thanks for the replys

[RobertISaar]

i'm looking at the diagram of a 95 camaro LT1 and i'm not seeing an oil pressure input to the PCM, just one for the guage. i'm not seeing it in the corvette application either.... oil temperature shows up for that one though.

[lionelhutz]

I agree, oil pressure was definitely not an input to the PCM. Is this connection down by the oil filter? That's where the Vette had the oil temperature probe installed.

[nchittman]

I did not see the oil pressure sensor either on the pcm diagrams just thought I had missed it. Would it have some thing to do with Oil Life /Oil Change light. I think these cars had that feature. Maybe it the temperture that I'm thinking about.

The connection is on the oil pressure sensor at the back of the block on the driver's side.
Down near the oil filter is where I had the mechanical gauge connected. Hopefully Tech Rods can fill me in.

Here is the link to Techrods 94-95 LT1 wiring harness if your interested.
http://techrods.com/Products/Engine%...4-95%20LT1.htm

[lionelhutz]

Taking a quick look, it appears to be a oil pressure switch (not sensor, switch) connector. On the early GM fuel injection stuff they put an oil pressure switch across the fuel pump relay. There has been many a thread about this switch being used to control the fuel pump once the engine is running but I have never seen any evidence of that being true. From my experience, it is simply a backup to the fuel pump relay only and I've eliminated it without any issues. I didn't believe it was ever used on a LT1 but it may have been on the early years.

[RobertISaar]

There has been many a thread about this switch being used to control the fuel pump once the engine is running but I have never seen any evidence of that being true. From my experience, it is simply a backup to the fuel pump relay only and I've eliminated it without any issues.

both, really, in every application i've inspected the schematics for. i'm sure there will be exceptions though.

once the engine is running and oil pressure rises above the ~4PSI threshold, the current used to drive the fuel pump is shared between the relay and the oil pressure switch. if one of them fails, the other takes all of the load and the engine continues to run.