Missing on Start-up?

[nau81blazer]

Hey everyone,

Just wondering, my truck does a funny thing when it starts up. Right when if fires up for the first time in the day it will run normal and idle fine for about 5 seconds. Then it slowly starts to miss and idle's very rough for about 2 min until it warms up and evens out again. Any ideas about what could be causing this? Just wondering really, just changed cap and rotor in the dist...What do you guys think? Thanks for the info.

--Adam

 

[k20]

did it start after u put on the new stuff? Got 2 wires on the cap backwards maybe?

 

[Stoopalini]

Sounds like it could be a choke problem. Do you have an electric choke? If so, try unplugging the ground from it and see if it does the same thing.

Thomas.

 

[Can Can]

Yup. Sounds a lot like a sticky/poorly adjusted choke to me, too.

Pop off your air cleaner. Set the choke/high idle cam by depressing the gas pedal to the floor. Before you start the truck, get out and check to see how your choke plate is positioned on your carb. It should be pretty well shut tight.

Now go start the truck. Scamper back to the front of the truck and observe the position of the choke plate. It should have opened up just a hair(about 1/4" or so). To see is you're choke is set too rich, open up the choke plate a wee bit when the motor starts bogging down. If the idle smooths out then you need to lean out your choke.

If the plate/linkage is hard to move you may just need to do a little cleaning to free things up. While you've got the aircleaner off I recommend getting a can of carb cleaner and spraying down all the linkages on the outside of the carb. They get gummy over time and can lead to problems like those you're encountering.

I hope that makes sense. Let us know what you find out.

 

[nau81blazer]

Cool, I'll definately try that stuff and see if that's what's going on. And it was doing the same thing before I got the new cap and rotor. This carb is giving me all kinds of trouble and has for a long time. Hopefully it just needs a good cleaning. Thanks for the help guys!

--Adam

 

[nau81blazer]

Hey again,

Back from the dead here but it finally stopped snowing so now i can work on it. When you talked about leaning out the choke, how do i do that? I have an edelbrock with an electric choke. Thanks again for the help!

--Adam

 

[the fall guy]

assuming the edelbrock is similar to the holley...on the right side of the carb is the choke coil. it should have about 3 screws on it. loosen the screws a bit and turn the choke cap clock wise for more choke and counter clockwise for less. Use the markings on the cap housing and cap as referance points.

hope this helps.