fittings for oil pressure and temp gauge on ls swap?

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dangOl'dodge

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hey all, recently got my ls swap in the 87 chevy r10 working.. a few weeks ago i seen a topic that had all the parts numbers and stuff listed for getting the gauges to work, i can't seem to find it!

anyone have any info on getting the stock temp and oil press gauges working in the 87? i kept a wire for the oil pressure when i reworked the harness, can i just splice that into my oil pressure gauge?

also, i thought i seen online that people were putting there stock temp gauge fitting from the 87 engine on the passenger side head of the ls motor and just running a wire from that to the gauge inside the truck, any truth to that or do you need an adaptor between the fitting and the block?
 

foamypirate

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For the oil pressure gauge, you can get a 16mm to 1/8npt fitting to go in the stock Ls oil sender location. You can then use a brass Tee and a stock 87' oil pressure sender (get the 1/8" version).

Here is a link to the adapter I used:
http://www.amazon.com/gp/product/B00062YVKW?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00

For coolant, you can use a 98' LS1 Camaro sender in the driver side head. It has 3 wires, 2 are for the ECM, and the 3rd is for the gauge. It won't match EXACTLY with the temperature on the gauge, but it is close.
 
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dangOl'dodge

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For the oil pressure gauge, you can get a 16mm to 1/8npt fitting to go in the stock Ls oil sender location. You can then use a brass Tee and a stock 87' oil pressure sender (get the 1/8" version).

Here is a link to the adapter I used:
http://www.amazon.com/gp/product/B00062YVKW?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00

For coolant, you can use a 98' LS1 Camaro sender in the driver side head. It has 3 wires, 2 are for the ECM, and the 3rd is for the gauge. It won't match EXACTLY with the temperature on the gauge, but it is close.


so what was the purpose of keeping the oil pressure wire when i reworked the harness? wouldn't using my stock oil sender eliminate the need for that wire?

and for the 91 camaro sender does it come with the wire harness?
 

74propu

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the ecm needs a oil presser input or it will shut the engine down .I left the stock ls sender in place for the ecm and taped the bypass just above the oil filter and ran my gauge there .you can get the ls Camaro temp sender and pigtale at any auto parts store I think I gave like 10 bucks for my pigtale
 

foamypirate

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the ecm needs a oil presser input or it will shut the engine down .I left the stock ls sender in place for the ecm and taped the bypass just above the oil filter and ran my gauge there .you can get the ls Camaro temp sender and pigtale at any auto parts store I think I gave like 10 bucks for my pigtale

Hrmm, I'm not sure the ECM actually does require an oil pressure input. I've seen plenty of swaps without the OEM sender. I'll have to do more digging.


UPDATE:
Oil pressure sensor signal is not required by the ECM for operation unless you want to view oil pressure via a Scan Tool. So that gives you two options. Tapping the oil cooler block off to 1/8th as 74propu suggested (which I didn't have, since my engine came with an oil cooler), or using that Autometer fitting and running the Squarebody sender on that.
 
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chengny

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The oil pressure switch used in the fuel pump relay circuit of a TBI system is only there to provide power to the pump in the case of a relay failure.

Normal operation:

When the key is turned to RUN, the ECM energizes the FPR for 2 seconds. This is to pre-prime (i.e. pressurize) the TBI system and reduce cranking times.

If - after that two second interval - the engine has not started, the power supply from the ECM to the relay is shut down.

When the key is moved to the START position, the engine is cranked over. At that point, the ECM begins receiving a pulsed reference signal from the distributor. When that signal is sensed, the ECM once again energizes the FPR.

The FPR pulls in and supplies battery power to the fuel pump.


Operation in the event of a failed fuel pump relay:

The oil pressure switch for an engine equipped with TBI is set to close at a much lower pressure than the switch used in a carbureted engine.

A TBI switch closes at 4 psi and a carbureted engine switch it closes at 10 psi.

So, if the FPR - for whatever reason - fails to supply the fuel pump with power, the oil pressure switch takes over.

Just the cranking speed provided by the starter motor is sufficient to develop over 4 psi in the lubrication system.

At that point (when oil pressure exceeds 4 psi), the oil pressure switch closes and begins supplying an alternate source of current directly to the fuel pump. This allows the fuel pump to continue to run (and supply the TBI with fuel) - even without an operational FPR.

From then on - as long as sufficient oil pressure is maintained - power to the fuel pump is available through the closed contacts of the oil pressure switch.



A couple of pages from the 1987 Light Truck Driveability & Emissions Manual - to help explain what I mean:

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dangOl'dodge

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does anyone know if one of those plugs would be on my donor truck or another truck like my 01 silverado in a scrap yard? not having much luck locating one... someone said there might be one on the coolant level sensor but i can't seem to find the plug.
 

dangOl'dodge

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so how do i wire this camaro temp sender? i ran grey to grey, black to yellow and blue to the green wire with the sleeve type connector, assuming thats the temp wire
 

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