Distributor - Dorman

[muddog321]

Time saver note:
Anyone replacing their 98 up plastic based distributor due to stripped cap holddown threads or clogged vents causing the cap to fail by pressure forcing oil up into the actual casing thru the pins resulting in random misfires (some new caps come with a warning on clogged vents) - Dorman has a metal base model #690-900 that solves these problems and comes complete with pickup, cap, and rotor for 95.99 at Advance (lifetime) and by searching you can find on other sites. Rebuilt plastic based distributors have recast plastic holddown areas that have failed for me after a few cap/screw removals.

When installing read "How to find Top Dead Center and set your distributor and rotor when it has been out" by drdd in the Tech Section. If you install one tooth off it idles well but acceleration is bad and it will run hotter (timing off).

The #1 easy/cheap fix for any 98up Blazer owner when it runs rough, slow accel, or quits running is to replace the distributor cap due to internal failure and this is a good longterm fix. This assumes your fuel pump/pressure has been ruled out as the cause and I rate that as #2 on the Blazer run rough/bad start/no run guide.

[old_master]

I've installed several of those.... very substantial part, except for the cap and rotor. You're much better off sticking with an AC Delco cap & rotor. The easiest, fastest and most accurate way to make sure the distributor goes back in correctly is to manually rotate the crankshaft clockwise until the rotor lines up with the "6" on the distributor housing.

Then remove the old distributor and install the new one making sure the new rotor lines up with the "6" again when it's fully seated. You might have to rotate the oil pump drive slightly with a screwdriver to get the new distributor to fall into place. After it's in, check camshaft retard with a capable scan tool, and adjust the distributor to achieve 0 degrees. Retard it 2 degrees if you want better high end power, advance it 2 degrees if you want better low end power. About a 30 minute job and makes all the difference in the world!

[laxman21]

Originally Posted by old_master

Retard it 2 degrees if you want better high end power, advance it 2 degrees if you want better low end power. About a 30 minute job and makes all the difference in the world!

Interesting, what would give you better gas mileage?

[old_master]

Originally Posted by laxman21

Interesting, what would give you better gas mileage?

If you're looking for better power, your fuel mileage will suffer. Power or fuel mileage, you can't have both. If you set camshaft retard to zero degrees and drive it civilized, you'll get your best possible mileage