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California98Civic · 03-07-2015, 07:36 PM

Undoubtedly, the fuel pressure regulator change fixed the problem [EDIT: fixed it for a little while]. For two weeks almost everything has been normal, but slightly longer starter motor turning before she fires-up. And I think I was in a little denial, because all the previous issues that started this thread just came back this afternoon with a vengeance. Suddenly, the car sputters, the short term fuel trim leans-out steadily during a pulse at 75-80% load. It will get as lean as -28% short term fuel trim in a single pulse. Does that every time, over and over. Go into neutral and a new symptom is that it will sometimes stall. Stalling events sometimes are preceded by an idle speed that is unsteady: rpms 180 and then 500 and then 900 and then 700, 900, 800, and then stall or... you get the idea. Sometimes it does that and then keep running. The one thing that never returned quite to normal after replacing the fuel pressure regulator was the starting cycle, which required slightly longer cranking almost every time. Pre-priming the fuel pressure with the key only sometimes seemed to solve the problem. I have been meaning to look into it, but there are always a few things with this car, and I gotta live and work too. Haha! Back to testing...

Any ideas?

03-07-2015, 07:36 PM	#17 (permalink)
California98Civic Cyborg ECU Join Date: Mar 2011 Location: Coastal Southern California Posts: 6,299 Black and Green - '98 Honda Civic DX Coupe Team Honda 90 day: 66.42 mpg (US) Black and Red - '00 Nashbar Custom built eBike 90 day: 3671.43 mpg (US) Thanks: 2,373 Thanked 2,172 Times in 1,469 Posts	Undoubtedly, the fuel pressure regulator change fixed the problem [EDIT: fixed it for a little while]. For two weeks almost everything has been normal, but slightly longer starter motor turning before she fires-up. And I think I was in a little denial, because all the previous issues that started this thread just came back this afternoon with a vengeance. Suddenly, the car sputters, the short term fuel trim leans-out steadily during a pulse at 75-80% load. It will get as lean as -28% short term fuel trim in a single pulse. Does that every time, over and over. Go into neutral and a new symptom is that it will sometimes stall. Stalling events sometimes are preceded by an idle speed that is unsteady: rpms 180 and then 500 and then 900 and then 700, 900, 800, and then stall or... you get the idea. Sometimes it does that and then keep running. The one thing that never returned quite to normal after replacing the fuel pressure regulator was the starting cycle, which required slightly longer cranking almost every time. Pre-priming the fuel pressure with the key only sometimes seemed to solve the problem. I have been meaning to look into it, but there are always a few things with this car, and I gotta live and work too. Haha! Back to testing... Any ideas? __________________ See my car's mod & maintenance thread and my electric bicycle's thread for ongoing projects. I will rebuild Black and Green over decades as parts die, until it becomes a different car of roughly the same shape and color. My minimum fuel economy goal is 55 mpg while averaging posted speed limits. I generally top 60 mpg. See also my Honda manual transmission specs thread. Last edited by California98Civic; 03-07-2015 at 08:13 PM..