Wonky stock early NA oil pressure reading?
#27
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I can get the gage to do the same thing pushing in the clutch and applying a hard jab to the throttle. Don't think that would be knock in that instance. Seems to be more rpm and accelerating rpm related than load.
Im stumped.
Bob
#29
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When I turn the key on I’ve got ~30 Psi reading on the gage before I hit the start button. And it will hold it for a minute or so before it discharges down all the way.
Bob
#32
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Well yesterday was my first track day since motor rebuild, Accusump install and Breather/crankcase evac system install. Quite a bit of testing and tuning on the road with the only apparent issue being the oil pressure gage.
The breather system sucked out mass quantities of oil after hard left hand turns and created great smoke screens, the Accusump seems like it quit working, and the oil pressure gage is still wonky.
I diagnosed the breather system was sucking oil out through my slash in the exhaust when the catch can got a big slug of liquid oil in it. The pressure gage on the Accusump itself just stays at 80psi and it doesn’t appear the valve is opening. The pan became over filled but draning it down didn’t help the breather issues.
On the plus side the car seemed to run really well even with the occasional smoke screens it was leaving and I was the fastest car at the SCCA time trial by like 5 seconds. I don’t believe the oil pressure sensor is reading knock. The plugs looked perfect after pulling them out after the first big oil smoke episode. The oil was not going through the combustion chamber.
Bob
The breather system sucked out mass quantities of oil after hard left hand turns and created great smoke screens, the Accusump seems like it quit working, and the oil pressure gage is still wonky.
I diagnosed the breather system was sucking oil out through my slash in the exhaust when the catch can got a big slug of liquid oil in it. The pressure gage on the Accusump itself just stays at 80psi and it doesn’t appear the valve is opening. The pan became over filled but draning it down didn’t help the breather issues.
On the plus side the car seemed to run really well even with the occasional smoke screens it was leaving and I was the fastest car at the SCCA time trial by like 5 seconds. I don’t believe the oil pressure sensor is reading knock. The plugs looked perfect after pulling them out after the first big oil smoke episode. The oil was not going through the combustion chamber.
Bob
#33
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Did you leave a breather port on the passenger side of the valve cover? I put one on that side and on left corners I dumped oil by the quart, and I'm not exaggerating. I now run only one on the driver's side and get a minuscule amount of oil through the line.
#34
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I also have a drain back to the very bottom of the pan that may be the problem. But if the oil doesn't drain back somehow the slash cut will suck it all out the tailpipe when it starts to fill up.
I tried loosening the fitting to the hose going to the slash cut thinking it would pull less vacuumed and the result was oil spewing in the engine compartment.
Bob
#36
I decided to put my timing map back to the way it was on the dyno and use my electronic detcans to see if I could hear any det. I was surprised at how obvious the detonation sounds. Unfortunately I wasn't able to look at my oil pressure gauge at the time since I was trying to get a quick pull in traffic. I removed a degree of timing in the suspect area, and I'll give it another try. Once all is tuned, I'll see if the OP gauge is still bouncing around.
#37
Another update: I did some "listening " this morning on the way into work, and was able to watch my OP gauge. The knock I hear with the detcans is directly related to my OP gauge flickering. I listened to the car without the detcans, but couldn't hear any audible problem. Again, it is very obvious with the detcans.
#38
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Another update: I did some "listening " this morning on the way into work, and was able to watch my OP gauge. The knock I hear with the detcans is directly related to my OP gauge flickering. I listened to the car without the detcans, but couldn't hear any audible problem. Again, it is very obvious with the detcans.
Bob
#39
No knock sensor, just listening with electonic det cans. I haven't tuned out all of the knock yet, but I'm working on it. Once I do, I'll really flog it and see if the gauge still moves. It seems to be in my 230kpa row. I was initially running 17*, I stepped down to 14*, and I'll see how that works this afternoon.