Accidently left the fuel hose on top of the carburetor and gas poured into the carburetor, will not start

DUSTIN BOBO

MEMBER
1993 GMC SUBURBAN
5.7L
V8
4WD
AUTOMATIC
240,000 MILES

There other day I broke down in the middle of the road after I gassed it to get around someone. My trucked made the pass then sputtered and shut off. I was not able to get it to crank back up and drained the battery trying to do so. So my son comes to help me at least tow it off to the side of the road and there we tinker around and find the problem. We disconnect the fuel line from the carburetor (yes, I took the tbi off and replaced it with a nice 2 barrel Holley) and he had me turn on the ignition and no fuel, so now we know it's the fuel pump. So, fast forward about two hours and we got my truck hooked up to chains behind his truck ready to pull me home. About half way the chains come unhooked and we pull to the side of the road were we noticed gas just pouring out from the bottom of my truck. I snapped and ran and turned off my ignition. Seems that during the tow the fuel pump decided to work after all. Unfortunately we had left the fuel hose just hanging inside the top of the carburetor. Next morning first thing I change my oil, which is now about 5 quarts oil and 5 quarts gas, and try to crank it up but the starter just goes boom like it's stuck. We were able to manually turn fly wheel as well as make all the pulleys under the belt turn. Not sure what is wrong or what actions I need to take next. Please help.

2 Replies

KASEKENNY

MECHANIC
18,907 POSTS

At this point you need to replace the starter and pull the spark plugs and crank the engine. Hopefully there is no damage done to the crank or flex plate but we will know that when you crank it with the plugs out.

What happens is when you flood the engine like you did, the combustion chambers become full of fuel and it drains down into the pan. Liquid does not compress so the weakest point is the starter when you try to crank the engine. It is called hydro locking. Removing the spark plugs will allow the pistons to blow the fuel out of the spark plug hole and it should start again. Clearly I would replace the plugs as they are surely fouled now. Then just make sure you remove the plugs and wires or disable the spark because you don't want any chance of arching as it will be spraying fuel out at a high velocity.

Then let the engine air out for a couple hours and then install the new plugs.

Let me know what questions you have and we can go from there.