OPSU Issue
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Car: 92 Camaro Z
Engine: 350
Transmission: Built TH350 with 3200 stall
Axle/Gears: 4th gen, 4.10
OPSU Issue
Hello,
My engine block doesnt have the OPSU installed; instead there is a plug in there which is stripped out and cannot be removed. Somehow i missed this as i was rebuilding the engine. Given the location its impossible to get any type of tool in there to remove it.
Is there another spot on the block i can locate the OPSU sensor and get a reasonable reading from the sensor? Or is there anything else i can do get an oil pressure reading?
thanks for the help!
My engine block doesnt have the OPSU installed; instead there is a plug in there which is stripped out and cannot be removed. Somehow i missed this as i was rebuilding the engine. Given the location its impossible to get any type of tool in there to remove it.
Is there another spot on the block i can locate the OPSU sensor and get a reasonable reading from the sensor? Or is there anything else i can do get an oil pressure reading?
thanks for the help!
#3
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Car: 92 Camaro Z
Engine: 350
Transmission: Built TH350 with 3200 stall
Axle/Gears: 4th gen, 4.10
Re: OPSU Issue
If i can use the china wall as a alternative, can you tell me where its at so i can go with that?
Thanks
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Car: 86 IROC
Engine: 350 Vortec TPI
Transmission: 700R4
Axle/Gears: BW 3.27
Re: OPSU Issue
The china wall is the part of the block that meets the intake at the front and rear(under the distributor and under thermostat). The plug near the filter is there as that is an extra oiling port. The OPSU is normally at the top near the china wall.
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Car: 86 IROC
Engine: 350 Vortec TPI
Transmission: 700R4
Axle/Gears: BW 3.27
Re: OPSU Issue
I have a parts car that was an original z car 305 tpi, and it had the pressure sensor and separate FP cutoff sensor T'd on the china wall. I think that is how most of the earlier cars are as the harness on the car was not cut or rerouted. I thought that only v6 cars had the OPSU above the oil filter?
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Car: 86 IROC
Engine: 350 Vortec TPI
Transmission: 700R4
Axle/Gears: BW 3.27
Re: OPSU Issue
Agreed that the early and later have 2 and a 1 sensor respectively. Could it be that the difference is for export?
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Car: 92 Camaro Z
Engine: 350
Transmission: Built TH350 with 3200 stall
Axle/Gears: 4th gen, 4.10
Re: OPSU Issue
I should have given details on my car in my first post (sorry about that)
Car was a TBI car but the engine is a 350 crate motor from 86'. The car is now carbed so im not too concerned about the OPSU activating the fuel pump but i want to have an oil pressure reading on the gauge. The wire for the OPSU has three or four wires on it.
If i hook the sensor up to the back of the china wall, will it give me an oil pressure reading on the gauge?
thanks for the help guys!
Car was a TBI car but the engine is a 350 crate motor from 86'. The car is now carbed so im not too concerned about the OPSU activating the fuel pump but i want to have an oil pressure reading on the gauge. The wire for the OPSU has three or four wires on it.
If i hook the sensor up to the back of the china wall, will it give me an oil pressure reading on the gauge?
thanks for the help guys!
Last edited by patricklav; 05-30-2013 at 12:57 PM.
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Car: 86 IROC
Engine: 350 Vortec TPI
Transmission: 700R4
Axle/Gears: BW 3.27
Re: OPSU Issue
Yes. Whether you put the sensor at the oil filter or at the china wall, they are both oil passages that are pressurized.
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Car: 92 Camaro Z
Engine: 350
Transmission: Built TH350 with 3200 stall
Axle/Gears: 4th gen, 4.10
Re: OPSU Issue
I'm very confused now. When I check behind the distributor from the driver side the only hole I see is the hole facing the transmission. I missing something here?
Thanks again
Thanks again
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Car: 91 formula ws6
Engine: 355 tpi OBDII
Transmission: 4l60E
Axle/Gears: 2.73 with 4th gen brakes
Re: OPSU Issue
Its to the left of the distributor or closer to the brake booster. It may have a pipe plug in it. All the later vortec trucks get there senders put here.
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Car: 92 Camaro Z
Engine: 350
Transmission: Built TH350 with 3200 stall
Axle/Gears: 4th gen, 4.10
Re: OPSU Issue
I found the hole - it had a flush mount pipe plug (1/8 npt) in there as well as a little bit of rtv on it. it came out no problem.
Thanks for the insight and pics guys.
I had bought a OPSU several months ago but the thread is 1/4 NPT, as that is the stock size for a 92. It has the correct connector to attach to the pigtail (3 wires), however all of the opsu's with 1/8 NPT only have a single wire connector.
Can i use any SBC opsu with 1/8 npt thread?
Which of the 3 wires would i connect to the single connector on the opsu?
Car is carbed so i only need a gauge reading, and not send power to fuel pump.
thanks again.
Thanks for the insight and pics guys.
I had bought a OPSU several months ago but the thread is 1/4 NPT, as that is the stock size for a 92. It has the correct connector to attach to the pigtail (3 wires), however all of the opsu's with 1/8 NPT only have a single wire connector.
Can i use any SBC opsu with 1/8 npt thread?
Which of the 3 wires would i connect to the single connector on the opsu?
Car is carbed so i only need a gauge reading, and not send power to fuel pump.
thanks again.
#16
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Car: 86 IROC
Engine: 350 Vortec TPI
Transmission: 700R4
Axle/Gears: BW 3.27
Re: OPSU Issue
On the three wire unit it will be the middle terminal(tan wire). You may be better off getting the single wire sending unit that came on the earlier TPI and SBC motors.
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Car: 92 Camaro Z
Engine: 350
Transmission: Built TH350 with 3200 stall
Axle/Gears: 4th gen, 4.10
Re: OPSU Issue
Its not hooked up yet (need a 90 degree adapter), but should that tan wire be hot? Currently my gauge is pegged out all the way to the right and im seeing volts at the tan and orange wires.
thanks
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Car: 86 IROC
Engine: 350 Vortec TPI
Transmission: 700R4
Axle/Gears: BW 3.27
Re: OPSU Issue
If i am not mistaken you will see voltage on the orange. The orange is a 12V hot when the key is on to activate the fuel pump if the relay were to burn out(the gray in the three wire plug is to the fuel pump). The tan is to the gauge. Not 100% sure if you should see voltage, but you may. I would think that your gauge would be reading 0 with nothing connected and full when completely grounded to body. Opposite of what you are experiencing. I once had a temp gauge that would get stuck at full when you go to start the car and it does its sweep. Possibly similar issue to what your having?
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