I have a 2004 3.9 Mustang and about 10 months ago the valves started to ping/ spark knock/rattle so I just ran 93 octane until I had time to mess with it. The 93 octane used to completely quiet it and now it’s loud after the engine is warmed up with any load on it, even with 93 octane. Its throwing a p1336 (cmp misaligned. But the code definition is, ckp and or cmp input signal to the pcm concerns.) I’ve changed the crank and cam sensor and the cam sycroniser assembly. However, when turning the crank sensor, the timing doesn’t change at all. What could be the cause of this and the fix to it? Thanks.
It is possible that you have a bad knock sensor. The computer advances the timing until a faint knock is detected, if the knock sensor stops working, it will advance the timing too far. The crank sensor does not set the timing, it only tells the computer where the engine is at in rotation. The computer uses that as one input for the timing. There are other inputs as well including the knock sensor.
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I think it’s probably what Keith mentions, faulty knock sensor. But there are other things that can cause pinging, presuming that’s actually what you are hearing. For example if the cooling system isn’t doing its job, that will often cause pinging, especially under load. Could be something as simple as an air pocket in the cooling system. Have you had any work done involving the cooling system? Do you have to add coolant occasionally?
The code indicates the computer thinks the cam position sensor (or crank sensor) output signal is erratic, not what it expects. So what I’d do in this situation is bring out my o’scope and take a look at those sensor’s signals. If one of them is misbehaving, could be a faulty sensor, but just as easily could be a faulty electrical connector, wiring harness problem, faulty shielding, or high resistance ground. Make sure the battery negative has a good non-corroded connection to the chassis, likewise the engine block to the chassis, and the cylinder head to the chassis.