Power loss with aggressive acceleration

[Brownie82C10]

My 1982 Chevy C10 (six-cylinder engine) is old and tired. The engine doesn't stall with aggressive acceleration from a start, but there is a very noticeable drop in power. The truck accelerates fine — cold or warm — as long as I ease through all the gears (with automatic transmission) and don't push the pedal to the metal.

It's been a number of years since all the plugs, wires and distributor cap were changed.

Where should I begin with an engine analysis?

Thank you.

 

[fast 99]

sounds like a possible lean condition fuel supply or carb

 

[Edelbrock]

Might be using up the fuel in the carb faster than it can be replenished. A way to test, would be to to fill the car through the vent and then pin it to win it. If that solves the problems at first, but the problem returns, then I would clean the carb and replace the fuel filters. Also, try removing the gas cap as a test, in case the vent is partially plugged. If you have a manual choke, that may also help diagnose the issue.

 

[Brownie82C10]

Thank you, Edelbrock and fast 99. I did replace the gas cap about a year ago. If I recall correctly, I started noticing the issue not too long afterward. Also, I park my truck in my garage nightly. (It's my daily driver.) Gasoline fumes are noticeable, but there's no signs of a fuel leak.

 

[Brownie82C10]

Well, the problem doesn't seem to be related to the gas cap. I swapped it out with no change. I even drove home from work once with the cap off. The hesitation when I floor the pedal persists. This usually is in first and second gear. Once I've gotten into third gear and up to speed, there's no hesitation when I speed up.

 

[75gmck25]

What type of carburetor is on the 6 cylinder?

When a 4 barrel has this type of symptom you would usually check to make sure the secondaries are working and properly kicking in, but I thought the 6 cylinder used a two barrel carburetor. The other items to check is the float level and the fuel filter. It may just be running short of fuel.

 

[Brownie82C10]

It's a two-barrel carb, 75gmck25.

 

[Edelbrock]

You can get a brand new carb for under $100 with free next day shipping.
Then you could bolt it on and see if that solves the problem.
If the problem is fixed, keep the carb.
If the problem remains, return the carb free of charge.

They can be found on Amazon.