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Bad cam sensor?

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Old 08-07-2016, 11:10 AM
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Default Bad cam sensor?

My code reader is saying there is a problem with my cam sensor. Symptoms are as follows;

Rough running after it warms up at certain rpms. Maybe 15 minutes of driving. It feels like the timing is being retarded.

Underpowered.

Sometimes dies very abruptly at idle.

Occasional misfire sound but no code), meaning that I hear gas flaming in an open cylinder.

I've read this could be the crank sensor. I've also read that the MAF can be an issue. I have all three sensors in my parts pile but the cam sensor is a real issue because my crank pulley fits TIGHT. Any opinions?

I cant recall the code... p0340 or 390.

Best,

Charlie V
 
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Old 08-07-2016, 11:11 AM
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Oh, notably it only happens when it is warmed up and I have checked all of the wiring to the three sensors and see nothing amiss.
 

Last edited by Charlie_V; 08-07-2016 at 12:16 PM.
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Old 08-07-2016, 12:50 PM
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but the cam sensor is a real issue because my crank pulley fits TIGHT
Cam sensor access looked pretty good to me with water pump removed.
......
 
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Old 08-07-2016, 02:52 PM
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Originally Posted by number9
Cam sensor access looked pretty good to me with water pump removed.
......
I just replaced the crank sensor and am about to move on to cam. I think you're right. Looking at it, that would be the best way.

Unfortunately I do not think I can get it out without removing the water pump, though I may try, but that is preferable to removing the main pulley in my circumstance (pulley fitting very tight over crank). I had hoped not to lose any fluids but c'est la vie.
 
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Old 08-09-2016, 12:03 PM
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I haven't fully resolved this yet so this is a quick follow up for the benefit of anyone else having this issue.

I replaced the crank sensor with a new one I already had and the truck ran great on a 10 mile test drive. The next day, I had a three hour trip so I threw caution to the wind and took the rover. Bad decision. After about 30 minutes I was getting hesitation again and it died at a stop. I pulled out my code reader and had no cam code (so that was bologna) but now had an MAF code and the dreaded p1884, which tells me nothing but is generally associated with MAF problems. I considered unplugging the MAF and just getting 5mpg but toughed it out and and made it home.

The troika of MAF, cam sensor, and crank sensor have a lot to do with timing. I didn't replace the cam sensor just to take a little more scienbtic approach, and I am glad I did. I don't think there is anything wrong with it. This afternoon I'll put a new MAF in and report back after some driving time.
 
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Old 08-13-2016, 06:15 AM
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Let us know how this turns out. I too have a P0340 issue. For a while, it was only on cold start up, but is now on every start up. No codes while running and driving, and no real engine issues, save for a slight "lean stumble" at idle at a stop light. I'm guessing a timing and oil pump set are in my near future, but with our recent move, working on the truck is an issue.
I'm curious about how you resolve this, especially because your case seems more "advanced" than mine: my truck hasn't quit on me. At least not yet.
 
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Old 08-13-2016, 11:59 AM
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Originally Posted by NickAdams
my truck hasn't quit on me. At least not yet.
P0340 Camshaft position sensor circuit malfunction - Open/short circuit to vehicle supply or earth
Advanced warning system. Sensor going tango uniform or circuit issues likely.
......
 
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Old 08-13-2016, 04:27 PM
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I like that: tango uniform. That would be sanctionable in today's military. Hahaha

Number9 may be right, but I did get full relief with an MAF swap. No codes or pending codes. I'm not even sure I needed to swap the crank sensor. But I have another cam sensor and next time I work on the front I will swap it out.
 
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Old 08-13-2016, 07:53 PM
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Originally Posted by number9
Advanced warning system. Sensor going tango uniform or circuit issues likely.
......
Those babies are expensive. Anyone have experience or luck cleaning one that has 220K miles on it?
 
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Old 08-13-2016, 11:10 PM
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Originally Posted by NickAdams
Those babies are expensive. Anyone have experience or luck cleaning one that has 220K miles on it?
Nick, I've changed mine before and as far as I know it is just a finely tuned magnet. I set mine on the ground and it got tiny metal flecks on it. I got them all off with a rag and a stronger magnet.
 


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