1977 el camino emission vacuum with quadrajet

1977 el camino emission vacuum with quadrajet how to#
1977 el camino emission vacuum with quadrajet manual#

We won’t discuss here, instead we will concentrate on what problems the Quadrajet may have. Lack of power is often caused by electrical, or engine wear.

See above for the ‘rough idle’ article.

Take the idle mixture screws out and see if they are plugged.

You need to follow each one with compressed air to be sure they are open.

1977 el camino emission vacuum with quadrajet manual#

Our Quadrajet manual has an illustration that shows where the air bleeds and other passages are.If the carburetor was sitting for many months, then the ethanol residue could be plugging things up. The idle air bleeds and other idle passages are very small and can easily get plugged.If the RPM changes then you found your problem. Spray carb cleaner around the outside of the gasket. Be sure the throttle body gasket isn’t leaking.If the RPM is too high, the idle circuit will be bypassed. First of all be sure you are adjusting the idle mixture at the idle RPM.This is usually indicative of a problem with either too much air, or not enough fuel (in the idle circuit).

It was used on vehicles with air conditioning.Īdjusting Idle Mixture Doesn’t Change Anything NOTE: Even though your carburetor may have a place for the compensator to sit, it doesn’t mean it came that way. You won’t have any problem unless you get into a high heat situation, or use your air conditioner. Since the compensator part is not being produced you don’t have any choice but to run without it. In a perfect world the Idle Compensator should be installed on those applications that need it. Its purpose is to offset the enriching effects caused byexcessive fuel vapors during hot engine operation. The Hot Idle Compensator, when used on 4MC and 4MV Quadrajet carburetors (View C) is located in a chamber at therear of the carburetor float bowl adjacent to the secondary bores. He needs to have all four tubes, 17-91 is one of those numbers. My question is should I have the secondary accelerating well tubes and if I do is that the right part # ? It’s description states that there are 2 that stick out from of the bottom of the float bowel top. Looking through your parts section I found pt # 17-91 Rochester carb. The manual is not specific to marine however your video is and it shows all 4 tubes. doesn’t have the secondary accelerating well tubes. 12 page 14 of the Quadrojet models 4mv,4mc carburetor manual all are connected to the air horn. What I was referring to pickup tubes are call the main well air bleed tubes (2 inside tubes ) and secondary accelerating well tubes( the 2 outside tubes) fig. Sorry about lack of knowledge and poor terminology. Make sure the jets are not loose, or plugged. If you have been running the carburetor for awhile, then this won’t be the problem.

Main metering jet may be the wrong size.

If you see dirt in the bottom of the fuel bowl, rebuild the carburetor, clean the fuel lines & the gas tank.

Dirt in the system – take the top off the carburetor.

There could also be a leak at the intake manifold. If the RPM smooths out, then you found the problem.

Vacuum leak – Use spray carburetor cleaner and spray around the base of the carburetor and any vacuum lines.

Replace any fuel filters – There is usually one in the fuel inlet of the carburetor and often there will be an in-line fuel filter.

Look for any fuel restriction – check for kinks in the fuel line.Look for any cracks around the area the seat screws in.Make sure float doesn’t rubbing somewhere.Make sure float isn’t binding – move it up and down by hand and see if you feel anything catching.Bad float – For brass floats, heat up some water to prior to boiling, then immerse the float.4.5 lbs would be a go to if you can’t find the spec. Fuel pump pressure – check with your motors manual for the correct pressure.

1977 el camino emission vacuum with quadrajet how to#

Look here on how to test the needle & seat. The needle may have been damaged while adjusting the float, or dirt from the gas tank got back into the carburetor. 80% of the time this will be the problem. Here is a list of items to check when this happens (not in any order): What is flooding? Simply, there is too much gas getting into the float bowl. Gas is running out of the top, or you get a strong gas smell? This is a sign of flooding. There may be a small air restrictor in the passage that makes getting through with wire difficult. If wire doesn’t do it, try heating the outside of the passage and then blow air through. A whistle with air will indicate a clean passage. Use thin wire to clean out the passages completely. These are very small passages and get clogged easily with ethanol residue. This can be caused by several things, but there is one item often missed by the rebuilder and that is the idle tube.