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| | | 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | I have a '71 Chevy G10 and it was running great up until today, I recently had some work done and the carb and fuel system was cleaned and checked. Issue started with hesitation when going up a hill. My fuel gauge is stuck at 1/4 so I thought it might be gas so filled it all the way up for the first time (almost 20 gallons). This produced a steady drip of fuel coming from front middle of gas tank. I thought maybe one of the top hoses was leaking so drove it to try to burn off some gas. After about 15 miles carb got flooded and shut off engine, and it wouldn't restart. I let it sit and pushed down flaps to let fuel drain, cranked it without pushing gas pedal and after about 10-15 seconds it started and I drove it a few miles home, where it coasted to a stop and died. From my observations this is what I know: -Fuel gauge doesn't work so maybe tank float is stuck or malfunctioning -Gas cap gasket is done and not much of a seal -There is one single wire sensor on the front driver side of the carb, not connected -Carb is clean and flaps move, and I see fuel squirting in when I push on gas and push on lower flaps
Any help, please? | | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | SO I let it sit for an hour or two and when I checked it was still leaking from above the fuel tank. I popped off the gas cap and the fuel hose at the fuel filter and drained about a gallon out then reconnected the hose. Leak was still happening so pulled it onto the grass to let it sit for the night. I don't know much about carb vehicles but I don't understand why fuel would be coming out of the feed hose when it's turned off. I believe the fuel pump is in the back passenger corner, and it was not pumping. Any suggestions what to check next? | | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Jul 2016 Posts: 96 journeyman | journeyman Joined: Jul 2016 Posts: 96 | a 71 will have the fuel pump on the engine block unless someone added an electric one or something.
1979 Nomad 2005 E350 Cutaway Class C
| | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | I'll have to check. Does the fuel pump prime before starting or is there always fuel in the line? | | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | Yes, you are correct, there is a fuel pump on passenger side of engine. The fuel feed line should not have any pressure while sitting, correct? I'm checking to see if there is a return or vent line, or if maybe it's blocked. Even if there was no return line I would think that removing gas cap would release any pressure. By chance is the top of the fuel tank above the level of the fuel hard line (van is lowered)? Even if it had slight pressure from gravity I don't see how that alone would cause fuel to flood it. To be honest I don't understand older car stuff like carbs. Still reading up on it but don't know how the carb adjusts the air / fuel mixture. If it means anything, when fuel dumps into the carb from the two squirters it is more of a small stream and not a spray. | | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | Messed around with it yesterday and thought I had fixed the issue. It drove great for about 10 miles then while accelerating it instantly stalled out. Tried to turn it over a bunch and a couple times it wanted to start then nothing after that. To be honest I am not even 100% sure my issue is flooding, It's just my best guess. I have the manual but what I have does not match up totally to what is in the manual, so I'm sure some things have been changed or modified from stock. I discovered the fuel leak issue was the one feed hose from tank was falling apart and fuel was getting siphoned from the tank while sitting, allowing it to leak. I'm hoping there is an access panel above fuel tank so I don't have to drop it to replace hoses.
The van does have the stock style fuel pump, and the hard line going in. I can't find a fuel return line, and there is an open hard line on passenger side, and an open nipple on front of carb. I'm guessing they go together. The air intake does not have the large hose going from engine to vacuum flap inside air cleaner, and I don't see anywhere that it would come from. I found a loose yellow wire and connected it to sensor on front of carb. I don't believe I have any emissions there is no charcoal canister, but there are a couple vacuum valves and I think a magnetic valve (flying saucer) with lines. There are also a few capped vacuum nipples.
I think I'm just gonna tow it to the shop and let them deal with it. I need to learn more about carb diagnosis (it's supposed to be easy right?) but just don't have the time right now.
Last edited by discountpirate; October 10th 2017 2:06 pm.
| | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | I'm thinking that some things on my engine have been swapped from the way it was set up stock. Since I don't know exactly what I have I can't find diagrams to see how it should be set up properly. I know the distributor has been switched to HEI. I have some kind of long tube aftermarket headers. I believe that my intake manifold, carburetor and air cleaner are not stock. I'll see if I can get some pics to post. | | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | After a bunch of tinkering I think my issue is probably ignition related. It's definitely getting gas, and I will get it running fine and then in the middle of driving it just dies. I also learned that a lot of the previous stuff I was trying to figure out isn't necessary for it to start and run. I previously had an issue years ago where my ignition cylinder was loose and twisting and the pink wire on back popped off, it would turn over but not start. I checked the wire and it has contact but the cylinder itself is loose so gonna start off by switching ignition cylinder and checking wiring and see if that works. | | | Re: 1971 Chevy Sportvan- Flooded Carb Issue | Joined: Feb 2014 Posts: 63 journeyman | OP journeyman Joined: Feb 2014 Posts: 63 | Well, I guess I'm not as retarded as I thought, I was able to finally figured it out. I was checking the ignition wiring and when I got to the HEI connecting I discovered it was just a crimp on connector and did not attach in place, so it had slowly worked it's way off over time causing the intermittent issues. Now back to business. The two questions I have left after all this is: The HEI has a connection for "tach", can I connect any tachometer to it or does it have be a certain type? I still have to properly fix the fuel line fro the tank, is there an access panel or do I have to drop the tank (currently has wood and carpet on floor)? | | |
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