oil pressure lost /engine cuts off

G

ghostryder

Registered User
have a 90 5 spd has a brand new engine, oil pump all the sensors are new. car runs good after driving around for about an hour or so the oil pointer drops down to the L position then the cart shuts off. it will start back up but the oil pointer goes right back down to the L position if I keep my foot on the accelerator the gauge stays in the middle but soon as I let off it drops down and car shuts off. it will idle normally for a while then the gauge drops and car shuts off. if I look thru the oil filler cap I can see the oil circulating and the oil filter is hot with circulating oil.

I've checked many many old post on low oil pressure and none address the issue I am having. does anyone have any recommendations on where to start troubleshooting
 
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With that new engine, were any of the accy. brackets painted? Were all the grounds replaced?

The stock oil pressure gauge is basically an idiot light...it won't follow actual pressure swings.
 
oil pressure gauge

I had a similar problem with the oil pressure (switch that Ford passed off as a) gauge. Pressure gauge was fine until car warmed up and then the needle would drop (unless RPMs were high) and the 'CHECK GAUGES' light would illuminate. I cleaned the terminals but the problem didn't go away until I replaced the sending unit. However, the car did NOT quit on me when this happened, so I can't say this would fix your problem. I'd start with checking the grounding. I've had problems with starters to crankshaft position sensors because of a bad ground.

Horn
 
I think you are incorrectly associating the low oil pressure with engine stalling. More likely it's a vacuum leak that is small enough that it doesn't impact idle until engine is warmed up. Since the gauge isn't really a gauge and anything over 7 psi will usually keep the needle in the safe range, the idle falling off because of the vacuum leak could be causing enough of a voltage drop to make the gauge read low. A loose wire connection at the sender will also cause the gauge to read low.

David
 
Was the engine installed by you or others? If by others, it's possible (though an outside chance) that they could have installed an oil pressure switch ignition cutout to protect themselves on warranty claims. Some OEMS have done this on occasion. Just a weird thought, but it's possible.
 
I sanded all the areas that have grounding cables and made sure everthing was tight. the brackets are painted but were the DIS goes is not. I will clean replace the oil pressure switch. going to have it smoke tested on Friday.
 
S_Mazza said:
Was the engine installed by you or others? If by others, it's possible (though an outside chance) that they could have installed an oil pressure switch ignition cutout to protect themselves on warranty claims. Some OEMS have done this on occasion. Just a weird thought, but it's possible.
Click to expand...
I installed the engine myself
 
What is your vacume gauge doing during all this? and you installed the sending unit?
 
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