65 chevy with a 292 fuel problems

Mrbeans

Newbie
Joined
Jul 26, 2008
Messages
5
Points
0
have a 65 Chevy stepside it seems to not be getting any gas as it runs really ruff when you try to give it some gas, it will idle fine but as soon as you put your foot in it a bit to take off it starts cutting out and lurching horribly have blown all the fuel lines and replaced the fuel pump and still have same problem. would appreciate any ideas as i am fresh out oh and i also just rebuilt the carburetor
 

Jim Fairbanks

wrench
Joined
Nov 17, 2006
Messages
4,508
Points
38
Location
Portland,Oregon
Did you replace the accelerator pump in the carb?...Sounds like it might be bad or the inside of the carb where it sits might be rough..letting the gas go around the rubber on the accelerator pump.....Jim
 

Mrbeans

Newbie
Joined
Jul 26, 2008
Messages
5
Points
0
Honestly don't know its a single barrel Rochester carb and we put a carb rebuild kit in it. unless the pump is a small rod with a rubber bushing on it. then yes we did. I say we as I had a friend help who is more familiar with carburetors than i am
 

Jim Fairbanks

wrench
Joined
Nov 17, 2006
Messages
4,508
Points
38
Location
Portland,Oregon
Yes..the small rod with the rubber on it and a spring..sometimes the bore that it sits in gets rough and needs to be smoothed out.You said it idles OK..When you take off and give it gas, does it go better if you accelerate slow?...And fall on it's face if you accelerate faster?...Jim
 

Mrbeans

Newbie
Joined
Jul 26, 2008
Messages
5
Points
0
No it does not seem to matter. if i keep giving it gas it will eventually smooth out briefly then it starts sputtering and backfiring, and when i give it gas slow or fast it makes a horrible sucking sound. the only thing i haven't replaced is the pcv valve and a buddy told me that it would not cause this type of problems. I pulled the plugs and they were quite dirty so i cleaned them up and put them back in but no change in problem.
 

Jim Fairbanks

wrench
Joined
Nov 17, 2006
Messages
4,508
Points
38
Location
Portland,Oregon
Have you done a fuel pressure test on it?....it should be about 31/2-41/2 psi...there might be a hole in one of the fuel lines if it is low,since you put a new pump on it...Jim
 

tombtomb

Sr. Member
Joined
Nov 21, 2006
Messages
160
Points
16
Have you checked all the basics? With fuel line disconnected from carb does it pump plenty fuel ? Will it run better if you partially choke it? Is there a good spark when you rev it with the vaccum advance disconnected ? By the way as a footnote I used to have trouble discerning a 292 from a 250. But if you look straight down onto the engine & the motor mounts are directly across from one another then it's a 250 or 230. If the mounts are slightly staggered, not even, then it is a 292.
 

Connie

FISH ON!!!!!!!
Joined
Nov 14, 2006
Messages
863
Points
16
Age
121
Location
Centralia, WA
choke sticking..... vaccuum advance messed up.... but I would almost bet your choke is sticking. Disconnect it and see if it helps. It will run rough until it gets warm but make sure it is all the way open when disconnected
 

NickD

wrench
Joined
Aug 28, 2007
Messages
5,232
Points
48
Just once in my life, rebuilt a carb where the act of sliding on the fuel line was a sharp edge on the carb nipple that was peeling off bits of the neoprene inside of the fuel line plugging up the main jets. This was after the fuel filter on this thing. Had that carb off twice before finally realizing what was going on. Third time, filed off that sharp edge and all was okay. Just saying, it doesn't take very much, those find subtle details.

Did you do a compression test? Maybe the carb isn't even your problem, they don't work worth a darn unless you have sufficient manifold vacuum. Also vacuum leaks can cause these kinds of problems, power brakes? With a carb, either too much or not enough fuel can give you headaches. Are you seeing fuel at the base of the intake manifold? You can smell it.

Man, those engines were simple compared to what we have today, but really hated heat risers, a pain to change, a closed heat riser could burn up a carb quicker than you could shake a stick at it. Also a vehicle that old can have a rusted up fuel system, heck they were rusted up when only a couple of years old. GM rust, we called it.
 

Mrbeans

Newbie
Joined
Jul 26, 2008
Messages
5
Points
0
Ok I think I have narrowed it down to the accelerator pump not working correctly is there anyway to fix this. I just put in a complete carb kit. yet the accelerator pump does not move as easily as you would think it should is it the springs or has this 43 year carburetor just finally had enough. I do work in a machine shop would it be possible to hone the cylinder that the accelerator pump goes into or would this cause to much gap for it. Once again I appreciate any and all suggestions.
 

tombtomb

Sr. Member
Joined
Nov 21, 2006
Messages
160
Points
16
Did U install the spring beneath the pump piston ? Sometimes these pumps won't work because the little steel check ball is not seating properly. To seat it tap it down into it's seat lightly using a drift punch & ball peen hammer. Also did you order the kit by the number stamped into the carb housing ? If you odered it by vehichle application the rubber seal on the piston could well be too large as this might not be the truck's original carb. Always order carb parts using the number stamped into the housing.
 
Top