intermittent no start
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intermittent no start
Started my 2005 f250 powerstroke, idle about 15 min and died like I turned key off. Hooked up scan guage had no flp, fmp or syc ipr and icp was good. Checked ficm relay and fuses and all checked good. Next morning went out and it started flp, fmp, sycall good. Idled about 1 hr and died again same bad readings. Messed with relays and wiring to ficm, it started and died after 2 min. No start again, next morning still no flp, fmp. Went out again in afternoon and everything was good again, I did nothing to it from am to pm, was loading my pistol they shoot horses don't they. I have new batterys, I changed the ficm power card last summer for low fmp. When it is running everything looks and sounds good no miss.
Fleet Mechanic
Joined: Jun 2006
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I believe you have an intermittent 70 amp FICM power relay and it is not interchangeable with any other relay. With a little patience, you can take the relay apart and check for burnt and or pitted contacts. The contacts are usually pitted to the point that they cannot be reconditioned. If you have a lot of miles on your ride, it is probably time for a new relay. If that fixes it, take the bad relay apart and you will see what I mean. Ask me how I know.
Ed
Ed
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Joined: Jan 2017
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From: Central Illinois
Always begin with the simple basics. Load test batteries, check all connections, etc. Once you verify that everything is up to par then move to further more in depth diagnosis.
These trucks are extremely picky on having healthy batteries.
These trucks are extremely picky on having healthy batteries.
Fleet Owner
Joined: Nov 2003
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If all looks good, I would begin to suspect the FICM (logic side).
Get on Ed's web site (FICMrepair.com) for some simple troubleshooting techniques. If it is your FICM, have Ed rebuild it.
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Fleet Mechanic
Joined: Jun 2006
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Are your driver side battery connections clean and tight? When you say EVERYTHING goes to 0 is that both FLP and FMP voltage? You need FLP to turn on FMP and when that happens the correct FMP happens, so I don't think it is the FICM. Do you have power to your accessories? All of the power required to start the truck comes from the driver side battery connection. The GPs and starter are powered by the passenger side battery connection. Again, if they are not clean and tight, weird S**T happens.
Ed
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Fleet Mechanic
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From: Coal Valley, Illinois
I had an intermittent no start issue that probably different than what you are dealing with. Have BPD FICM and a lot of other upgrades. Took it to a shop specializing in Ford Diesels. The guy is very good and knowledgable. Anyway after much testing and dyno tested with all sorts of sensors (had a new turbo and other stuff installed at the same time). The best guess was a problem in the wiring harness. Ended up replacing, cost a fortune but problem fixed. Highly unlikely that's your issue but those harnesses are tightly fit and wiring can get damaged over time as can any wiring or connections.
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Thanks I have new battery's and the terminals are good. When it dies flp, fmp, syc and fvp go to 0. Everything else is good all assy power and ign powers. I pulled the 15 amp fuse and had power there thru the ficm relay. The wiring all looks good and the shake test was no help. By the time I was able to get to remove ficm to check power to the connector I had all the powers back on my scan guage. The way it comes and goes sometimes without doing anything but open and close door I am thinking about trying another ficm.
Senior User
Joined: Jan 2017
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From: Central Illinois
If ficm checks good a bad crank or cam sensors can cause ficm sync to drop out. Cam sensor is more common than crank. Bad crank will be easier to see by watching rpm. I'd check out the wiring were the cam comes up into the loom. About the 2 o'clock position looking at the top of the fuel bowl under the air filter to turbo pipe is were the cam wires come up into the loom.
Fleet Owner
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Glad it resolved your issue, sorta looked like a FICM issue!
As you can see, it isn't always easy to diagnose though. That is why I have a (several, lol) spares.
As you can see, it isn't always easy to diagnose though. That is why I have a (several, lol) spares.
Fleet Mechanic
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Thanks for sharing the fix. A lot of people on this sight ask for advice and we, who provide advice, never hear what the fix is.
Ed
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Someone drops a bomb after signing up, then posts 1 or 2, and either gets it fixed here or elsewhere or gives up.....never to be heard from again with no results posted. I often wonder how many dead accounts there are lurking here.
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