engine running rough

[rusty79beast]

I just started up the blazer for the first time in about 2 months, since I had to replace the front seal on the transmission. The engine ran rough. For the first 45 seconds or so it was running great, but then began to stumble and finally stalled. It had quite a bit of black exhaust, so I am thinking part of the problem is that it is running rich. What else could it be, and how do you go about fine tuning the carb on a 79 blazer, 350, with a quadrajet carb? Which screw do you turn, and what else could help fix the problem.
Thanks in advance,
Paul

 

[4x4k20]

that sounds like your choke is hanging up. check it first it will cause it to stumble and run rough

 

[pauly383]

Anytime you have a vehicle parked for an extended period you must put fuel stabilizer in the gas tank to prevent fuel breakdown ( will basically turn varnish if left long enough ).
Also did you immediately shut engine down after it ran rough. sometimes it will smooth out after gas has been flowing through
everything for awhile. and yes you should check your choke like the other gentleman suggested.

 

[workingman]

Since you didn't say otherwise I'll assume you drove it or started it at least once after you put the trans back in and I'll also assume that it ran well. If this is the case it does sound like something sticking.

Check your vacuum hoses also. Make sure to check the small one going to the choke (If I remember correctly) its about 2" long on the side of the carb. Check the vac hose to the dist.

Check for condensation under the dist cap (I'll vote for this one as being the reason).

Run some (maybe a lot of) carb cleaner through the carb bowl vent slowly while its running and have your hand on the throttle because it'll want to kill. Use the spray can solvent kind - I think STP brand. Some carb cleaners are more polar and just don't work well. This may help to free up anything internal.

Reply back if this doesn't work
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