had a situation like that on my 02 blazer. on top of the intake pull off the connector and check the plug that goes to the spider(injectors) on the male side of the connector one of the pins was bent so it wasnt getting a connection on one injector. also check the inake its self and look for any cracks(mine had a little tiny one) anyway, it was giving me the po300 multi misfire and also o2 sensors 1 and 2 running lean. fixed the injector plug and replaced the intake and it runs like a champ. but deffinitly check the pins on the injector plug. could be just one out of place.

 

i think ive fixed it. put the rotor button on first since it was cheap and it has been running good since so ill see

 

well its been since my last post which was 4/9/09 i put the rotor button on and it quit all miss fire except for maybe a miss every once and blue moon only when cruise speed after over drive kicks in around 70mph.

But now as of 3-4 days ago its BACK!!! and doing it just as bad and prb little worse than before. i put a set of plug wires on it and it didnt help none. so in all ive put cap, button, wires and only thing that done any kinda help was the button. but now its doing it again.

this is agravating!!!

 

It is possible that the distributor is at fault, but have you tested the ICM and coil?

Are both codes still present?

 

how do i test the coil and icm? i unhooked my battery and the codes havent came back up it usually takes awhile for it to throw a code i havent had it come back on yet since i replaced the rotor button. until i broke the coolant temp sensor while changin plug wires but i got that replaced and the engine light went off

 

You remove them and take them to your nearest Autozone or Advance Auto. Make sure to test them repeatedly to get them hot.

You may want to pull the distributor and have a look at the gear on the bottom. If it is cracked or has any play between it and the distributor shaft, it will throw off the spark timing.

 

thanks man, do you think that a GM cap and rotor may fix it? should i get a new distributor or i found one from a junk yard for 50 complete with cap and rotor? it has to be something to do with the spark for sure, not to mention its worse after it rains.

 

If you were to know that the junkyard distributor was good, you can go that route. I would not reuse an old cap and rotor though. You may be surprised at how expensive a new distributor is.

 

yes a new one is very expensive, i can inspect the one from junk yard if i know what im looking for on the distributor for wear and stuff so i wont buy something worn out and junk, a new GM cap and rotor is around 55 dollars here at local gm dealer

 

$114 from Autozone which I would not consider to be terribly expensive.

If you find that the gear on the bottom of the distributor is worn hard or cracked, you can replace just the gear.

I have seen a lot of problems caused by worn distributors.