Help! no acceleration/power up hills

[doodah man]

Hello all,

This is my first post on the forum. I just bought a 1972 C-10 about 2 weeks ago with a 350 V8 and auto transmission.

It runs down the hwy really smooth but won't accelerate when I go up a hill from a stop or low speed. When I give it more gas it feels like it's going to stall, so I let up on the gas pedal and let it accelerate slowly until I'm up the hill. The two times this happened the engine was cold. It doesn't sputter on flat roads when I accelerate, but not doesn't have as much power as I'm used to from driving trucks with newer fuel injected V8s. I haven't tested its performance up a hill when the engine is warm.

One last piece of information that might be useful: I bought the truck at an estate auction and it has only rarely been driven in the last 20 years (almost never in the last 4). I've driven it about 150 miles since the purchase.

I'm going to replace the fuel filter and check/change the spark plugs. I will also spray some carburetor cleaner in the carb. Any advice if neither of these fixes the problem?

Thanks in advance for your help. This is my first old truck and my first carburetor-fed engine.

[cdowns]

if it is a quadrajet carb there is a fuel filter in the body of the carb

does it have the original points type distributor? if so clean and set the dwell for the points

[JORGIE95961]

not downshifting, try to manualy shift from a stop going uphil down to first gear

[Keller]

its probably a combination of issues. give it a good tuneup. spark plugs, filters, points, timing, etc... also, let it warm up before testing. i know my truck runs a lot better when she's warm. it's almost like it doesn't want to really go fast until she hits about 190 degrees.

[68gmsee]

Agee with above suggestions. And definitley could be several things from simple filter replacement to bad cam.

If you didn't drain the old fuel and cleaned the tank you may be having problems with rust and varnish build up in the tank. Since you've been running it like this it's possible it may just be messed up filters or the carb fuel bowl. Start with the easy ones like filters.

Here's a quick list of what I'm doing on my 69 truck that's been sitting for 5 years.

Check all rubber hoses for cracks and leaks

Replace plugs, points, dis cap and rotor and plug wires

Adj timing after engine replacement.

Insure the vacuum advance is working properly and not leaking (you can use mouth suction to check it)

Check fuel pump output by removing dist to coil wire, remove line at carb and place in a plastic jug, crank the engine. Should get app 1 pint of fuel in 30 seconds or less)

Remove old gas, clean tank or replace it

[white 67]

I had a problem like this once and it turned out to be a piece of paper in my gas tank that had come apart and got past the filter into the carb. I didnt find it until i replaced the tank.

[doodah man]

Thanks for the advice. I'll be looking into these questions this week and report back.

[DevilDog Aggie]

Hey there. I know it has been a while since you dealt with this issue. I'm new here and just bought a '72 C-10. It is having the same issues. I need to get it running somewhat reliably before I get started on anything else. I am going to do a full tune up this weekend, but wondered what you found to be the solution.

Thanks!

Rob