Broken hearted kid and fuel system

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Dryriver1

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Robert
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1984 Chevy Silverado K10, 1999 Chevy 2 door Tahoe 4x4
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350 cid, 5.7
This is the weirdest **** I’ve ever experienced in my life. Ok so, went and got the clamps and things to run directly from the fuel tank. I hooked the supply line (the big one) up to the fuel tank and then directly to the fuel pump. Then from the fuel pump (now the threaded one) to the front of the carb. Tried starting it and nothing. I disconnected it and a little fuel spit out and damn if the truck didn’t start the truck was running without the fuel supply line attached. I’ve got to find a way to add videos cuz I can’t believe it. There was no fuel coming from the supply line Just a bunch of smoke from the exhaust and some silver pipe on the left side. As long as he kept his foot on the throttle, it kept running. Soon as he took it off, it would cut off. Then he had to play with it a little bit and it would start right back up. How does a truck run without the fuel line attached?
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You have that question how can it run with the fuel line off.

There is a small amount of gas left in the carb where the float reservoir is.
It will not run for a long time but it has a small amount of gas left there.

Like many have said "Don't give up!
It is not rocket science."

You guys can do it! Just a process of elimination and you will find it. Do like Everyone here told me also "Don't just throw money on it. Diagnose and find what the problem is."

Everyone here has been a lot of help to me also!

Keep us posted.

R.
Dryriver1
 

Travlr

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C
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K20 Camper Special
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Ok yall, Ive got a situation and I cannot figure it out. I am not a mechanic by no means but hoping someone here can point me in the right direction. My son was gifted a 1984 Chevy K10 with a 350 motor by his grandfather. For those that work at a parts store, yes its four wheel drive. It has the regular quadrajet carburetor on it. The problem is, we cannot get gas into the carburetor and I cannot figure out why. We have been working on this thing for months and each time we discover something new, he gets excited because we finally think we have found the problem. We fix the issue, and it still doesnt work. Last night we worked for three hours just to try to start it til the battery died. He just hung his head and started crying and its killing me. I love working with him on it to help him restore it but im also tired of throwing time and money at something and getting nowhere. Fuel is not getting into the carburetor and i cannot figure out why. His grandfather said it ran before, it just needed the carburetor cleaned because it had been sitting for about 7 years and the fuel tank selector switch needed replacing. Here is a list of everything we have done.

- When he first got the truck, the carburetor was taken off and given to a mechanic to clean. He cleaned it and did a few other things to it and we got it back. Wouldn't work.
- bought and installed a new fuel tank selector switch, didnt work.
- dropped the passengers side tank and cleaned it out, put in a new fuel sending unit. didnt work
- Bought a new mechanical fuel pump for it and put it on, it ran for 4 minutes and then didnt work. There was fuel in the pump when we removed it.
- Bought new spark plugs and wires, didnt work.
- Found out my son didnt get all of the water out of the gas tank before the tank was put back on so we dropped it again cleaned it again and got ALL water out. It was dry as a bone. Replaced everything and filled with gas, ran for 2 minutes, wouldnt start.
- Bought a new mechanical fuel pump just in case water messed up the first one, still didnt work. There was a little fuel in the pump when I removed it.
- Ran a line from the carb to a bottle of fuel, works fine.
- Blew air through all the lines and there was no fuel anywhere. I couldn't hear any leaks, but there was no fuel when I moved my finger off the hose and I felt the air.
- just in case, all rubber fuel lines were replaced. still didnt work.
- Tried the bottle thing again, ran fine. However, no fuel in the lines that I could see.
- Replaced the tank selector valve, no gas anywhere, still wouldnt start
- Checked the rotor cap and its clean and replaced just as it was. Ran fine off a bottle.
- Found out about a push rod that makes the fuel pump work (had never heard of this before) but went and bought a new one. When we pulled the fuel pump off, I there was one already in there and I could tell that at the bottom of the arm on the back where the rod had been hitting it at the tip. So Im assuming that is working properly.
- Last night we replaced the metal fuel line with a rubber one on the front of the motor. That is literally the only part of the fuel system left that had no been replaced (except for the metal lines) on the passengers side. Still wont start.

Just for ***** and giggles last night, I read about priming the carb. We poured a total of an entire 20 ounce bottle of gas down the carb choke side and it would run until the gas was burned and then cut off. We tried starting it until the battery died and when it died, so did our ambition.

So, what else could it be that is causing the fuel not to get into the carburetor. I did pull the fuel filter last night and it was pretty clean, there were some black dust looking things on it but otherwise it was clean. It had fuel on it but not as much as I imagined it should be. The check valve was installed on the nut side of the carb. Is that backwards? What am I missing? Just an FYI, all of the work was done on the passengers side. We have not touched the drivers side. We wanted to get one tank working and then focus on the other one. Could that be the problem? I am so tired of throwing time and money into this thing and not getting any results. I only have 3 months until he gets his license and I dont have a lot of time to work on it. Someone please help!!!!
So is there an update @medic503 ? Have we been abandoned to wander through eternity wondering if your kid ever got to drive his truck?
 

jlynn79

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Hey y'all, I am medic503's son. I am the heartbroken one. lol. He has been really busy with work and stuff and hasn't really had time to get on here and update everyone so, Here is a small update. We have determined the carb, fuel pump, and engine are not the problems. lol. When we connect the fuel pump directly to a gas tank it runs fine. The problem comes when we connect it back to the factory fuel lines. As soon as we do, the truck cuts off and will not run. It will start and idle but that's it. As soon as we hit the throttle, it just cuts off. However, when it is connected to the gas can, it runs and throttles fine. We are going back on Friday to see if we can figure out anything new. We are going to try to take the bed off and see if we can find any kinks in the lines. Anyone have a diagram of the plumbing of the fuel selector valve? The one we have has 6 ports, two on one side and four on the other. I want to make sure that is pulmbed right as well. We put the carb supply line in a bottle and cranked the truck and the only thing it did was pulsate air and a very little bit of fuel. I think I could have spit more than the fuel that came out. We just can't figure out where the kink is.

Another thing. While I was under there the other day, I noticed there was a purple wire hanging that had been cut. If this wire is not connected, will it cause it not to work? I see that others have the little plug thing on top of them but there is only one wire for ours and it is a ground wire. Does the ground have to be in a certain place or does it go anywhere on the frame? Is there an actual electrical component on the fuel sending unit that we should hear when the ignition is turned on?

I am getting aggravated because it idles fine, but as soon as I hit the throttle, it cuts off. Daddy told me about the left over fuel in the carb after it turns off. Hopefully, after this Friday we will be able to say it runs. I will update everyone Friday night or Saturday morning as to how things go. Thank you all for your quick replies. I will continue this thread until we find a solution and the problem is fixed and I can post a video of his truck not only idling, but actually running. Again, thank you all so much. I really appreciate all the replies.
 
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JamesSam

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Yeah I really want to know. I am following this thread and sitting on the edge of my seat. One of the next projects for my truck is the fuel system. I currently only run on passenger side. When I got my truck I could switch tanks but one day all power to the truck stopped while on the driver's tank. I switched back to passenger and drive home. I still have not figured out if it was the selector valve, the fuel pump, rusted lines, water in the tank but have somewhat tried troubleshooting and getting baffled. I swear fuel transferred between tanks during the troubleshooting...anyway...I really want to see success here and am soaking it all in. Also, my truck is an 87 so TBI in the mix with it.
 

jlynn79

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K10 Silverado
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5.0 Liter V8
Yeah I really want to know. I am following this thread and sitting on the edge of my seat. One of the next projects for my truck is the fuel system. I currently only run on passenger side. When I got my truck I could switch tanks but one day all power to the truck stopped while on the driver's tank. I switched back to passenger and drive home. I still have not figured out if it was the selector valve, the fuel pump, rusted lines, water in the tank but have somewhat tried troubleshooting and getting baffled. I swear fuel transferred between tanks during the troubleshooting...anyway...I really want to see success here and am soaking it all in. Also, my truck is an 87 so TBI in the mix with it.
My daddy he wouldn't die until he made sure that the truck was running and running right. He's kinda old so he don't got long but me and him both want to get it running. He read through a bunch of threads that just ended and never gave causes/results and he would get so mad. So, we're gonna get this done. Friday were gonna take some pics of everything and try to get videos of the issues at hand and go from there. But, this issue will be resolved and this thread updated completely until it is. Looking forward to more ideas and more problems. Daddy hates it but I like it.
 

Turbo4whl

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@jlynn79 Hi James, with the info you and your dad posted, you have located the problem. Most likely the line is not kinked.

Since the truck sat for some time, 7 years quoted, the old fuel left in the steel line dried. What is left is a sticky goo. Trying to draw fuel through drags some rust crud from the tank and will clog the steel line.

You can try to blow the crud out, but most likely you will need to replace the steel line. NAPA and others sell nickle metal line that you can bend by hand or use a bending tool for some cleaner tight bends.

If you bypass the tank selector for now, short rubber hose from the tank pick up to the new metal line and again at the fuel pump. Then you will be up and running! Fix the tank selector later.
 

Radiohead

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You can get a barbed union to connect the hose from a tank to the hose connecting the steel going forward and bypass the valve altogether. Don't forget that the return line needs the same treatment, so two barbed unions appropriately sized with clamps and there you go. All accomplished at the selector valve and if secured well, near permanent bypass to the problem.

Using something like this, I remember them being brass back in the day.
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D'oh, forgot about your steel line being plugged.
 
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Turbo4whl

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Just run your new metal line right to one tank. Use rubber hose to connect to the tank sender. 3/8" hose and 3/8" metal tube. Two mini worm drive hose clamps. Run the metal tube right next to the original for now and connect it to the fuel pump. Use some ty-wraps to hold it. This is temporary so you can move forward with you restoration. More permanent, the metal tube should be clamped to the frame like the original.

Later you can get the tank selector issue fixed.
 

jlynn79

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Ok. We will try that. Before we do it, is it possible to just jack up one side of the bed? Like take the bolts and wires apart and just jack it up? I don't have a cherry picker or any kind of lift nor do we have enough people to get together at one time. But, if we can just jack one side up enough to see and get some working room, I think that would work. I just want to make sure it's not going to mess up the other side if we leave the bolts in. Im not trying to create more work down the road.
 

Turbo4whl

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You need to remove all the bed bolts, then you can jack one side up some. If you only unbolt one side you will bend metal. Here in the rust belt bed bolts do not unbolt well. The carriage bolts spin in their pockets. Some bolts you can lock vise grips on the bolt shank, but not all.

Usually easier, is to drop the tank.
 

jlynn79

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You need to remove all the bed bolts, then you can jack one side up some. If you only unbolt one side you will bend metal. Here in the rust belt bed bolts do not unbolt well. The carriage bolts spin in their pockets. Some bolts you can lock vise grips on the bolt shank, but not all.

Usually easier, is to drop the tank.
That makes sense. As many times as we've dropped it and put it back, we can do it with our eyes closed. thanks for the insight. You just saved us many hours of frustration and him cussing. lol
 

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