Today I took my 4.7 to a shop to diagnose my problem. Well they said everything seems to be fine as far sensors and grounds and 5v but the only thing they couldn't do was get the cam and crank sensor to sync togeather.

What do you think would cause this problem?? A bad pcm??

 

Does anybody know what would cause the cam and crank sensors to not sync togeather?

 

What reason did you take it to the shop, did you have a CEL/MIL or was the truck running rough?

 

I have had a check engine light on for awhile now that I try and fix every now and then and the cel is a p1391. I have put new sensors in both the cam and crank. I have checked for 5v and have good ground. I Missed with the pin outs on the pcm I have checked the wiring for shorts and melted or cut wiring found nothing wrong so I took it to the shop to see what they said. They said the timing is fine and the sensors and grounds are fine. They just can't get the sensors to sync which is why my cel is on and I have I hesiation around 2500 rpm's. They could hook up a scope on it but they would have to charge 75 an hour and don't know how long it would take to go threw everything so it could get expensive. They said they would reccomend taking it to a dealer who may have delt with situations like this before. I am not gonna take it to the dealer to have them tell me it's a bad pcm. Which is what I have been suspecting since that is my last option to try. Unless I have over looked something, which is why I asked if anyone has every delt with them not being able to sync the cam and crank sensor togeather and how they fixed this problem.

 

Alldata doesn't list bad computer as a possible problem. Doesn't mean it isn't so.

I have dealt with this problem 4 or 5 times, Everytime turned out to be a bad sensor.

Is it possible that you got a bad crank or cam sensor when you replaced them? Double check the tone wheels to make sure there isn't any grease. Make sure all the connections are snug and none are corroded. Check areas of wire that may be close to heat sources, keep in mind wires heat up resistance goes up. Also check for possible sources of interference, IE wire running along side spark plug wire.

Maybe your local auto store has one you can rent, This is an extremely difficult problem to diagnose without a Scope. and I wish you good luck.

 

Wouldn't the vehicle not run if the sensor was not working right. Mine starts up everytime just has a miss or hesitation around 2500 rpm's then acts normal again. It did the same thing with the old sensors so that makes me think that the only option left is to get a new pcm. I have ran my fingers around the wirng and have even tried wiggling the wires to see what happens nothin seems to make it get worse or get better. In my haynes it says to check volts at sensor and check ground and if everything is correct you will have to get you pcm checked out. I am just so tried of missing with this problem. And don't want to pay a dealer a bunch of money for them to tell me it's the pcm when that is what I think it is. But I might just have to bring it to them if the new pcm doesn't fix this problem.