Sbc 350 fuel problems

[Ryanbrown36]

That could make sense as it only runs for 5 mins or so, what’s my best way to check that?

 

[Edelbrock]

Wait....

This could be real simple. It happened to my dad once.

He lost the fuel cap, so he put plastic on the fill tube and rubber banded it in place. The tank created a vacuum and then the engine would starve for fuel. Let it sit for a bit and then it would run again for a few miles than stall out.

A bad cap or plugged vent can do the same thing.

So to test it, just remove the gas cap and try running it again.

 

[Ryanbrown36]

Wait....

This could be real simple. It happened to my dad once.

He lost the fuel cap, so he put plastic on the fill tube and rubber banded it in place. The tank created a vacuum and then the engine would starve for fuel. Let it sit for a bit and then it would run again for a few miles than stall out.

A bad cap or plugged vent can do the same thing.

So to test it, just remove the gas cap and try running it again.

That idea ran through my mind too, I tried blowing air through the lines and selector back to the tank and it’s running now, drove to work today and seems to be fine other than a stubble around 1000rpm but doesn’t die(could be accelerator pump adjustment though) might cut the selector right out of the system even to eliminate potential later problems, and might try to blow out that vent on the tank as well while I’m at it

 

[Ryanbrown36]

Well I got it all going after blowing out the lines and bypassing the selector valve and was able to drive it around for a little bit. I dropped it off at my local speed shop this morning for a quick tune to make sure everything was good and squeeze a bit of power out of it and it drove it home fine and seemed to be running great (other than the stumble around 1000rpm when slowly accelerating) but he was leaving the next day so he only had a few hours to look at it and he normally tries to help me learn and let me do what I’m capable of to save some money. So he said go home and clean the bowls as the fuel that came out looked a bit dirty. After I did that it still had the stumble, cleaned it once more and messed around with vacuum lines making sure there was no leaks and then it died on me again and now will run for a few mins and quit(or not at all) it’s getting fuel now but also gives me the odd backfire, runs very rough, but whenever I check the fuel lines, filter, bowls they are full, very confused again now

 

[Ryanbrown36]

Wait....

This could be real simple. It happened to my dad once.

He lost the fuel cap, so he put plastic on the fill tube and rubber banded it in place. The tank created a vacuum and then the engine would starve for fuel. Let it sit for a bit and then it would run again for a few miles than stall out.

A bad cap or plugged vent can do the same thing.

So to test it, just remove the gas cap and try running it again.

haven’t quite fixed the problem yet but just found that this a what my gas is looking like so think it’s safe to say this has to be at least part of the problem.

 

[Edelbrock]

haven’t quite fixed the problem yet but just found that this a what my gas is looking like so think it’s safe to say this has to be at least part of the problem.

It is surprisingly common. A week or two back, the same issues was discovered through this forum on someone's truck.

A few days ago I picked up a non-running small engine. The fuel was half water. Replaced the fuel and its good to go.