Author Topic: Carburetor  (Read 862 times)

Offline Cheyenne1010

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Carburetor
« on: April 09, 2022, 07:17:22 AM »
Hey guys im Robert and i have a 1973 Chevy C10 long bed.what can i do to keep my truck from vapor locking thats not going to cost thousands of dollars.any help is very much appreciated.

Offline LILT77

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Re: Carburetor
« Reply #1 on: April 09, 2022, 11:28:35 AM »
Possibly look at a fuel vapor separator filter. Wix 33040. I know this has worked for some people. The offset nipple goes back to the tank
77 C10/Big 10 Cheyenne "Old Blue"
81 C2500 Sierra Grande "Gramps"

Offline Rapid Roy

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Re: Carburetor
« Reply #2 on: April 09, 2022, 12:19:32 PM »
If you have a metal line from pump to carb, you can get pipe insulation at Lowes or Home Depot and wrap around it. I did this from engine to pump. It is the round foam like material. So far in the last 7 years I haven't had vapor lock.

Sample of what I used. There are different ID sizes. Some has tape on both sides of split to stick together.
You can also use zip ties if the tape does not hold. I prefer to use the black ties over the white.

https://www.lowes.com/pd/Frost-King-1-2-in-Wall-Thickness-x-1-2-in-Id-x-6-ft-Foam-Pipe-Insulation/1001277248
« Last Edit: April 09, 2022, 03:16:09 PM by Rapid Roy »
1974 Cheyenne 10 LWB STOCK 350 W HEI /TH350/AC/4 BBL Quadrajet
Mopar by Birth
Chevy by Choice

Offline Cheyenne1010

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Re: Carburetor
« Reply #3 on: April 09, 2022, 04:14:11 PM »
Thank you guys for the helpful information

Offline VileZambonie

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Re: Carburetor
« Reply #4 on: April 09, 2022, 07:20:36 PM »
Are you trying to fix the symptom or the problem? These trucks do not have vapor lock issues unless someone did some butchery to cause it. Make sure the fuel tank is properly vented. If you loosen the gas cap and your vapor lock issue goes away, there's your first clue.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Big Dee

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Re: Carburetor
« Reply #5 on: April 09, 2022, 07:49:06 PM »
My engine would stop sometimes when hot. I had to change my fuel pump several times. ac delco solved the problem.
Check the return line also.
85C30...

Offline Cheyenne1010

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Re: Carburetor
« Reply #6 on: April 10, 2022, 07:37:08 AM »
It would vapor lock on me with the mechanical fuel and its done it when i installed an electric fuel pump.fuel cap is new and venting properly and I've changed the fuel filter also.when i open the gas cap while its vapor lock nothing happens.there is no the only thing i haven't change is the charcoal canister.my fuel line runs along the frame then up the front of the engine then above the intake manifold to the carburetor.my fuel pump and gas tank only has 2 lines.1 from gas tank to pump and 1 gas tank to charcoal canister,so i have no return line.

Offline JohnnyPopper

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Re: Carburetor
« Reply #7 on: April 10, 2022, 01:33:17 PM »
Had the same prob on my '73 3+3, it was my electric fuel pump was too close to the exhaust.

I could tell when VL was going to happen, the pump starts to get loud enough to hear when driving.

I used some sheet metal as a barrier.

All better... 8)

1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Cheyenne1010

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Re: Carburetor
« Reply #8 on: April 10, 2022, 03:39:40 PM »
I think thats what i need to do because my electric fuel pump is kinda close to the exhaust pipe

Offline VileZambonie

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Re: Carburetor
« Reply #9 on: April 10, 2022, 06:16:58 PM »
Unless you have an in tank fuel pump, your electric fuel pump may be the source of your issues. Make sure no fuel hoses are kinked as well. If you have a new fuel cap, is it vented or sealed? Vapor lock is when fuel boils in the fuel line. A pressure drop can cause the boiling point to drop and lead to potential vapor lock. Why do you think you have vapor lock anyway?
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Cheyenne1010

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Re: Carburetor
« Reply #10 on: April 11, 2022, 04:18:00 AM »
The reason I think it's vapor lock is because I'll be driving and my truck will turn off,it will restart for a few seconds then turn off again.i'll try again to restart and it just wont start.if i wait about 5 to 10 minutes it will start but 5 miles later it'll turn off again.this only happens when its hot outside.(90°-95°)
      I installed an electric fuel pump and i installed it exactly as the instructions said to do it and ran good for 2 years,then a few days ago it died on me,shot some starting fluid in the carburetor and it started,then 10 miles later it died again.by now its cooler outside and i had waited like 30-40 minutes without starting it.so i started it up and drove 35 miles  to my home without any problems

Offline JohnnyPopper

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Re: Carburetor
« Reply #11 on: April 11, 2022, 10:40:50 AM »
Sounds like vapor lock, does your fuel pump get louder? As in clacky? If it's trying to pump vaporized gas it gets noisy.

In any case, it sounds heat related. Curious why for 2 years it was good?

Check for exhaust leaks that would blow hot gas on any part of your fuel delivery system.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline Cheyenne1010

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Re: Carburetor
« Reply #12 on: April 11, 2022, 11:21:14 AM »
i have notice what sounds like an exhaust leak and it sounds like its coming from the collector where the exhaust manifold and exhaust pipe meet.i need to check it out real quick

Offline TexasRed

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Re: Carburetor
« Reply #13 on: April 13, 2022, 07:02:07 PM »
Can you go back to a mechanical fuel pump? You may look into adding a return line or a "vapour" or "vapor" line back to the tank. Electric pumps don't like to be dead headed. It helps both with vapour lock.

I'd make sure all your rubber lines are good and not cracked either and it's not trying to suck air instead of fuel.

Potentially could be an ignition issue too, but the starting fluid kind of points in a different direction.

Offline Cheyenne1010

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Re: Carburetor
« Reply #14 on: April 24, 2022, 11:50:51 PM »
It vapor lock on me again today and it wasnt even hot today.my sending unit only has 2 lines coming out of it,one line to the carburetor and the other to the charcoal canister.is it possible to change my sending unit to a 3 line and a mechanical fuel pump to a 3 line that way i can have a return line to the gas tank?