engine boggin and popping through carb

[scrappyk5]

lately when i start my blazer in the morning, about the first 10-20 miles or so i am getting a real bad missing and as i try to accerate its starts bogging and popping through the carb.the more gas i try to give the worse it gets. its starts going away after about 20 miles but is there just slightly, still lots of power though.
could i have water in the gas ?
bad plugs ?
cracked distrib ?
bad wire ?
is this a moisture issue ?

 

[lectric80]

Has the temperature in the morning been significantly cooler? If so you may be dealing with a spark issue, or a slight timing issue. Most likely a bad plug or wire is where I would start, since you don't seem to have the problem once it get's warmer.

Edit: It could also be a vacuum advance that is sticking in cooler temps.

 

[Greg72]

Backfiring through the carb can also be an indication of a flay cam lobe....hopefully it's not that.

If it goes away at temperature, odds are that you're chasing something else. I'd follow the suggestions to check the basics. Cap/Rotor/Wires, then maybe fuel delivery (filters, fuel pressure, etc)

 

[scrappyk5]

Backfiring through the carb can also be an indication of a flay cam lobe....hopefully it's not that.

If it goes away at temperature, odds are that you're chasing something else. I'd follow the suggestions to check the basics. Cap/Rotor/Wires, then maybe fuel delivery (filters, fuel pressure, etc)

she fires righ up in the morning and idles pretty decent. but realy is a bitch to drive for the first 10-20 miles. then she starts clearing out to almost perfect. still a hicupp every so often but lots of power. do not think its a cam lobe. i changed the filters yesterday to try that first. i think this weekend i will replace the plug wires which have atleast 70,000 miles on them. the cap has about 20,000 miles on it. the plugs have about 5,000 miles on them.
then see what happens.
i will try some dry gas too, just incase.

 

[Russell]

Sounds like she is running too lean in the morning. Check your choke, and maybe adjust your idle circuits to richen things up a bit.

 

[vortec]

Sounds like she is running too lean in the morning

x2

would account for the misfire and the backfire through the carb

check the timing, too.

 

[tvonloss]

Usually popping through the intake means your on the lean side of things or have some weak parts in the ignition. Are you running a good fuel filter? Some of the little circuits in the carb could be clogging up. if your getting a hesitation/bog without a missfire your almost certainly running lean for some reason.

 

[scrappyk5]

I will check things out guys and replace as needed. i put some cleaner in the tank and changed the filters. like i said before, its bad when i first drive it in the morning. it does clear up about 90% but still does it after warm up and in the afternoon. its seems to do it alot more under load than if i have the engine at a higher rpm. i will set my timing after i change the wires ,plugs, and cap.
thanks all,
mike