06 f350 wont start shows 0rpm while turning over
 

my truck is an 06 F350 6.0 automatic 4 door 4x4 209k miles with egr delete bullet proof diesel engine oil cooler bullydog PMT (usually set to extreme) my problem is intermittent and dosent seem to follow any hot/cold pattern sometimes it starts and runs like a new truck leading me to think its electrical rather than mechanical but when it decides to act up it will show zero rpm while the engine is turning over strong i have been told it has to read 100 rpm minimum to fire the injectors and i am sure it is turning atleast that then if it does start it will run ok for a bit then start to surge especially while idling in gear with the break on then other times it will quickly surge then die occasionally when i try to retrieve trouble codes on my PMT it has trouble communicating with the truck and most often reads a camshaft sensor code after trouble it also looses the rpm reading on the PMT ( but none of the other readings) if i press the break pedal more than half way dosent matter if moving or not i have replaced the ICP sensor and pigtail the cam and crank sensors tested the FICM voltage tried wiggling wiring harnesses and connectors while it was running right trying to duplicate/locate the issue with no success this is my daily driver/work truck that i tow a 26' trailer regularly with any help would be greatly appreciated could it be in the PCM or computer side of the FICM ?:argh:

the only code it has set is P0335 crankshaft position sensor circuit A thursday i almost had to have it towed home and it wouldnt restart when i got it here friday i tried it and it started but quickly died today i went out to try and see if i could figure it out and it fired up i drove it to the store for a little fuel and back probably 10 miles with no issues then i let it idle for about 20 minutes both with it in and out of gear still no issues but i never know when this thing is going to leave me stranded

i have been driving my other truck so i went out and cranked the f350 today it started fine a little sluggish because of batteries no being charged for a while but still cranked i let it sit and idle while i was working around the house just to charge the batteries up and somewhere around 170 degrees 15-20 minutes of idling it died when i noticed it died i went and tried to crank it and it was back to turning over strong but showing no RPMs on the tach surely someone has had a similar problem and can shed some light on this for me

I had a customers truck come In like that and it was a sprag in the tranny that was broke and would stall the truck after start up.

It's not uncommon to get a bad sensor, maybe you can test the sensor ? I would disconnect the bully dog and see if it still acts up.

sorry it took me a while to get back I have tried programming the truck back to stock and disconnecting the bullydog with no change in the symptoms i have noticed since i have not been driving it that it only takes about a week and a half for the batteries to get weak could a bad battery be causing any or all of this ? i wouldnt have thought so but i see on other threads that these trucks seem to be very sensitive to batteries oil and just about everything else

i am wondering if i should just go ahead and buy a used motor and have installed but i am worried if it is something in the electronics all i will accomplish is having a lower mileage motor with the same issues any advice on that front ?

I would test and find problem. If you read past posts there are tests for every problem a 6.0 can have. Patience and perseverance are rewarded with a sweet running truck again!

i hope so i keep reading and working on it every chance i get which isnt often on the brite side at this rate at some point i will have a lifetime warranty f350 because i will have replaced everything lol

Get a scan guage 2 or some way to figure out without buying parts. It gets really expensive if u parts bomb it.