WILL A BAD CRANK POSITION SENSOR ALSO PREVENT YOUR TRUCK FROM STARTING?

 

yes it will..................check yer codes if it shows then ya have no choice but to replace the sensor

 

hmmnnnnnnn

 

Definitely will cause a no start!

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Usually will throw a CEL as well, as stated above..... Is yours on??

 

when cranking does the rpm's go up at all

 

I am having the same problem... Long hard starts.. I mean long... Then miraculously it fires... I thought it might be a VP.. idk any more info??

 

Yes, a bad crank sensor like everyone above said will cause your truck not to start. If the truck is not seeing any engine speed (rpm) it will not start due to not getting the correct timing. As for the VP, that is a good possibility. Get an OBD scanner and check your codes. If you have any of these codes P0216, P1688, P1689, P0215, P0251 - P0260, it's more than likely that your Pumps done. It that all checks out and you have no bad codes i'd replace the overflow valve on the VP and see if that fixes your problem.

 

I have replaced the overflow valve too and it seemed to help for the first day or so then went back to a hard start. Might have part of the problem though... I am kinda of doing trial and error on mine narrowing it down.. I have the filters to change then a new crank pos. sensor so if that dont help then its the vp. Mine is not throwing codes from the dash, idk about whats stored in there though... I did rebuild my fuel sending unit so that might help to, had tons of junk in there... Hope my situation might inspire or help someone.. Or if anyone has pointers for me please do.. especially the crank pos. sensor...

 

Just another thought but check your return lines near the back of the head. See if these are tight. Also the crank pos. sensor is behind your starter. I've never had it out but i heard it can be a pain to get to. The biggest thing though is if your reading RPM's while cranking i'd say its working the way it should.