Ozzie831 Posted June 22, 2015 Share Posted June 22, 2015 Hey how's it going? Ive been dealing with my 77 280z turbo project these past few years and Im having a serious problem with either pump cavitation or vapor lock. I dont care what you call it, it's getting really annoying. The car will start up and drive just fine to my destination; however, if it sits more than 10 min I have to sit for several hours just to get the afr back to a safe driving range range. I only work 5 miles away and I usually have to wait my entire 8 hour shift for it to not be running super lean. Several times I have tried to leave and go on lunch but my AFR is at 17+ so I was stuck till it went down. Ive tried heat shielding everything, tried different pumps (currently with a walbro 255), bigger fuel lines (only the rubber lines, not the hard lines), I have hood vents, Ill even leave my hood open half the time hoping that will help. My normal AFR at idle and cruising is about 13.3, but when this leaning out happens, it get to 15's+. While the car is on, the temp doesnt get above 180. Im assuming its pump cavitation solely based on that Ive noticed my fuel pressure being lower whenever this happens (plus people have said that z's cant get vapor lock). Ive even revved the engine and watched the fuel pressure plummet the higher the RPM's get, plummet as is goes from 32 psi to 0, or pretty darn close. Any advice is extremely appreciated. If there are any questions about specs/parts/anything, please feel free to ask. Austin Quote Link to comment Share on other sites More sharing options...
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