ENGINE SHUT-DOWN / FUEL SYSTEM BLEEDING PROCEDURE / FUEL LIFT PUMP WIRING SCHEMATIC /

Tiny
MTRDUDES
  • MEMBER
  • 2002 FORD F-450
  • 7.3L
  • V8
  • TURBO
  • 4WD
  • AUTOMATIC
  • 126,120 MILES
This is a customer's truck; VIN #1FDXF46F52EA48868 and it has a aerial boom mounted on it. The two complaints were 1) the truck would shut off intermittently when the windshield wipers were turned on and 2) the engine just started hesitating and sputtering when started cold but smoothed out after a minute or so; the truck was being used daily until I worked on it Thursday the 11th. I checked it and found engine shut-down only occurred when the washers were engaged and then not every single time but most of the time. I checked the fuses and relays along with the multifunction switch & harnesses and believe it is in the switch but don't have the adequate wiring schematic to confirm that; I also experienced no problem with the engine hesitating/sputtering when I first cranked it cold, even going so far as to give it a 15 minute road test where it performed fine. The owner then asked me to service the engine so I performed that before going back to the washer/performance issues. I changed the engine oil and oil/fuel/air filters along with filling the fuel bowl with fuel, filled the engine with 5/40W synthetic Rotella then started the engine to make sure there were no leaks. I ran it a couple minutes then shut off to check the oil level; realizing I didn't check the transmission fluid I started the engine again only to experience the sputtering the driver had described earlier. I shut the engine off then attempted to restart, this time it cranked over and acted like it would catch and start but never did. I cycled the ignition key a few times per the owners manual for bleeding purposes then attempted to start again but it did the same thing. I checked the fuel filter bowl and found very little fuel in it so I filled it again, installed the filter and tried starting but the same result. I checked the fuel bowl and found it almost empty again so I turned the ignition key to start with the cap off to check for fuel delivery but no fuel pressure at all. I checked all fuses and relays for the fuel pump and injector driver module, all good. I went underneath and checked for power at the lift pump and had no power with the ignition key on but didn't have a schematic for the wiring harness to check for the break in power. I'd like to get schematics to check the w/s washer / multifunction switch circuits as well as the lift pump circuit and would also appreciate any further information you could give me regarding the above details, thanks.
Friday, September 12th, 2014 AT 8:02 AM

7 Replies

Tiny
HMAC300
  • MECHANIC
  • 48,600 POSTS
I am not a diesel guy so ican't answer question about the diesel but this may all be related. There is a ground at left rear of engine compartment that pcm and wiper motor ground to, so im kinda thinking that this may not be grounding good there or the wire from battery ground to body is not connected or broken corroded etc. Causing your problem or part of it anyhow. Try it an dget back to me because i'll have it given to someone else who ismore familiar with diesels to see if they can help.
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Friday, September 12th, 2014 AT 4:29 PM
Tiny
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I won't see the truck again until Monday so I'll check it and let you know, thanks.
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Friday, September 12th, 2014 AT 5:32 PM
Tiny
HMAC300
  • MECHANIC
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Okwell let me know because I can try to give it to someone who is more diesel oriented
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Saturday, September 13th, 2014 AT 5:36 AM
Tiny
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OK, found that ground you referred to along with 4 others; removed, cleaned and installed all of them. Replaced both batteries because one was weak and both were over 4 years old. Engine started and ran like it had air in the fuel system; it never bled out fully and ended up shutting off. I removed the fuel bowl cap and found the bowl almost out of fuel just like the times before; I refilled the bowl then cranked but never started the engine and now it just cranks over without catching. I rechecked all the fuses and relays (owner replaced fuel relay under hood but made no difference). I worked on it Thursday last; on Friday one of the employees replaced the fuel relay and it cranked and started so he drove it just to check; it got down the road about 4 miles then he turned around because he said it started running rough and then shut down so they towed it back to their shop. It seems like if you let it set for 3-4 or longer hours it' cranks and runs but only for a few minutes before it looses prime and shuts down again. Out of options and really need some guidance, thanks.
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Monday, September 15th, 2014 AT 10:18 AM
Tiny
HMAC300
  • MECHANIC
  • 48,600 POSTS
Like I said before I am not a diesel guy but check fuel pressure it should be 40-60 psi with engine running. That is primary fuel line pressure it kind of sounds like a bad pump to me. Also lift pump we have no diagram for that other than it would have a power wire most likely connected to battery I think or maybe fuse box. I'm sure if you look online you can find it from lift manufacturer. I'lll also give this to see if we have someone who is more in tune with diesels.
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Monday, September 15th, 2014 AT 12:15 PM
Tiny
MTRDUDES
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  • 36 POSTS
Engine cranks but won't start, only occasionally does it start but then for only a few seconds or minute before it loses fuel prime then shuts off so I can't check fuel pressure. Haven't been able to get any schematics regarding the lift pump wiring circuit; there is no power to the lift pump with key on and have twice checked all fuses and relays, all good. At complete loss as to why this has happened and will be glad to talk with anyone that can give me a more complete picture, thanks for the help.
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Tuesday, September 16th, 2014 AT 1:24 AM
Tiny
HMAC300
  • MECHANIC
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Ok im sending three pics as the whole system is to much to copy but these are the important ones. Power is sent to fp relay via fuse box then to fuse 40 then to relay also fuse 23 in centnral junction box. From relay to inertia switch to pump. All locations are given in pics however they are small. Dk grn yellow to inertia switch then red to pump. Hope this helps. Ihave also turned this back in to see if someone else can help with this.
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Tuesday, September 16th, 2014 AT 5:55 AM

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