Author Topic: Oil Pressure Gauge: 79 TA 400 4 Speed  (Read 183 times)

Jolo

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Oil Pressure Gauge: 79 TA 400 4 Speed
« on: May 04, 2021, 09:39:11 AM »
My oil pressure gauge shows 10 lbs with key off.  When I turn key on it drops to zero and stays at zero with engine running.  I just installed a new oil pump.  I repaired a frayed section of the sender wire, but that did not solve the problem.  With key on, I grounded the sensor and the gauge pinned far right.  When I disconnected the ground, and turned key off and on again, the gauge dropped to zero.  Before I pull the dash panel and run a jumper from the gauge, I thought I would ask if anyone has experienced the same condition.

Thanks

firebirdparts

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Re: Oil Pressure Gauge: 79 TA 400 4 Speed
« Reply #1 on: May 04, 2021, 10:56:25 AM »
I think the gauge itself is defective.  You should have zero showing with power on and the sender wire grounded.  It's sort of backwards, but since it's not doing anything with the engine off, then that might say the sender is also suspect.  The gauge, though, for sure, is not working at all correctly.
I want to be like Paul Kenny when I grow up
Joe Bays
1977 Y82 4-speed (red interior)
1978 Skybird 350
1978 Redbird 305
1979 Redbird 301 4-speed
1992 Lincoln Mark VII LSC/SE (red)
1970 Datsun Pickup
1953 Chevy pickup (converted 4x4)
1988 T-bird Turbo Coupe

Jolo

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Re: Oil Pressure Gauge: 79 TA 400 4 Speed
« Reply #2 on: May 04, 2021, 12:40:37 PM »
Thanks I think the best option is to connect a cheap mechanical gauge and see what I get.

Jolo

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Re: Oil Pressure Gauge: 79 TA 400 4 Speed
« Reply #3 on: May 12, 2021, 12:59:01 PM »
Should either a mechanical or an electric oil pressure gauge show pressure while the engine is cranking prior to start?  I am deliberately not starting the car until I see oil pressure during cranking, on the gauges i have installed directly to the engine (I believe the car's in dash electric gauge is bad).  Seems I should see pressure during cranking.  I don't even see oil in the pvc line to the mechanical gauge.  I pulled the distributor and lined up my priming tool to the oil pump drive draft, primed some more, then lined up the oil pump driveshaft to the distributor at 18 degrees btdc.


firebirdparts

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Re: Oil Pressure Gauge: 79 TA 400 4 Speed
« Reply #4 on: May 12, 2021, 02:26:22 PM »
They will, but it takes a little while, say 5 seconds.  The electric gauge has to be powered during cranking (not just running).
« Last Edit: May 12, 2021, 02:32:56 PM by firebirdparts »
I want to be like Paul Kenny when I grow up
Joe Bays
1977 Y82 4-speed (red interior)
1978 Skybird 350
1978 Redbird 305
1979 Redbird 301 4-speed
1992 Lincoln Mark VII LSC/SE (red)
1970 Datsun Pickup
1953 Chevy pickup (converted 4x4)
1988 T-bird Turbo Coupe

Re: Oil Pressure Gauge: 79 TA 400 4 Speed
« Reply #4 on: May 12, 2021, 02:26:22 PM »

Savage Larry

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Re: Oil Pressure Gauge: 79 TA 400 4 Speed
« Reply #5 on: May 12, 2021, 08:07:17 PM »
I would install a handheld mechanical gauge and then run your pump with the priming tool. That should give you a good idea of the kind of pressure your pump will build if you are worried.
Jay
Calgary, AB
1977 4 speed W72

Re: Oil Pressure Gauge: 79 TA 400 4 Speed
« Reply #5 on: May 12, 2021, 08:07:17 PM »
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