Engine trouble
Thread Starter
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Joined: Sep 2009
Posts: 97
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From: iowa
Engine trouble
well, my 1977 vette boggs out everytime i step on it. i just did a fresh tune up but it still does it. i think it may be the carb but im not sure. does anyone know what is going on with my vette?
Safety Car
Joined: Oct 2006
Posts: 3,993
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From: Gig Harbor WA
Melting Slicks
Joined: Mar 2007
Posts: 2,520
Likes: 11
From: Hinckley OH
It could be the accelerator pump in the carb. With the engine off look down the bore of the carb and move the linkage quickly. You should see two steady streams of gas shoot into the bore. If they are not good streams, replace the accellerator pump.
Racer
Joined: Aug 2004
Posts: 419
Likes: 4
From: Lewisville TX
Also, check your fuel filter. Could be it needs to be replaced.
You can try running without it and see if your problem is solved.
Another prob.. fuel pump is going south.. not getting enough gas to keep up.
You can try running without it and see if your problem is solved.
Another prob.. fuel pump is going south.. not getting enough gas to keep up.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
An immediate bog is usually due to a bad/worn seal on the accel pump piston. It could also be due to a clogged passage in that same system, but that is more unlikely if you have had a good filter installed. You can test this by lifting hood and removing the air cleaner. With engine OFF, look down into the primary [front] venturi, then exercise the throttle linkage to WOT quickly. You should see a strong squirt of fuel into the venturi [both sides]. If you do not, or if it is not the same on both sides, there is a problem with the accelerator pump circuit.
It's possible to change the piston seal with the carb on the car, but I would not recommend it if you are not well experienced at working on Q-Jets. If it has been many years since it has been rebuilt [if ever], do a full rebuild of the carb...making sure that all the passages built into it are blown out [pressurized air] and clear. Rebuilding a Q-Jet is not a complicated process; especially, if it is original to that car. At least, you know that it is configured properly to begin with.
It's possible to change the piston seal with the carb on the car, but I would not recommend it if you are not well experienced at working on Q-Jets. If it has been many years since it has been rebuilt [if ever], do a full rebuild of the carb...making sure that all the passages built into it are blown out [pressurized air] and clear. Rebuilding a Q-Jet is not a complicated process; especially, if it is original to that car. At least, you know that it is configured properly to begin with.
