Ok, I am looking for any help I can find on this one.
My blazer had a random multiple misfire.
I did a full tune up.. plugs, wires, cap, rotor, fuel filter.
It ran beautifully for one day..
On my way home from work it decided to throw the random misfire code, cylinder 4 misfire code... then bog down to the point where I had to get it towed home after stopping at a stop sign.
Next thing I did was replace the ignition coil.
After that I fired it up and it has not run well since. it is chugging and stalling out on idle.
Fuel pressure is at 60 PSI.
The only thing I can think of is the spider.
Any other suggestions before I dump about 400 into it?

 

UPDATE

Replaced the spider anyway... the original was bad at cylinder 4.
Started it up and still ran like crap.
Tailpipe was sucking in air.
I then ran a compression test and guess what...
Cylinder 4 was dead... 0 compression there.
My thoughts are that the injector was so bad that it flooded the cylinder with fuel.
That caused the exhaust valve to go bad.
I am going to rip the head out and check it.
New question is... should I send the head out to machine shop and have them rebuild it, or should I just buy new heads?

 

UPDATE!

After clearing the way and removing valve cover I found a broken rocker.
Ran a leak down test afterwards and discovered I still have a leaky valve.
Time to pull the head off and send it to a machine shop.

 

 

Well, I can't offer much in the way of help, but I hope you are able to get the truck running again. Thanks for posting your process on here. Maybe it will help others that run into the same or similar problems.

 

Well it's a long process. LOL. Hopefully I will not have to replace the block. May as well spend 2K on a new crate from summit if I have to. But when I get the time again to look more closely I'm going to check the piston seats for actual damage. I am hoping it is just discoloration from running bad. However with my luck it will be the worst side of it. LOL

 

WOW when it rains.. it pours.... now that my ZR2 has been down and sick for a while... my wife's 2000 GMC Envoy has decided to develop a fuel leak at the top of the tank.... JOY!!!!!!!!! LOL
And to top it all off... it's raining outside... so dropping the tank is out XD

 

My cars sit in the driveway and conspire to see which one will be messing with me this week. On a real quiet night I can hear them talking...

 

I know the feeling... the 97 Venture the 00 envoy and the 99 zr2 are always making strange noises at each other in the middle of the night.
We need to figure out a way to stop them!

 

I have found that my three Chevys seem to pick on the Ford Taurus...Maybe theres something there. As long as my wife keeps the Ford the Chevys do their best to look good.

Every time I fix something on that Ford it just breaks something else..(Chain Reaction) And I can hear the Blazer and the Truck laughing while the RV just sits there and tries to look innocent.