Chevy Blazer Misfire

paulh6

Hot or cold, most of the time it misfires, sometimes it actually drives smooth. I even went on a day trip to another town. It drove smooth the whole time! Usually, though, the opposite is true.
This has been an ongoing problem. New cap, wires, plugs, EGR, TPS. _lots_ of fuel system cleaner, and none of these things have solved the problem.
If I punch it, it will get up and go. (It seems to do just great~ that's why I was hoping the TPS was to blame...)
It's when I drive "normal" that it acts up.
Ideas?

thesandman7

i had a similar problem some years back with my 2000 Blzaer. replaced the same items and even went as far as reploacing the distributor assy. turns out that i was getting moisture inside the cap from a crack in it. check ur distributor for cracks or make sure the seal is good on the cap/distributor

jlflemmons

When you changed the wires, did you also change the coil to distributor wire? The routing of this wire takes it against a metal bracket, and can damage the insulation causing a misfire.

punshka

Good Morning,

We are seeming to have some of the same problems as you've listed above. If you wouldn't mind taking a look at what we've posted this far, to get somewhat, of an idea of what we're talking about, that would be great. We're looking for some ideas on the issue that is at hand. Please let me know if you've got any suggestions on this issue.

Thank you.

punshka

It's about 9:20am here and it seems that everyone has fallen asleep. If anyone has any kind of feedback to our issue at hand, please feel free to let me know. Thank you everyone for all of your help and efforts. We'll talk soon.

paulh6

Here's the thing. Since it has become MUCH colder here, the problem has all but vanished. Ideas?
I chalk it up to being a self healing Chevy, but I'm sure there is a much better, mechanical or electrical explanation.
I hope this will help pinpoint whatever was making it act like it had "pondwater" for fuel.
Oh~ I also quit using WalMart's fuel. Related?
I only bring this up, because I used to drive @ 60 miles per day, and that is where I would get my gas. (plain unleaded) Then when I got my new job here in town, it sat for months. As I would only drive it now and then, it would have taken a long time to remove the deposits that cheap fuel would leave behind.

Just grasping at straws here...

punshka

Thanks for the update. I will let you guys know by this afternoon.

naddan

My wifes 2000 blazer started to have a pretty noticable misfire in the past couple months. It has a bad hesitation while accelerating around 2000 to 3000 rpms. I first replaced the plugs and wires. Then distributor cap and rotor , the ignition coil, the maf and now the spider injection. Nothing has aided the problem in the least. I was throwing a cel which was the amazing "P0300". I have also looked into any vaccum issues (I have found none). Im wondering if anyone has any input on my issue? Ive been fighting this vehicle and so far its winning.

naddan

I was also wondering I have not done a fuel pressure test, could the fuel pump possibly be weak? I was thinking that it may lose pressure when it gets to 2000 rpm due to a weak pump?

naddan

I failed to mention this is an intermittent problem that seriously happens at random. The vehicle could be hot or cold when this issue comes into play and will last for as long as days. It may stop for a day as well. That ruled out a compression or timing issue to me.

mtlwiz

had the same issue on a 96 and a 99. believe it or not it turned out to be the coolant temp sensor. it was messing with the electrical system.