Is this a small block or big block engine?

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Ewhitaker0020

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My 1980 which is also a k25 with a 350 also has a 3 line fuel pump.

More than likely I just missed a hose then. Tomorrow I'll actually crawl under the truck to check. I may replace the pump regardless just to have one less thing to worry about. They're only $20 and I'm sure it's the same pump for at least 20 years.
 

AuroraGirl

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More than likely I just missed a hose then. Tomorrow I'll actually crawl under the truck to check. I may replace the pump regardless just to have one less thing to worry about. They're only $20 and I'm sure it's the same pump for at least 20 years.
thats not to say the motor wasnt swapped and the donor engine had only 2 lines so one was not-reused, not realizing they are not creating a pressure issue which could cause driveability issues like hesitation, heat soak, etc.

but a great way tofind out, look by your gas tank and see if three rubber lines make their way to the tank, and look at pump. should be a hard metal line that runs along with the fuel line and it goes most of the wya to the tank where it becomes rubber fuel line again.

here an example off google i think

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Ewhitaker0020

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thats not to say the motor wasnt swapped and the donor engine had only 2 lines so one was not-reused, not realizing they are not creating a pressure issue which could cause driveability issues like hesitation, heat soak, etc.

but a great way tofind out, look by your gas tank and see if three rubber lines make their way to the tank, and look at pump. should be a hard metal line that runs along with the fuel line and it goes most of the wya to the tank where it becomes rubber fuel line again.

here an example off google i think

You must be registered for see images attach
The truck has a dump bed, so it'll be easy to see the tank.

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Ewhitaker0020

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The verdict is in. I have a small block and a 2 line fuel pump. Thanks for the help everybody.
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Bextreme04

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The verdict is in. I have a small block and a 2 line fuel pump. Thanks for the help everybody.
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Yep! That's not to say that it is supposed to though. I would suggest verifying it at the tank like AuroraGirl recommended. It's entirely possible that someone put a 2 line pump in and just didn't connect the return. I would also be careful about just swapping the pump without verifying that is the problem. For some reason new pumps are specc'd for 9psi and almost all of the old carburetors hate them without some additional work. The quadrajets seem to do ok if you lower the float level a little bit more than specified to compensate for the extra pressure, but there have been quite a few threads on here with people having flooding issues on their edelbrocks due to too much fuel pressure. I would recommend some troubleshooting to identify the actual problem before throwing parts at it and potentially causing more issues. These old trucks seem to break something extra I wasn't intending on changing every time I touch something else.
 

gotyourgoat

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Yep! That's not to say that it is supposed to though. I would suggest verifying it at the tank like AuroraGirl recommended. It's entirely possible that someone put a 2 line pump in and just didn't connect the return. I would also be careful about just swapping the pump without verifying that is the problem. For some reason new pumps are specc'd for 9psi and almost all of the old carburetors hate them without some additional work. The quadrajets seem to do ok if you lower the float level a little bit more than specified to compensate for the extra pressure, but there have been quite a few threads on here with people having flooding issues on their edelbrocks due to too much fuel pressure. I would recommend some troubleshooting to identify the actual problem before throwing parts at it and potentially causing more issues. These old trucks seem to break something extra I wasn't intending on changing every time I touch something else.
Yeah what he said. From the pics the fuel system has had more done to it than just a pump replacement. Maybe the non return pump was just whatever was on hand at the time.

@AuroraGirl I don't like that fuel pump.
 
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AuroraGirl

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Yeah what he said. From the pics the fuel system has had more done to it than just a pump replacement. Maybe the non return pump was just whatever was on hand at the time.

@AuroraGirl I don't like that fuel pump.

My neither.

Curious, what do you dislike?
 

gotyourgoat

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My neither.

Curious, what do you dislike?
You kidding? That thing is a trouble maker, a rabblerouser, and an all around problem for those who go near it.

Do you even read your own threads?
 

AuroraGirl

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You kidding? That thing is a trouble maker, a rabblerouser, and an all around problem for those who go near it.

Do you even read your own threads?
But the only thing I see wrong with it is the oily coating which is from an old oil leak. In asking if it's installed incorrectly or the lines are not routed properly. I'm trying to learn not argue.
 

SquareRoot

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Shitcan it and do an LS swap. New tanks (87 newer). Appropriate pumps.
 

Ewhitaker0020

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Okay, I've got some new info on the situation. He told me that when he stopped the truck to look at it, the ground for the choke had worked itself off the post. So he reconnected it and finished driving and he said it still ran poorly.

I just went and started it and the truck was very hard to start. Had to crank it forever and keep giving it gas to keep it running. Finally it would idle on its own, but very poorly, lots of missing. After about 5 minutes the idle smoothed a little and I adjusted the idle mixture screws out to 3-1/2 turns out and it smoothed out even more.

Finally the truck was idling smoothly and I could screw the mixture screws in to about 3 turns and keep the truck running. I walked inside and left it running for a while. When I came back out the truck was barely running. Missing really badly.

What could cause it to run like crap then run great for 5 minutes and then run like crap again without me messing with it. If the timing was off then wouldn't it just run like crap all the time. And all of this was after the truck warmed up and the choke was fully open.

The only theory I can come up with is the choke wire came off, caused the choke to close, the truck ran super rich and fouled the plugs. I was hoping after hooking up the choke it would clear itself up, but that doesn't seem to be the case.

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