i think i have a problem but i dont know whats causeing it when im at light or half throttle my blazer seems like its boggin down but when i punch it to the floor it runs fine and i dont know what to do ive checked the vacuum lines ive checked the carb ive replaced the fuel filter twice the fuel pump twice changed the pulgs plug wires distributor cap and rotor button and ive also droped the fuel tank cleaned it and replaced the sock on the assembly and im out of ideas anyone know what it might be

 

what year is your blazer?
sounds like it's running too rich. how's your gas mileage?
How do your sparkplugs look?
Did you have the compression tested?
Does your exhaust produce any unusual smoke?
You can ask a buddy to drive behind you and see if there's blueish smoke coming out
when you put load on the engine.
That would call for worn out pistons/rings.
But probably it's just your carb. Have it cleaned in an ultrasonic bath and recalibrated.
Don't know what they ask for it where you live. It's like 100$ here.
Good luck

 

its a 1985
thats just it i dont know anything bout carbs and idk it wont go any further then a mile its a 4 speed and when its in first its fine but when i shift to second thats whewn it starts
the pulgs are brand new not even 3 days old
no i have done a compresstion test
not really just at fisrt when you start it up it throws a little while/blue smoke for like a second then it clears up
the guy i bought it from siad the carb was rebuilt a month before i got it but i took the car part 2 nights ago and it had about a 1/4 to 1/2 and inch of dirt and rust in the bottem of it i cleaned it and put it back together and its still doin it

 

Please list all of your vehicle information. You posted another thread in the Fullsize tech section which would lead me to believe you have a K5. Now, what engine do you have? What is the carb that is on it (2-barrel or 4-barrel, who makes it)?

If it is a Rochester Quadrajet, I just cured a very similar problem with my 74 Q-jet. The accelerator pump was failing to seal higher up in the bore so at light throttle changes, it would not squirt in the necessary fuel for proper combustion. During the rebuild process, I also found two of the bowl air bleed tubes had fallen off which was not helping the matters.

Blue smoke on start up is typically leaking valve seals. Does the truck use oil? Have you been keeping an eye on the oil level?

Timing can also be another area to look into. You should have the HEI distributor on your truck which is miles better than the old points style distributor, however, if the advance is not set up properly, it can cause a low RPM stumble.

 

sorry yes its a k5 its got a 305 with a quadrajet 4 barrel and what bout the choke i noticed that its not hooked up and i cant find the wire for it anywere oh and yes its electronic choke

 

Is the choke door closed all of the time? If so, that could likely be the cause of your problem. If so, let me know and I will see if I can dig up where the choke wire should come from.

But the problem you are experiencing sounds exactly like what I was going through on my K5. A rebuild of the carb cured my problem.

 

i drove it today i made sure the choke flap was open all the way and it run fine i found the wire the person i bought it from had it zip tied together with all the plug wires but now if i go wot with it it hangs open and i also think my front axle looks like is comin apart