Open the secondary barrels!! Please?! Need POWER

[83RustyRed]

Hi there, I'm new to the board, posted an intro there. My issue is that I stall out and miss when trying to really get her ass going. If I'm realllly gentle with the throttle, she's fine. When I actually put my foot on it, especially Uphill, from a stop, yech! Can we get to 35 today? I don't mind, but eventually, I need to get into the mountains and climb some serious hills, preferably over 45 mph.

I've got a rochester 4 barrel qjet on my 83 c20, and from what I can tell, those barrels aint opening when I stomp on it. Engine revs as high as I want in neutral, but under load, i just cant get any real power! It did sit for quite a while, been trying to run lucas fuel cleaner with 89 octane thru the left hand tank to clean it out, just taking forever, if it's still the dirty old gas...Or maybe its this carb? Already changed one fuel filter, and I did hit 80 for 20-30 miles, and it was fine. The next day, it couldnt maintain 65 or accelerate to 70 without cuttin out. Maybe another 7$ filter? got a back up OEM carb to learn how to rebuild, so I don't mind one way or the other...

For giggles and poops, heres some pictures of the carb. Im thinking theres a diaphragm vacuum that needs to be connected to the right place. What is that? Definitley moves those secondaries...


??? Any help appreciated. Thanks!

 

[89Suburban]

Yeah, Vacuum secondaries. They only open according to the load on the engine. Been years since I messed with them. Some others will chime in on this I am sure.
I take it you don't have a vacuum diagram label on your radiator support?

 

[89Suburban]

Here is some generic vacuum diagrams, need an account on Autozone's site to view I think:

http://www.autozone.com/autozone/re...epairGuideContent.jsp?pageId=0900c1528004c3cb

 

[83RustyRed]

nope, no diagram, and no autozone membership yet.

 

[wheelerboy12]

nope, no diagram, and no autozone membership yet.

r

well theres your problem no autozone membership, they come in handy, sometimes getting you a discount, and every 100 bucks you spend there you get 20 free haha, ive already worked up to 40 free bucks, close to 60!, as for your carb issues id look into your vacume's (i know i didnt spell it right but its late and i tried 10 times lol i give up ) also i would get rid of the qjet filter and just get an inline AC delco filter. they are much better.

 

[Irishman999]

I responded to your introduction post in reference to the vacuum pod for the secondaries. If the truck has been sitting a while, long enough for fuel to go bad that could be the cause of your problems. I battled the same ******** with my truck, old fuel will cause some major headaches.

When I first got my truck I rebuilt the carb, ran the truck for a while and the carb just got gummed up again. Shortly after the thing started backfiring through the carb and dropping cylinders. I pulled the valve covers and found that 3 intake valves had broken pushrods. This was caused by the gummy nasty fuel getting on the valves and causing them to stick in the valves and and break pushrods. When it started the first time I had all 8 cylinders so I know it was the old fuel.

My point is before you rebuild a carb you might look into draining the tank and filling it with fresh fuel.

 

[83RustyRed]

Thanks, yeah i figured that would be a pain in the ass. It was barely over E when I bought it, so i think its just a lot of old sludge on the sides or something. She runs a lot better with a full tank, so that just pinpoints it even more i think.