350 SBC Pops and Dies When Put in Gear

[zghorner]

I just repossessed a 1980 Chevy 3/4 ton and have been trying to get it running decent before listing for sale. It has sat for several years and definitely more of a project than I am interested in. It will idle just fine and rev up in park with no issue but as soon as you put it in any gear it bogs down and pops then dies when you give it gas. I can feather the throttle up to maybe 5 mph but that's about it before it craps out.

I have fixed several major vacuum leaks with no change in how it runs. Plugs and wires are good, timing is good, gas is good. I poured about 10 oz of marvel mystery oil down the carb while it was running and let it soak for a week...no change.

it has a 4bbl quadrajet and turbo 400 trans.

any ideas?

 

[Okie4570]

Checked the small screen on the front side of the qjet to see if it's clean?

 

[zghorner]

Checked the small screen on the front side of the qjet to see if it's clean?

I put a new fuel filter in it if that’s what you are talking about and verified that the pump is putting out plenty of fuel.

 

[Okie4570]

There's a small filter/screen about the size of a pencil on the front.

 

[Okie4570]

They're somewhat popular for off-road guys because you can run them straight up and down or nearly on it's side without issue like most carbs. I've got one on my 71' bronco. I've run into a couple others that had power issues would die when that screen is plugged. Will still idle fine of course.

 

[zghorner]

They're somewhat popular for off-road guys because you can run them straight up and down or nearly on it's side without issue like most carbs. I've got one on my 71' bronco. I've run into a couple others that had power issues would die when that screen is plugged. Will still idle fine of course.

I’ll check it out thanks.

 

[okcBob]

Learn something new every day

 

[Snattlerake]

Cat plugged? Is there an old O2 sensor? It does sound fuel related. Back in the 60's it could have been a carburetor accelerator pump diaphragm pinhole.

 

[Aries]

I had an '82 F150 that did something similar but not exactly the same... would run okay at slower speeds, but by the time you got up to 60 mph it was cutting out and sometimes would die. Turned out to be a rubber fuel line that got so old and soft it would collapse when the carb really started pulling gas, and cut off the fuel supply.

Also wondering if there's any chance it could be a collapsed exhaust pipe?

 

[RangerRick]

Sounds like a tranny issue to me