Quadrajet help??

[buckmtn]

Started the truck up the other day. Ran for a few seconds and died. If you dump a little gas in her she'll run that and quit. Pulled the fuel line off and turned the motor over and its pumping gas to the carb. Think maybe the float is stuck or gummed up. Never messed with a truck carb before but have had lots of snowmobile, lawnmower carbs apart. Any ideas? Also the gasket between the carb and intake was broke in half when I took it apart. Took the fuel filter out but it didn't help anything either.

 

[Bent77]

Did you check the fuel strainer in front of the carb? Pull that out, clean it, and run some carb cleaner thru the fuel inlet passage. Since you need a new gasket as well, put a new float and seat in and adjust the float.

Double check the accelerator pump to make sure it is working as well. The rubber diaphram on the bottom can rot.

 

[apache]

You could be seeing fuel delivery but not enough volume or pressure to keep the bowl full. A couple things,fix the bad gasket,replace the filter in the inlet and check your fuel pressure while the lines disconnected. I just parted with a 74K10 that sat around for years moreless. It would not start period unless I used either and or dumped fuel in the carb. I went years starting it like that out of lazyness till I finally found severly cracked rubber fuel lines under the truck everywhere which caused air to get sucked in with fuel,oddly enoght they never really leaked enough see fuel or smell it.
The carbs arent really that tought to rebuild if need be but you will be well served if the tag with the ID number is on it still as theres about 100 different carb kits for the Rottenchesters.

 

[Hogback Fabrication]

Sounds like its time for a rebuild. Its not really too tough, but Q-jets are quite a bit more complex than any snowmobile or lawnmower carb.

Running without a fuel filter for any amount of time is an easy way to clog up a Q-jet, they're very sensitive to any particulates.

Let it soak in a gallon of carburetor cleaner for a day and then blow out all of the passages with compressed air. Replace all of the pieces in the rebuild kit (plus a float) and you should be good to go for $30-60.

 

[buckmtn]

Well I pulled the carb apart bought a rebuild kit put it all back together and still have the same thing. I only pulled the fuel filter out of the original one to see if it helped any, it didn't. It will still fire up if you dump some gas in it but after it runs that little bit it dies. Only other thing I know to do is swap another fuel pump on and see if it helps.

 

[apache]

fire it up again and run it till it dies like usual,then with it dead and the key off look down into the carb and work the linkage full tilt,you should visibly see a steady stream of fuel squrting from the accelerator pump down into the venturis. If theres nothing after doing this a few times then you definatly have a bad fuel pump or delivery issue which is more than likely the pump.