Cyberfarmer Posted July 15, 2009 Share Posted July 15, 2009 Hi! I am currently diagnosing a P38 4.6HSE (coil spring converted) and my problems right now are the ff: 1. When engine started, it will idle for a few moments and would die down. 2. It would only start again if you only take off one of any sensor plugs. 3. When revving engine it would go down first to 200 rpm then go up harshly and when foot is released it would seem to die down. 4. On ROVACOM diagnostics, it couldn't read any fault codes, readings are within parameter and still dies down. Vehicle is in good operating condition prior to this dying problem. I tried replacing all possible sensors but to no avail. Spark plugs are new and cables. Please help. Thanks. Quote Link to comment Share on other sites More sharing options...
vougese39 Posted July 22, 2009 Share Posted July 22, 2009 Hi! I am currently diagnosing a P38 4.6HSE (coil spring converted) and my problems right now are the ff:1. When engine started, it will idle for a few moments and would die down. 2. It would only start again if you only take off one of any sensor plugs. 3. When revving engine it would go down first to 200 rpm then go up harshly and when foot is released it would seem to die down. 4. On ROVACOM diagnostics, it couldn't read any fault codes, readings are within parameter and still dies down. Vehicle is in good operating condition prior to this dying problem. I tried replacing all possible sensors but to no avail. Spark plugs are new and cables. Please help. Thanks. could be afuel pressure fault or injector or fuel filter fauls if youtry to rev does it cut out quicker? Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted July 23, 2009 Author Share Posted July 23, 2009 could be afuel pressure fault or injector or fuel filter faulsif youtry to rev does it cut out quicker? Sometimes yes. When I try to rev the engine up to 2500 rpm and decelarates the engine would almost cut out up to 300rpm or die but it wouldn't reach 700rpm at idle. The tech reading doesn't find any sensor fault. Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted July 23, 2009 Author Share Posted July 23, 2009 I replaced all engine harness and sensors. It still dies down. Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted July 23, 2009 Share Posted July 23, 2009 The lack of fault code and the fact that you have changed most of the electrical side lead me to suspect fuel pressure too, and a pressure check may show a problem, but not necessarily if that problem is an inability to flow sufficiently. I think that my next move would be to check all of the fuel supply and return pipework for damage or kinks and replace the fuel filter - after that if it's still the same I would be looking at the fuel pressure regulator. Sorry I can't be definitive, but I have never experienced the problems you describe. Hopefully somebody will be along soon who recognises this problem.. Roger Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted July 23, 2009 Author Share Posted July 23, 2009 I now installed a new pump, new fuel filter, fuse box, ecu, afm.......and its still the same!!!!! no fault codes!!!! its crazy!!! Quote Link to comment Share on other sites More sharing options...
vougese39 Posted July 23, 2009 Share Posted July 23, 2009 I now installed a new pump, new fuel filter, fuse box, ecu, afm.......and its still the same!!!!! no fault codes!!!! its crazy!!! have you had the injectors tested? Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted July 24, 2009 Author Share Posted July 24, 2009 have you had the injectors tested? Not yet but I presume injectors are good since I just had them replaced last 10,000 kms..... Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted July 24, 2009 Author Share Posted July 24, 2009 We just finished opening the valve cover and front cover. Everything seems normal except for a 5/16 slack on the timing chain. Quote Link to comment Share on other sites More sharing options...
vougese39 Posted July 24, 2009 Share Posted July 24, 2009 how many miles has it done? Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted July 24, 2009 Author Share Posted July 24, 2009 how many miles has it done? only 83,000 kms Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted July 26, 2009 Share Posted July 26, 2009 You say you have replace fuel pump and filter, how about fuel pressure regulator? Checked for fuel pressure? Changed air filter/tried with it off? Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted July 27, 2009 Author Share Posted July 27, 2009 You say you have replace fuel pump and filter, how about fuel pressure regulator? Checked for fuel pressure? Changed air filter/tried with it off? Yes i did replace fuel pressure regulator. Fuel pressure is within normal range. I haven't tried starting it without filter though. I let you know later. Thanks Quote Link to comment Share on other sites More sharing options...
Cyberfarmer Posted August 1, 2009 Author Share Posted August 1, 2009 I found it!!! It was a faulty new BRITPART fuel pump!!! The pump was fouling after a few minutes and then would fire up again. Thanks to all those who helped. Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted August 1, 2009 Share Posted August 1, 2009 Result! Thanks for letting us know what the final diagnosis was Quote Link to comment Share on other sites More sharing options...
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