I had a very similar problem recently. I found that the gear on the bottom of the distributor was worn out. I had a miss at highways speeds while cruising but it ran awesome if you put the pedal to the floor. It would hiccup and jerk when trying to shift from 1st to 2nd on the first drive of the day but got slightly better after it warmed up. I had a code P0300.

I pulled the distributor cap and twisted the rotor to test the play and it was sloppy. I pulled the deistributor and found indentions on the teeth of the distributor gear. I picked up a lifetime warranty replacement distributor from Orielys for $90 and it resolved all of those symptoms.


EDIT: I would not buy just the gear...it was half the cost of the distributor and I don't remember the gear having a lifetime warranty. The distributor from Orielys also came with the camshaft position sensor.

 

Sounds like my 99. Does it do it cold and or damp weather? I cleaned the cam position sensor and crank position sensor. Does it look like you have rusty dust inside your distributer? I think that dust screws up the cam sensor. Just my opinion. I have 161,000 on mine. I also took the MAF off and cleaned it.

 

i just tryed a new coil and it didnt help it at all. it does it when it wants to. today it was real nice weather outside and it didnt miss or nothing at all but wat i dont get is, the engine light has been off the whole time its been missing and running like a$$ but today it was running great and the dang engine light came on.WTF?? im gettin sick and tired of messing with it idk what to do next. where are all these maf and crank sensors at u speak of because idk what any of them are i just see diff sensors here and there and idk what they all are


sounds exactly like mine, but if its wet and rainy out it wont get any better as the day goes on. and sometimes it wont do it at all just when it wants to be a D**K

 

Ya mine does the same thing it happens with or without the light and mainly on cold or rainy days. On nice days it runs great. you can go all day then all of a sudden at highway speed it just starts missing. I just replaced the cat so Im hoping. The crank sensor is easy to remove. You need a 8 or 10 mm socket cant remember which size. It is located at the front of the engine on the bottom near the oil pan. It has a gold color bracket holding it in. I was told if it has a burn or discolored area on it it will act up. Mine was fine but the info was taken from a guy with a different make model GM car but was a 98. I dont know if it would help but worth atry. It only took like 2 minutes to remove and inspect and reinstall. The cam position sensor is what is in the distributor it is easy to remove as well its under the rotor. I just used some cleaner and compressed air to get the rusty dust off. I live in Ohio and my problems didnt start till it got real cold and nasty outside. The blazer ran great till right after Christmas then it was nothing but a pain.

 

is that crank sensor in tha same spot on a 4wd as a 2wd cause mine has that big skid plate and all that is in the way so u really cant get to it. also its all different on a 4wd cuz the tranny is different and makes some stuff not the same as 2wd's

 

The only difference between a 2wd engine and a 4wd engine on the 2nd gens is the oil filter location. Everything else is the same.

The only difference with the transmission is just in the tail shaft and that the 4wd transmission does not have a tail shaft. Everything else inside is the same there as well (considering like years).

 

Hey all I replaced my cat converter that was rattling, cleaned the rusty dust from the cam position sensor and pulled the crank position sensor and checked it. The crank position sensor looked alright except for the grind marks on it. I did reinstall it since they are $70. Im not having problems with misfire again the light has stayed off and Im getting 18 to 20 mpg at 55 mph. sometimes 22. Im hoping it is fixed. I think it was the rusty dust in the distributor so check yours maybe it will help. rust is magnetic to a point and I know dust will mess with electronics. I pulled the distributor and cleaned mine with wd40 and compressed air. It could have been my cat converter but it acted up after I installed the new one. I had the misfire when it was cold or rainy and in thye morning when there is dew on the ground. It was rainy out yesterday and it ran fine and it did alright this morning. Hopefully this helps the rest of you with this problem. Now my fn ABS light is coming on but I can get OE hubs real cheap under $100. I dont trust the aftermarket hubs at all. I work in a place that imports them and I am the so called engineer that measures them up agains OE. I dont have all the proper test equipment to do a proper test on them so??? Well any way try cleaning up you sensors before dumping a bunch of money into your 4.3. Mike

I also cleans up the MAF sensor with compressed air about 70 pounds real carefully sinse you can break the sensor with to much pressure.

 

thats what im getting right now with it missing and all that i got a 15gal tank and i get 290-310 miles per tank mainly 90% highway 10% city

 

I have the same exact problem. Changed plugs, wires, Dist Cap and MAF. Changed the MAF because when unpluged the missfire went away. When I put new MAF in it ran fine for a couple days then came back.

Help!!

Did you find out what the problem was 98blazr??

 

you could always install a lift kit, then you can sit at each front wheel in turn and remove the plugs no probs- maybe a bit overkill but just a thought.
hope you get it sorted soon,ive had mine 8 yrs and they can be a pain in the *** sometimes.
goodluck.