Due to the shaft bushing wear I needed to replace the original GM plastic housing distributor in my '02, so I bought one from White Performance & Machine in Kingsport, TN.

Price was only $50 including shipping...so I was a bit concerned..???

Came 100% complete with everything ready to drop-in. Only difference I noted was that the cam gear had a wider oil pump driveshaft...tooth?....so it was a tigher fit requiring the oil pump driveshaft to be lined-up exactly or it would not drop-in all the way.

The distributor cap has bronze bushings around the hold-down screws and of course the hold-down screws go into aluminum instead of plastic....but still need to be careful to not over tighten and strip-out the aluminum threads.

Made all the electrical connections...time to give it a try...fired right-up...everything good. Let it run for 5 - 8 minutes or so...no missing, no check engine lite....but I wonder if I need to get a cam relearn done since it is a new cam sensor??

Just thought I would pass this information along to anyone else needing to replace the original plastic housing GM distributor.

Later....

 

Camshaft retard is not a "relearn", it is a physical adjustment that is made. When the distributor is installed, camshaft retard needs to be checked and adjusted, (it's part of the job). Installing the distributor is a "rough" adjustment, and DTC P1345 must not be present after the install. Adjusting camshaft retard aligns the camshaft position sensor with the camshaft. The adjustment is done by rotating the distributor while viewing camshaft retard on a capable scan tool. Desired spec is zero degrees, (perfectly aligned) with a tolerance of + or - 2 degrees.

 

Sorry used the wrong term....was typing too fast and not reading what I wrote.

I will need to find someone that has the proper scan tool...as I sure do not.

Time for me to start calling-around and finding someone that knows about this....have to make sure I use the correct term this time.......thanks Capt'n.

 

Had the cam retard timing checked....scanner showed -1°; tried to adjust to zero, but just no movement in the distributor housing with the hold-down bolt loose.

Since within tolerance, just going to leave it for now. Engine seems to be running just fine.

 

Almost perfect, I agree, leave it alone. The factory hold down bracket will only allow ~11 degrees of total adjustment, we're not talking much movement here.

The camshaft and distributor rotate at half the speed of the crankshaft: When you rotate the distributor to change camshaft retard 11 degrees, that same movement on an engine without EDI ignition, would change ignition timing 22 degrees. (Rotating the distributor on this engine does not affect ignition timing.) Adjusting camshaft retard aligns the sensor with the camshaft, hence the name, "camshaft position sensor". It's a "fine tune" adjustment for the sensor, that's all it is. It needs to be within spec, which yours is.

 

Not sure if I follow you;the distributor hold-down clamp slides into a square flange...for lack of a better term...on the distributor housing...this is what limits the distributor housing from rotating when the hold-down bolt is in the intake.
So how do you get 11° of total adjustment?

If the distributor is removed from the engine, then the clamp can be slide out of the square flange side it was in and put into another one, but this would rotate the distributor 1/4 of 360° which = 90°....but then the cam position sensor connector would be in the wrong orientation and may not even connect....and then the cam position sensor would be way off.

What is it that I am not understanding?

 

The inside diameter of the intake manifold hole, is slightly larger than the outside diameter of the distributor housing. The "slop" is what allows the distributor to move on an arc, when you loosen the hold down bolt.

 

I did not follow you at all.
I understand the intake manifold hole for the distributor is larger than the distributor housing....but the "slop" you refer to is only there when the hold-down bolt is removed. Even with the hold-down bolt loose...as long as the threads in the intake are engaged, the distributor housing movement is very, very little amount.

So I am still not understanding this ≈11° of total movement.

Could you try again.

 

That's exactly it, very little movement is all it needs. The bolt hole in the hold down is slightly larger than the bolt too, so along with the "slop", it allows the distributor to turn on an arc.

 

Okay got it.

I did loosen the hold-down bolt and tried to rotate the distributor CCW in order to get to zero for the cam retard. Again very little movement, so I just tightened the hold-down bolt and called it done.

My Blazer is running great with the new plugs, wire, distributor....just need to give it a really good cleaning now.