About a month ago I started getting a P1345 Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation Circuit Code which I know to monitor the (CKP) and the (CMP) signals to determine if they are in sync. The code is accompanied with misfires, poor acceleration, and a rough idle.

I assumed it was one of several things, either the gear on my distributor was worn, or one of the sensors was bad. The vehicle has about 160k miles on it, and I am pretty sure the distributor has never been touched in all those miles except for the occasional cap and rotor replacement.

I opened up the distributor cap and found that the rotor had a lot of play in it. I went to the auto parts store and found that I could get a refab distributor for 69.99, which was only slightly more expensive than buying only the replacement gear. I ended up buying the refab distributor instead of the gear, since it also came with a new sensor.

I swapped out the old distributor and found that the teeth on the old distributor gear were worn to a razors edge, nearly all the way through. Since the 2001 blazer has computer controlled timing, there is no real adjustment on the distributor housing. Needless to say I still marked everything up. When I dropped in the new distributor, I found that the oil pump shaft wouldnt engage when I was on what I thought was the correct tooth. If I rotated the distributor one tooth over, it would seat correctly, but my marks were 5+ degrees off, so I moved it back to what I beleived to be the correct tooth, and hit the starter to engage the oil pump shaft.

Afterwards, I reinstalled the cap and rotor, with fresh dielectric grease on in the wire boots etc. and fired up the car. It idled great, and sounded great, but when I took it out on the road, after a few miles i noticed a few misfires, and the code came back. Before long I noticed it started misfiring just as bad as before, and the acceleration seemed terrible. I went in and reseated all of the plug wires on the cap just to make sure I didnt have a bad connection somewhere, but the problem persisted.

I wouldnt call replacing the distributor a waste, since the gear was in terrible shape, but I hate that I am still stuck with misfires and a P1345 code.

So finally, here are my questions.

Is it possible I am off by a tooth on the new distributor?
Do I need to swap out one of the sensors?
Even if there is no timing adjustment on the distributor, do I still need to adjust timing using a computer?
What did I do wrong, or should have done different?

 

There is room for timing adjustment, read though this link.

https://blazerforum.com/forum/tech-a...-timing-24373/

 

I had previously looked at that thread, the timing adjustment at the end with the scan tool is what you are referring to? The housing of the distributor itself doesn't rotate like it does on older vehicles due to the computer controlled timing.

 

At the very end of the distributor, right by the gear you should see some little prongs that are moveable seperate from the gear. This will move the rotor without moving the gear itself, it only has about 15* of timing adjustment, IIRC.
It's kinda hard to explain, but if you look at it you should see it.

You would lift it out and hold the gear stationary and rotate it to advance / retard the timing.

 

Are you talking about the tang washer? I cant find any reference to that anywhere. Do you have a link to a pic?

FYP {fixed your post}
That said.. yes, you probably are off a tooth. Why anyone pulling a distributor should spend a lot of time on the net, and on youtube until they understand exactly how to do it and why.

 

Adjustment is done without doing anything other than loosening the distributor hold down bolt & moving the distributor body within the hole that it goes through in the LIM while monitoring the Cam Retard value via a compatible scan tool. This is how you set Cam Retard after first ensuring that the distributor is installed correctly per the first part of that thread. Rest assured that there IS movement in that location, enough for up to ~15 degrees of Cam Retard modification.

DO NOT modify anything on the distributor itself in attempts to adjust timing.

 

No, I didn't take any pictures or modify anything when I replaced mine.

The gears meshed fine, but my rotor was not pointing at my marks, tried over and over again to get it lined up, finally called a friend of mine that runs a shop and came over and showed me that you can turn the rotor just a little bit without turning the gear, dropped it back in and she fired right up and has been running ever since.

There is no adjustment possible by loosening the hold down bolt, the distributor body will not turn.

 

I have done it so I know this is false. The distributor doesn't turn, per-say, but rather, it moves in the hole through the lower intake which is enough for ~15 degrees of timing change to correct the CMP retard back to zero.

1st step in getting the distributor timed properly is aligning the two marks on the balancer with the appropriate references on the front of the motor.

I have used the process laid out in the tech article on a '95 (OBD2 w/ EDI distributor), '96, '98, '00, and just a month ago, an '04. All have worked perfectly fine except the '95 which had a slipped balancer outer ring which was somewhat fun to get timed correctly (that's where the ~15 degrees past TDC comes in).

I have 2 distributors in a box in the garage and neither have any "adjustment" between the rotor & the shaft. They don't turn. It's solid pinned at the bottom & a pressed fit at the top. If yours turned, it likely will end up with problems later. The rotor needs to be 100% fixed in alignment between itself & the gear at the bottom of the distributor for proper timing.