mjb.thomassen
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The idle fuel rail pressure Will be measured after rebuilding the injector together with Electric measurements
P38 4.6 goes to 1800 rpm after starting
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Remember to get some RTV sealant for the plenum.
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Is it possible a temperature sensor is giving a duff value and it is throwing in extra fuel to compensate?
IIRC Rave recommends loctite 577
Before you embark on all the other suggestions try resetting adaptive values...I had exactly this issue on a 4.0 v8 and it cleared after resetting adaptive values. In particular the ecm stores a reference voltage for idle of about 0.58v. That can get corrupted in the memory, and then the whole mix and idle speed gets messed up...either it wont start at all, or it starts and goes to a high idle. Even if you dont have nano there is (or was) a v8 phone app that can do it via Bluetooth Obd II
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I tried that app just to see. Didn’t work
mjb.thomassen
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Had the injectors out to clean, with the fuel rail out I checked the fuelpressure, it was only 2.3 bar even not enough to get a good injector image.So I ll have to find that problem first like leaking injector, bad fuel filter, bad pump
mjb.thomassen
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I Just see on youtube that the pressure is 30 to 35 psi so I have a correct pressure
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What was the condition of the seal on the plenum chamber ?
mjb.thomassen
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Almost nothing left
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So after you've done all the injector cleaning, during re-assembly seal it properly, and then see if the high idle is solved !!
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Hmmmm....
mjb.thomassen
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After checking all the injectors on the rail for the third time suddenly one injector was leaking and the pressure went down when closing . This only at 2 to 2.3 bar. At lower pressure no problem. I ordered a New one, so I hope problem is solved.
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That explains the extra fuel. Well done.
