Quadrajet V8 carb problem

[craigvk]

The mixture screws were set when I first put the carb on. I have been adjusting the auto choke on the side of the carb. Turn it one way to richen it or the other way to make it leaner. The thing is, the choke valve closes when cold as it should but it runs like a barge until it's warm. It's like it can't evaporate the petrol quick enough as when I run it on gas, so when it's hot it can evaporate it no problem obviously because the heat makes the petrol go into vapour a lot quicker than burning cold petrol. :bang:

 

[craigvk]

Pretty much the auto choke isn't working at all I think.

 

[atrail308]

is your metal line from the manifold heating up your thermocoil in the choke??? Check for a blockage in that line, undo it from your choke housing with a 1/2" spanner and pull it out from the plate on the intake mani, if thats all go, we'll go from there...

 

[craigvk]

I just went and checked my car now. I took off the choke pipe you were talking about and it's clean and not clogged. I took the carb hat off and started it up. The choke valve closed as it should but after a minute, the dang choke valve was fully open even though the engine wasn't warm enough. The choke valve is opening too early. :bang:

 

[hispeedvp]

from what i've read im asuming the choke isnt electronic, what travels through that pipe? is it coolant or is it just air? i'de say what evers inside the choke mechanism that senses the temperature needs replacing. you may be able to uprgrade the entire chocke mechanism for an electronic choke wich is definatley the way to go in my opinion

 

[craigvk]

The choke asm is an in and out job. One pipe goes to the in and the other to the out. :bang:

 

[atrail308]

try another heat coil in the choke housing, is there enough tension on it when cold???

 

[craigvk]

Ok. I have two spare carbs here. I will try another one (coil) now.

 

[craigvk]

Dang it. I changed it and it still is crap. :bang:

 

[Tree cutter]

I think your problem could be a blocked vacuum port that is at the top of your choke housing. Take the springy thing off again and then ondo the bolts that hold the choke housing onto the carby body. Next pull the choke housing off to the side and see if you can blow air through the little vacuum hole at the top of the housing. If that is clear try the port in the carby it could be corroded and blocked if it has been sitting around for a while. Once you have that sorted it should be just a matter of turning the springy thing around so the choke stays on long enough. The little vacuum port needs to be open so the choke butterfly opens a bit when you put your foot down on the throttle.