350 Never seen one do this

[HAULIN IT]

Hook the vacuum gauge to an intake vacuum port and route the gauge up to the windshield. Duct tape it to the windshield and put the truck in gear. Accelerate to WOT and observe the vacuum gauge. It should drop to zero and rise. If it stays at zero suspect a plugged exhaust.

Vile, I have to say I've never heard or seen the "and rise" part. How long are you expecting it to take to start rising? How high would/could it rise? Lorne

[Dr_Snooz]

x4 on exhaust restriction.

[spectreblazer]

x4 on exhaust restriction.

i don't think it is the exhaust. this truck is reallly loud and has a ton of exhaust. it has duals

[1980c10]

I'm with zeig85 on the fuel restriction. I would replace the fuel filter and test fuel pressure. Also check the condition of your spark plugs, black and sooty means your are running rich, clean and dry and white means you have a lean fuel condition. At a minimum check one on each bank and check them all if you want to see if you have a particular problem on one cylinder. 

[1979C20]

Just curious, kind of odd question. Where you live? There was a bog event I went to last night

[spectreblazer]

spark plugs were changed last summer. i will change that fuel filter though if it has one. it was a 6.2L before so it had the water separator/fuel filter in one and it is gone now.

MI

it was mud bogged awhile back. right before winter. so it was in the fall

[1980c10]

spark plugs were changed last summer. i will change that fuel filter though if it has one. it was a 6.2L before so it had the water separator/fuel filter in one and it is gone now.

MI

it was mud bogged awhile back. right before winter. so it was in the fall

You don't need to inspect your spark plugs for wear, you would inspect them for color, this tells you if you are running rich or lean or even a correct a/f mixture, regardless of if they were changed in the summer you should inspect them with your current issue.
white=lean fuel condition
med brown=correct
black=rich fuel condition
an individual plug that is darker than the rest could indicate a problem with that particular cylinder.
report your findings back here and someone here can point you in the right direction.
also you should have a fuel filter in your carb.

[VileZambonie]

Hook the vacuum gauge to an intake vacuum port and route the gauge up to the windshield. Duct tape it to the windshield and put the truck in gear. Accelerate to WOT and observe the vacuum gauge. It should drop to zero and rise. If it stays at zero suspect a plugged exhaust.

Vile, I have to say I've never heard or seen the "and rise" part. How long are you expecting it to take to start rising? How high would/could it rise? Lorne

Good catch Lorne! I think I was half in the bag when I wrote that. A much needed night of drinking lol - The truck should NOT be in gear it should be in Park or Neutral.

[spectreblazer]

i'll check the spark plugs out when i get some time on the weekend guys. anyone know where the fuel filter would be on a quadrajet-4 barrel carb?

[Lt.Del]

yes, it is cylindrical shaped and is located right where the gas line meets the front of the carb.



mine is a little different at the front, but, look at this vid, be careful of the spring..


http://www.youtube.com/watch?v=WK0sqMI6mMs

[1980c10]

btw; when you change the filter be sure to check for leaks