DieselD Posted August 13, 2010 Share Posted August 13, 2010 Yep sounds like a 6.0 huh? Well this one is much more of a headache. Im on hold with hotline as we speak so figured I would post this question here. 2008 6.4, 71k miles. 3729hrs. Its an electrical boom truck which is a huge pita to get the cab up! First I got this in a couple weeks ago for a knocking/popping noise. Of course its a broken rocker arm and lifter. yank the cab which SUCKED! 5million wires and no bulkhead connector in sight! anyway got that all fixed and up and running. Ran great up until the time I went to move it out of my bay and it would not start. P0001 Fuel Volume regulator control circuit open. Funny thing the engine cools down and it will restart without issue. After messing with it I could isolate it to running about 45mins to 1hr outside(temps around 105-110*) with the hood shut. First it starts to run erratic and then will die. Will not restart for about 15-20min after the engine cools a bit and it will fire right up. If trying to bring this in the shop which is about 85 degrees it drops my diag time down to about 10mins before it fixes itself. Followed the pinpoint test. No shorted wiring or any of that bs. led to a pump replacement and hotline agreed. Now after lots of headaches going back into this trud for the second time The pump didnt fix crap. I also changed the pump gasket and checked the jumper harness. Same problem remains without change. Hotline is stumped and so am I. Anyone run into a similar issue? Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted August 14, 2010 Share Posted August 14, 2010 I'd suggest doing a voltage drop on the VCV circuit. If there is a weak connection in the circuit it will likely show up even while the motor is running. You're comfortable with this test, right? If not, let us know and we'll walk you through it. Accessing the connectors might be a bitch but it's a simple circuit- B+ on one side and return to the PCM. Power shows joined to the 4 way interconnect for the PCV and VCV so it's likely after that. Good Luck! Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted August 14, 2010 Share Posted August 14, 2010 I had some early run-ins with this very situation before the HPOP gasket wiring concern was known. I learned a lot - especially having a Navistar Field Engineer assisting with one truck. knowing the havoc the HPOP harness can cause, an electrical short to ground CAN affect everything on circuit CBB12 but what we rarely ever see is something else on that circuit causing issues. One of my experiences with this circuit involved fuse F74 at the BJB. The PCP and the VCV are at the end of the circuit, low current conditions are likely to affect them first. But this is not to omit the idea that any of the other output devices on that circuit can't be pulling down the current. look at cell 26-8 in the EVTM. You will find that Fuse F74/circuit CBB12 supplies voltage to: [*]Volume Control Valve [*]Pressure Control Valve [*]Electric Fan Clutch [*]EGR Throttle Plate Valve [*]Turbocharger Actuator [*]Glow Plug Control Module [*]MAF Sensor Performing a voltage drop as Bruce mentioned will expose a problem here, disconnecting all suspect components one at a time might reveal the cause and don't forget to give fuse F74 a wiggle and visual inspection. My first run-in with a 6.4L was similar to yours in that the truck had to get warmed up and driven for a few minutes before it acted up. This truck would have erratic idle speed, lack of power, stalling and hard starting when it was acting up. After chasing my tail with TWO HPOP's (thanx to the Hot Line) I ended up replacing the PCM... like the service manual instructed me to do. Good luck my friend! Quote Link to comment Share on other sites More sharing options...
DieselD Posted August 14, 2010 Author Share Posted August 14, 2010 Yeah bruce the voltage drop has crossed my mind however this thing has to be smoking hot to act up so doing anything under the hood is a huge bitch with it this hot. I have already gone home with burnt hands from this POS. Of course the 4pin connector is 2inches away from a 5 thousand degree turbo so doing anything with that is almost impossible. This gives me some ideas keith and bruce. Ill work on it some today and monday. Thinking about taking the PCM out and baking the bitch to see if I can recreate the concern to check that off the list. Quote Link to comment Share on other sites More sharing options...
Aaron Posted August 14, 2010 Share Posted August 14, 2010 Bunch of rags soaked in diesel fuel near that turbocharger should fix the problem Could it also be a high-resistance issue in the solenoid itself, only manifesting itself when the heat is present? Kinda like a shitty ignition coil? Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted August 18, 2010 Share Posted August 18, 2010 Would it be possible to install your leads before warming it up. Than you could just take the readings when it is flaming hot. Instead of trying to hook everything up when its hot. Quote Link to comment Share on other sites More sharing options...
DieselD Posted August 18, 2010 Author Share Posted August 18, 2010 Figured it out...Pin 24 on the pcm was tweeked so it was not going into the female section of the pin on the connector but hitting just above it. Only one pin and only that circuit. What are the chances?! Who knows how that managed to get that way. I did have that connector unplugged for the cab removal as I do on countless others. I remember no issues going back in. Lucky me I guess! Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted August 18, 2010 Share Posted August 18, 2010 Glad to hear you found it and thank you for reporting back with your findings! Quote Link to comment Share on other sites More sharing options...
DieselD Posted August 19, 2010 Author Share Posted August 19, 2010 No problem on reporting back, hope to save someone else the frustration I had to endure! Quote Link to comment Share on other sites More sharing options...
STROKER_T Posted September 24, 2010 Share Posted September 24, 2010 got a no start here with p179a,p0101,p0003,and sure enough fuse 74 blows,disconnected jumper harness and fuse doesn't blow...guessing the hpop harness is shorted to ground,so the cab is coming off... With the harness causing issues,should i replace the pump also or just the harness and hope thats the ticket... '08 F350 with 57,000 miles Quote Link to comment Share on other sites More sharing options...
dpurvis Posted September 24, 2010 Share Posted September 24, 2010 once you get in there if you can verify the harness shorted i suppose you could just replace it. i'm sure thats what ford would say, but if there's any dought i'd replace the pump also, always hate to have to do the work all over again. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted September 24, 2010 Share Posted September 24, 2010 Done a few shorts here, and they got the harness/gasket only with no problems. Quote Link to comment Share on other sites More sharing options...
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