Author Topic: Vacuum diagram needed  (Read 524 times)

Offline Moonshadows

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Vacuum diagram needed
« on: June 26, 2018, 09:21:48 AM »
Im in need of a vacuum diagram for a 1983 c10 4.1L (250cid) L6 engine California Smog manual trans NO air pump. My underhood diagram has been obliterated and the only part I can read is the code (top left corner, usually two large letters) stArted with a D
This engine has the two barrel variable Venturi carb (not sure if that is the correct term) and I want to hook it all up correctly before driving 1400 miles home through the desert!!!

Offline Irish_Alley

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Re: Vacuum diagram needed
« Reply #1 on: June 26, 2018, 10:48:12 AM »

take a look there. you will find manuals for your truck
If you cant tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Henry

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Re: Vacuum diagram needed
« Reply #2 on: June 26, 2018, 11:33:36 AM »
Hi Moonshadows:
If you cant find a diagram in the manuals, you may take a look at the Autozone website collection of vacuum hose diagrams for the Chevy truck:

Although they do not have diagrams for 1981-1983, they do have them for up to 1980 and 1984 onwards. There is a diagram for 1980 that is coded "DT" and shows a 2-barrel carb. If all your emissions stuff is still there, you should be able to compare what you have with the diagrams and figure out what hose goes where.

If your carb is original to your truck, it is probably a Rochester 2SE or E2SE. These carbs were known as the "Varajets" and maybe this is your confusion as to "variable venturi". Yours is most likely the E2SE which has computer controlled metering. There has not been a variable venturi carburetor made in the USA for a street car in a long time, if ever...My last recollection of a variable venturi carb made in USA was for WWII aircraft engine. Variable venturi carbs are common on motorcycle engines, all out racing engines and some older British cars.