Workhorse chassis, 7.4 V8 454. Had an extended crank, and it didnt catch, turned it off and restarted and fired right up. Service engine soon light came on. Stop at a repair shop and they got a code for the crankshift position sensor. Also a 1 and 4 ignition coil. He told me the coils could be in relation to the csp. In clearwater, fl heading to disney then back to nort westeren il. The engine fired right up after cooling all night. It is not missing while running. Running as smooth as it had the last two days. Not sure if I should worry about it here, or finish my trip and get it fixed at home? Any suggestions??

I have seen engines get a fault code like you described, why it didn't start right away may never happen again, clear the codes and see if they return. I would not worry about it. All those electronic controls sometimes act just like my personal computer and "get a mind of their own" and it never happens again. I hope this helps, Bill

Might have been a one time hiccup or the sensor is starting to fail. When it fails you will need to be towed. If you have time while in Orlando and the kids are enjoying It's A Small World take coach somewhere and get it replaced along with the coils. The sensor is part of the ignition timing loop. Without the sender the system does not know when to trigger the spark plugs to fire. Replaced the mechanical distributor.

You had a no start event and you have a trouble code that indicates a problem with the crank position sensor or the circuitry to it. From my experience, I would suspect that you will have trouble with it in the future. These issues don't generally heal themselves. When it will fail again is anybody's guess.Did your shop run any test on the senor/circuit? A simple resistance test at the PCM connector will often lead to the source of the problem.

Thank you guys for the replies. No other tests were ran. He just told me it may fail tomorrow or never again. That he could search for more issues, but it could take hours to diagnose, that he would rather have it come to his shop dead as it is easier to troubleshoot then. He said to watch for it running sluggishly and for the sevice engine light soon to flash. Amd if it starts flashing to pull over as the vehicle could shut down even if I am doing 70 going down the road.

If the engine has sequential port EFI, that position sensor also signals the fuel injectors when to squirt. Depending on how it fails, you may get fuel flooding and a potential for a fire.

Crankshift Position Sensor???? | Good Sam Community

13 Replies

psmoore
Explorer
Jun 22, 2013
Got one bought today, and will probably wait until I get home tomorrow unless I have trouble. The mechanic showed me where and how. Looks like a fairly quick job.
John_Wayne
Explorer II
Jun 22, 2013
Haven't checked but there is probably a you tube video on how to change it your self.
barnaclebill
Explorer
Jun 22, 2013
Airstreamer67 wrote:
I would put a new CPS in and keep the old one as an emergency get-me-home spare. That's a cheap fix, and can save a lot of headaches in the middle-of-nowhere.

That is good advise. Replace it at your leisure, in a safe place and not on the side of the road!
Airstreamer67
Explorer
Jun 22, 2013
I would put a new CPS in and keep the old one as an emergency get-me-home spare. That's a cheap fix, and can save a lot of headaches in the middle-of-nowhere.
rode2nowhere
Explorer
Jun 22, 2013
glad you made it, electronics on cars can be a pain, may throw a code for one thing and could be something else.....
psmoore
Explorer
Jun 22, 2013
Had a guy come out while at Disney, and he cleared the light and no lights come back on and we drove all day today with two re starts. It does appear to be getting longer to crank but it cold be that I am paranoid about itnow. He said I did have a liitle oil leak around the seal of the sensor. He did show me where it was and showed me how to fix it, now just need to find an auto pars store so I have one in the RV.
ScottG
Nomad
Jun 16, 2013
Electronics rarely fix them selves. I would replace the sensor now if it were me so I don't have to worry about it failing completely on the way home.
PapaSmurf947
Explorer
Jun 16, 2013
Have a '97 3500 Sierra with the 454. Died sitting in the drive thru at Sonic. Mechanic across the street did a quick diagnosis and said the positioner was bad. Went next door to parts store and bought the part and he installed it in about 2 minutes. Total cost less than $100. If you know it is starting to go, that is a cheap fix compared to crapping out in the middle of nowhere.
frankdamp
Explorer
Jun 16, 2013
If the engine has sequential port EFI, that position sensor also signals the fuel injectors when to squirt. Depending on how it fails, you may get fuel flooding and a potential for a fire.
psmoore
Explorer
Jun 16, 2013
Thank you guys for the replies. No other tests were ran. He just told me it may fail tomorrow or never again. That he could search for more issues, but it could take hours to diagnose, that he would rather have it come to his shop dead as it is easier to troubleshoot then. He said to watch for it running sluggishly and for the sevice engine light soon to flash. Amd if it starts flashing to pull over as the vehicle could shut down even if I am doing 70 going down the road.