Install distributor

astro
chevrolet

#1

How do I install a new distributor on my 98 astro van? Sticker under hood says I cannot time this model. How do I get the new distributor installed in perfrect timming?


#2

You need to buy the book. You don’t say what engine you have, but you would start by making sure the number one cylinder is at top dead center. Then you would point the rotor at a mark (generally an arrow or a dot) on the distributor housing. Then you would seat the distributor so that the final set position of the rotor points exactly at the timing mark on the housing. It often takes a few tries.
Then, you may be 180 degrees out, meaning that the distributor is mounted now exactly opposite where it needs to be aligned. In other words, you have a fifty-fifty chance using this method to get it right the first time. The reason for this is that the number one cylinder comes to top dead center twice in a full intake and exhaust cycle. If you try to start the car with the distributor 180 degrees out, it will likely do nothing, not catch at all. But it might also backfire, which with all the fine electronics along the way to your tailpipe, not to mention the valves, you want to avoid getting it wrong.
So get the book. There may some information that will help you set the distributor the right way the first time.
If you ignore me about the book but not about the installation, and the engine won’t start and/or backfires after installation, then you would rotate the engine until the rotor now points exactly opposite the mark on the distributor housing, and then remove the distributor and realign the rotor to the mark.
But buy the book.


#3

Have you already pulled the old distributor out?


#4

Remove the cap and carefully observe where the rotor is pointing in the OLD distributor. Install the new one in the exact same position…

In modern engines, the TIMING is not controlled by the distributor…


#5

no


#6

DIYers sometimes get bent out of shape when the distributor won’t fully seat due to the oil pump drive but at this point we don’t know if the problem is resolved or the poster has thrown up his hands, Caddyman. Oh well.


#7

Well, good. As Caddyman instructed remove the cap and observe, or better yet mark the rotor and distributor housing with a crayon, etc. I believe you can see the base of the distributor so you might mark it and the intake to get that back just as it was. But the critical “timing” is the relationship of the rotor to the distributor. After marking, remove the old distributor and transfer the markings to the new one. When installing, allow for the gears to mesh and allow for the distributor not fully seating.


#8

one way to get the timing right from the get go is to remove the valve cover. remove the number one spark plug. Turn the crank by hand (with a wrench on the harmonic ballancer bolt) till a bamboo skewer in placed gingerly in the no. one cylinder is at TDC, and the timing marks on the crank and block line up at 0 degrees. Check to see that both valves are in the closed position. Use a scribe to make the block for the position of the distributor, and the position of the rotor. Only now remove and replace the distributor and line it up as per the old one. This way you will know that the timing is right.


#9

I could be wrong, but the crank position sensor tells the ECM when to fire the plugs. The ECM controls the timing, not the distributor…True, the rotor must be pointing at the correct contact post in the cap, but it’s not critical as the actual TIMING is being controlled by the ECM…

If the distributor contains a pick-up coil and control module, then it is controlling the timing and the timing can be set with a strobe light in the normal fashion by rotating the distributor slightly…