1969 C10 350 engine is bogging at freeway speeds only
 

Hi All,

This is my first post, as my account was just validated. I've already read many post within this forum about bogging though. But I still decided to ask.

I have a 350 engine with Edelbrock 1406 electric choke carb, and it recently started bogging at freeway speeds (55-60+ mph) only. It starts on the first key turn, and drives fine street speeds (30mph).

I recently did the following:

1) Changed the inline fuel filter
2) Bought new points, set them correctly, and installed
3) Bought a new cap and rotor
4) Bought new spark plugs and wires
5) Checked that the fuel pump is working correctly
6) Checked coil and wire connections are getting spark
7) I have a MSD 5 box, and it is still working

I've owned it for about 6 months, but this recently happened.

One problem that I've had since I owned it is the battery will die if I leave the cables connected all night. So there is a short somewhere.

It still boggs after doing actions 1-7 that I listed. I'm thinking about rebuilding the carb, as many have posted 1406 carb issues.

Any ideas?

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

just a guess, but you may have something in fuel line or in the fuel tank that is restricting the fuel..if its below a half a tank of fuel, remove the sending unit and see if the tank is clean or has gunk in it. the fuel sock may have came apart also. you can use a flash light and look inside the tank...hope this helps..good luck on your truck....and welcome to the forum from Texas

we also like lots of pic's lets see your truck....

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

How do you know the fuel pump is good?
Classic fuel pump dieing scenario.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

Could also be the fuel pump push rod is bent or the lobe on the cam that runs the fuel pump push rod is worn.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

Thanks for the replies guys. I will act upon them all as I can.

I believe the fuel pump is good, because I removed the fuel line from the carb and bumped the engine.

The person holding the the container and fuel line I disconnected stated that the gas was flowing good. So I assumed the fuel pump was in working order.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

If it gets worse you'll know it's the pump. You should be able to fill a quart jar in 20 seconds if it's good. Just bumping it won't show much.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

I've had several trucks where the pump will move fuel in the open like this, but it can't push enough pressure (6 - 8 psi for your carb I believe) to feed the engine under load because it's worn down. Mechanical pumps are so cheap it's almost preventative maintenance

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

I had this same issue with my 350 in my 68 c10. I wasn't getting enough fuel pressure. I put a fuel pressure gauge in the line right before it goes into the carb and it was only reading 3 or 4 psi when it should be 7-9. I replaced the electric fuel pump and it fixed it.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

Thanks guys! I've been unable to drive my truck to work this week. However, today I bought a fuel pump, and I can't wait to put it on.

Hopefully this will solve my problem. If it doesn't, at least I know that it's new.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

I just wanted to convey how happy I am, that I've joined this club. Between asking about possibilities when I'm buying parts, and troubleshooting alone, it really brings me down.

I use my truck, and myself to operate a small hauling business. I can't post any pictures right now due to account issues here.

You can see my truck at www.eightyoverhead.com. It's all hands and feet. Just trying to survive.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

You may also want to check timing? Check to see if your distributor got moved while changing things around.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

Hey guys! Got it running again. I adjusted the air and fuel mixture on the carb, changed the line on the PCV valve, and what I believe helped mostly was a product name "Sea Foam", that I purchased at the local auto supply store.

I never heard of it, but it's used to clean carburetors, injectors, etc. when placed in the gas tank. But you have to put it in before you fill up. It must have cleaned whatever that was causing my engine to bog out.

I got on freeway and drove 90 miles round trip to make sure it was fixed. And it didn't bog out one time.

Anyone ever tried "Sea Foam"?

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

Sea Foam is good stuff, I use it all the time just as preventive maintenance

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

good to here its back on the road...ya did good.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

You could experience this problem with old gas (I did on my '70, it gets driven maybe 500 miles a year since I got it, and less before that), but that doesn't seem to be your issue. Guess I'll try SeaFoam in my truck and my Skylark, which also ran like crap after sitting for many months. Gasoline ain't what it used to be.

Re: 1969 C10 350 engine is bogging at freeway speeds only
 

I think I'll continue to use Sea Foam as well. I've owned my truck for only six months, and I've been using 87 at the pump. It's affordable.

With this small ordeal I made it through, I'm considering at least using 89. I want to at least give her better gas. I use my truck mainly as a work horse.

What octane do you guys run usually?