how to install distributor on 97 sonoma

[uknow14]

does anyone know how to set timing on a 97 sonomoa w/ 4.3. I just bought a new distributor the truck is still running , but has a slight miss .

[Hammer Head]

Could be off a tooth if it's really rough.. if just a small miss turn the distributor ever so slightly.

[Mikz86TA]

To correctly install: First start by hand turning crank and get the #1 piston to top-dead-center (remove all plugs to make this easier). there are some tools to aid in this like from EaswoodCo. Jegs or hold finger over plug hole on #1 and when the compression of TDC reaches youll know it. FYI #1 is front left drivers side. Next after this is accomplished, drop your distributor in with the cap off(leave plug wires attached to cap and mark which one goes to #1 cylinder. Your pionter on the rotor will rotate as the cam gear engages the drive on the dist. shaft. Using your cap/plug wire #1 as the reference, mark the base of the distributor(where cap-dist meet). Pull cap off and see if the pointer lines up. If it is very close, you can rotate the dist. to line the pointer and mark up. If it is closer to the next cylinder wire, then pull dist out and re-engage the gear another tooth or two over. Once you line the two up, tighten your dist. base and reinstall cap/plugs/wires. On that truck if I am not mistaken, the computer will set the timing, but it needs to be close on install. If you still have a miss and know the dist is on, you might have a fouled plug, defective wire, bad coil or module. Plugs you can check by sight. A wire you can watch for an arc from a cut/burnt through or worn through at night while motor is running. Look for white marks on plug wires in the light and watch that spot(s) in the dark for arcing of current. Wires can wear while rubbing on other parts, develop a tiny split from age and arc to ground. A coil or module is just easier to relplace and see than most people to test. A good multimeter and a Chiltons can show you those test prcedures and results. Good luck, hope you find it =)

[rat]

You will get a crank cam correlation code if it is off a tooth, and it will run like garbage.

[warp9pnt9]

Jegs or hold finger over plug hole on #1 and when the compression of TDC reaches youll know it.

Jegs? What's that? How will I "know it"? A little more description, please. I've fouled up my distributor position (forgot to mark it) so I'm just trying to learn to set it right from scratch.

1997 Blazer ZR2 using CSEFI (NOT TBI, MFI or CSFI), let me know if it makes a difference.

Next after this [TDC#1] is accomplished, drop your distributor in with the cap off...

Do I turn the distributor so it aligns with plug position #1 before dropping in?

(leave plug wires attached to cap and mark which one goes to #1 cylinder. Your pionter on the rotor will rotate as the cam gear engages the drive on the dist. shaft. Using your cap/plug wire #1 as the reference, mark the base of the distributor(where cap-dist meet). Pull cap off and see if the pointer lines up.

Do I turn until TDC on another cylinder? Do I cycle through all six TDCs and back to TDC#1?

On that truck if I am not mistaken, the computer will set the timing, but it needs to be close on install.

Does my truck automatically set the timing? :) If not, what's next, buy a timing gun and a stop watch, get a pad of paper, pencil, and eraser, and take notes? :p

Thanks.

[MikDee]

Jegs is an online speed shop, with tools also.
Ok, Once you have found TDC for Cyl #1, not Cyl #4, on the crank, by using your finger to find pressure at the #1 spark plug hole, as it's coming up to TDC.

The dist. body should have come with a mark at the base, this mark should line up with a mark already on the manifold a #(6). If not, the dist body needs to be set so that, the spark plug terminals on the flat cap are facing exactly to the sides of the truck. This is where you want the dist. body to end up once you're done.

With the crank set at TDC for #1, take out the dist. and then put the rotor right where #1 spark plug terminal is, and drop the dist in, while holding the dist body approximately in place, if it doesn't settle in completely, you'll hafta pull it back out some, and rotate the rotor a little bit at a time, in a clockwise direction, as you try to fully seat it,,, do this till the rotor is lined up as close as you can get it to Cyl #1, you will get there eventually (what's happening is, you are moving the oil pump shaft a little at a time, by doing this, to mesh with the dist gear. (I know it's a pain in the a$$), but don't give up till the body of the dist, and the rotor are both in the right place, your timing should end up being right on this way, as long as the crank, & cam, are on TDC and set to fire Cyl #1, not Cyl #4, from the beginning.

I'm assuming if the truck is running, before you do all this, when you set TDC on the crank, your rotor should be near Cyl #1, and your dist body is close to where it should be, it should only take a bit of tweaking to get it right now.

[Sparky2263]

http://s10planet.com/forum/showpost.php?p=51443&postcount=10

[warp9pnt9]

You will get a crank cam correlation code if it is off a tooth, and it will run like garbage.

Of course, I'm almost afraid to ask, but any chance of Bad Things (c) happening if I'm waaaaaaay off (or even a little off), like explosions, clanking, knocking, deformation of moving parts? In other words, irreparable damage?

Thanks for the tips MikDee, I'll give it a go when I get to that point in my reassembly.

[Sparky2263]

any chance of Bad Things (c) happening if I'm waaaaaaay off (or even a little off), like explosions, clanking, knocking, deformation of moving parts? In other words, irreparable damage?

Nope.

[warp9pnt9]

http://s10planet.com/forum/showpost.php?p=51443&postcount=10

Beautiful, reference diagrams too. I did search the forums for "distributor top dead center tdc" but missed that somehow. ;)