Electrical Problem Oil warning light, speed o and engine limiter all short same time

[Bob]

I have a 91 NSX SC 1000,000
The warning light for oil pressure[/I] (white blinking light on left dash), the speedometer and the rev limiter on engine revs stops at 7200 rpm. When light is off speed o working engine will reach 8200 rpm . All three short at same time and come back at same time when it wants and works great when it wants .I knew i had problem when i changed oil sending unit in engine block and it still did it lighting up.
Then the speed o would not work at same time at light comes on as well as engine revs not being able to pass 7200 rpm before cutting out. When light is off n speed o working car will go to 8200 rpm I need help My Acura guy has no clue lol All three go out and come back and work properly at the same time it does it randomly but very often. What are they hooked up to ???

 

[Briank]

The light works off a pressure switch on the oil filter pedestal, check for loose connections or pinched wire, it likes to get under the head cover.

 

[pgilliam1]

You changed the oil sending unit in the transmission?

There are 2 oil pressure units on your car. As Brian said, the one on the oil filter pedestal which lights the idiot light and another unit that works the oil pressure guage on the dashboard which is located on the engine block on the drivers side front just below the spool valve.

If the engine thinks it is being oil starved I think it will run in limp mode which may cause your low RPM problem (not 100% sure on that, but I think I read that here sometime ago).

 

[Bob]

ok thanksI wonder why all three problem come and go at same time white oil warning light. speedometer stops working and the engine limiter stops at 7200 rpm. They all do it together work n not work when it feels like it. When light is off and speedometer working the car rev to 8200 like it should ????
Seems funny that they all do it same time