The car run fine until I realized that the Oil Pressure gauge can only go max at 4.5 reading.....cant even go to 5 or 6 so I guess the VTEC cant even be opened,right ?

To comfirm the low reading,I even installed Arospeed oil pressure reader & yes,the readout was same.At max redline it would only hit something like 4.5 only....cant even go near 6 at both gauge at all.

Idling was fine at 2" for both gauge.

So what is the real culprit?Either the sensor sending unit problem or other else that I forgot to think/mention here ?

 

Did you remove the oil pressure sending unit to check the pressure. I'm not familiar with the gauge you mentioned. Check your oil level. Don't redline the motor until you fix the oil pressure, an NSX motor is built by hand, has titanium connecting rods, and will cost a small fortune to replace. The VTEC needs oil pressure, temperature input, throttle position and vehicle speed input to engage. A sending unit is inexpensive and easy to install, replace the sending unit and recheck the pressure.

 

I would do more checking over the car. I looked at a buddy's car and he had a similar problem and the car would not rev past 4500, and all that was, was an injector clip not pushed down all the way on the injector. So my advice to you is don't just look at one thing as the problem.

 

Thanks for the advice.

For your info,the meaning of my earlier 4.5 reading was not the RPM but oil press. gauge.The RPM was fine but as I running-in the engine,I do not push the engine very hard either.I was driving it slowly around 60-65 mph only.

The only thing that bother me is the idle oil press. reading for both oil pressure reader(Arospeed ) in engine bay & the one in tach was OK & same at 2 kg/fm.....but as the RPM climbed,the oil press. gauge only register the readout at max 4.5 or almost 5 kg/fm.Cant go even further than that.

So like you all said here,I would try to clean the press. sender unit first then we'll see what happen next....