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On Sat, 12 Feb 2005 00:31:13 GMT, aarcuda69062
> wrote: >In article >, > Lawrence Glickman > wrote: > > >> > All of these parts are new or re-built. >> >> So what is left over that could be causing his symptom of loss of ALL >> fuel pressure on occasion? > >It could be any of the parts he's already replaced. >The fuel pressure bleeding off at rest can only occur in three >places; >1) Injector (CPI) assembly >2) Fuel pump check valve >3) External fuel line between #s 1 and 2 > >It's not hard to isolate sections of the fuel system to determine >where the leak off is. > >> What would you want to look at next as a probable cause of his >> difficulties? > >If it is fuel starvation or over fueling, it will show up on the >O2 sensor voltage and/or the fuel trim numbers viewed on a scan >tool, I mentioned this to him in a post a while back at the >beginning. He procured a scan tool but went no further with it. >He could have posted the scan data here and myself and a number >of others could have given out opinions of what was there. OK. Myself, I've recorded what should be "normal" numbers for my own engine using a data logger and storing the file(s) on my hard drive for future reference. I've also used my Scantool to record what parameters that reveals: e.g. long term fuel trim bank 1 % = 5.5, 4.7, 1.6, 2.3 short term fuel trim bank 1 %= 0.00, -2.3, 1.63, 3.9 long term fuel trim bank 2 %= 3.1, 3.9, 7.0, 7.8, 7.0, 7.8, 3.9 short term fuel trim bank 2 %= 2.3, 2.1, 0, -.08, -2.3, -3.1 and I am lead to believe, from my readings, that it is perfectly NORMAL on my engine for bank 1 to be quite different from bank 2, although I can't put my finger on the source of that information at this moment. Now goody for me, I can program my data logger to record all of the above values in a continuous stream if so desired, so if I see any MARKED deviation from my baseline reading, I've got a "clue." There are many many other parameters I've recorded for baseline purposes, too many to list here. Point is, I would have reference values to consult. Maybe this is asking too much for anybody to do. >He did mention in one post that his running fuel pressure dropped >to 50 psi, this is 4 psi below the absolute minimum required to >open the poppet nozzles in his CPI system ( pressure >differential) > >He'd be best off with a scan tool with recording capability, that >way he can trigger a recording on a test drive at the moment the >problem occurs, and then review the movie from the trigger point >for anything unusual. Wouldn't he get what's called Freeze Frame? IOW, my data logger has the ability to show all engine parameters it is capable of reading at the moment a malfunction occurs. I've never had the pleasure of seeing this happen, so I can't be more specific, IOW, I can't give you the parameters delivered because it hasn't happened to me =yet=. But if and when it does, I may post for General Information purposes. >It's also entirely possible that it isn't a fuel problem. Could be electrical. Intermittent loss of power to fuel pump, etc. But I'm wondering if that wouldn't throw a DTC. Again, I've never experienced ( on this car ) a malfunction so I can't be more specific. Lg |
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