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you must have FICM SYNC AS Weell
you can ohm out the cmp and ckp sensor harness you need a scope to fully do it but a dvm would give a pretty good idea didn't you get the pinout for pcm PCM PLUGS PINOUT https://www.ford-trucks.com/forums/a...7&d=1338749081 CRANKSHAFT SENSOR REMOVAL PDF https://www.ford-trucks.com/forums/a...6&d=1350773254 -------------------------------------------------------------------- CMP/CKP WIRE DIAGRAM PDF https://www.ford-trucks.com/forums/a...7&d=1350773292 --------------------------------------------------------------------------- CRANKSHAFT SENSOR TROUBLESHOOT PDF https://www.ford-trucks.com/forums/a...5&d=1350773220 -------------------------------------------------------------------------------- CAMSHAFT SENSOR TROUBLESHOOT PDF https://www.ford-trucks.com/forums/a...4&d=1350773182 ----------------------------------------------------------------------------------- |
Tore the harness apart from the cam sensor clear to PCM. Taped two wires up really nice with 3M tape...then wound the bare wire back around, then wrapped in aluminum foil. I then tapped it all up again and put loom back on and re-taped the exterior of the loom. While I have it apart I once more ohm tested the harness while wiggling it. It passed the test no problem. Visually looked fine too. Put her back together and boom....exact same problem. I will try to beg borrow or steal a meter that will show hertz so I can check it while it's acting up...if it's showing hertz, it's gotta be the PCM??!!
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You Also have CMP/CKP Signal to the FICM
So FICM Sync If Hz is not produced its the Sensor I believe is Bad To my understanding is that the Sensor Produces the Signal on this one vs all the other sensors that just let power thru You Probe the Harness sensor side for crank test |
You should be able to Pull a DTC if its not reading position
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Originally Posted by w69kirkbride
(Post 14254604)
FICM logic power is 11.5 volts and main power is 48 while cranking. Fuel pump does run (its new as well) and have checked pressure at housing and it's within specs. Checked all the chaffing points, and looks good. (THANKS ...good advice and thread)Had it at a buddy's shop last night and he has a new $10,000 snap on scanner. Of course it would only act up once or twice, but when it did: Seems like the PCM had both Cam and Crank signal, but no PCM out to FICM cam crank signal....thus no injector pulse. In the book in clearly shows two pins on the connector going out from PCM to FICM that tell it Crank and SYNC. We also tested and ohm out the harness while wiggling and as was great.
This tells me that the PCM is getting hot and crapping out. You might try: Carry a cooler with ice bags. Next time it gets hot and won't start cool the PCM down. Try not to shock it. You should be able to cool it way down in about 20 min or so. If it starts you have confirmed the faulty component. You can use the same method on the FICM. Cool one component at a time to isolate the problem. . |
Tried a new pcm and icing things down and gave up as nothing worked. Plus back went out on me so I was physically (and mentally at this point) done. Took her to the dealer when they have two great diesel techs that have a very good reputation. Got her back from the dealer 2 weeks later. Definitely not getting sync when acting up hot. They tried replacing cam and crank sensors again, tried a different ECM and FICM, they wiggled tested and ohm tested harness...did all the stuff I did and couldn't solve it either. Basically went through all the tests is the power stroke book. Then they replaced the engine harness. Although no codes (and no interference cam/crank signal codes), it had to be something in the harness right??? The signal was being produced at the sensors but not getting to the ECM. New harness helped but didn't solve it. They could still get it to do it once in a while, instead of a1/2 the time when hot. Then low and behold, the started needed to be replaced. Probably from all the cranking. Bam, problem solved. They showed me the old starter on a bench. It had a small crack in it. How it still worked without breaking all the way is beyond me. Well, the starter was emitting enough radio frequency to interfere with the cam and/or crank sensor signal only when attempting to start it. My harness was partly to blame (it was on the tattered side but it tested ok), but the radio frequency form the busted starter was the main culprit. Or at least so it seems. I guess the RF code would wipe the moment it would start, thus no trouble codes. They bench tested old started and low and behold it emitted a ton of RF. $2900 later, I sure hope I'm done.......
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wow--that's something else--heck 2900 seems cheap as well.
Glad you got it fixed. |
Wow, I don't think anyone would have guessed that. Not only did the starter keep the engine from starting, it kept it from starting only when hot, wow.
Thanks for the follow up. I sure hope that was it and you will have no more problems. . |
Thanks CPB1....I hope so do and so does my credit card!!!! I also hope the few extra cranking RPM's from the new starter wasn't all it needed to see the cam sensor signal and give it sync....although it was putting out the signal right at the sensor....so......
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Ya adding this adventure to the books in case it ever happens to my truck. Dammmmmm well ..... at least you found some light at the end of the tunnel.
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Well, the starter was emitting enough radio frequency to interfere with the cam and/or crank sensor signal only when attempting to start it. My harness was partly to blame (it was on the tattered side but it tested ok), but the radio frequency form the busted starter was the main culprit. Or at least so it seems. I guess the RF code would wipe the moment it would start, thus no trouble codes. They bench tested old started and low and behold it emitted a ton of RF |
Originally Posted by Shaneb75
(Post 14254470)
BTW, I know it doesn't make sense why ether helped it start. The only thing I can thing of is the RPM increased when the ether hit??? :-huh
Originally Posted by BLADE35
(Post 14257956)
Theres More to it then Just having RPM or ICP 500+ psi
I use RPM as one of my Gauges cause it constantly changes and I know once it changes RPM Reading the SGII has updated its numbers and I can know those values are Current You Must Post sensor values for KOEO--Cranking(When it wont start)--Idle--2500rpm ...... RPM Wondering if we can use the RPM # to catch a bad starter (not cranking as fast as its should) & if say 100 or so RPM lower could keep it from starting quickly :-huh Just looking for insight & wondering if know this could've helped the OP or anyone thinking there Starter may be weak :-drink |
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