in the last two weeks or so, my car has started to run extremly rich. i have a 750 VS holley, it was running great, then it started to run so rich i cant stand by the car while its running. any ideas what i should adjust? what would make the carb start running richer?

 

check the fuel level in the bowls, they have been known to become "out-of-whack" from time to time. if they're ok then you may be having a problem with fuel pressure, if your using an electric pump with a regulator on it check that and make sure you are getting the proper amount of pressure.

 

Blown power valve, probably the primary

Change it before you touch anything else

 

checked the fuel bowls, fuel just starts to dribble out when i pull the plugs, is this good? also replaced the power valve, and still no luck can i have the wrong size power valve?

i use a mechanical fuel pump.

could anything else be blown inside the carb? could the mechanical pump have to much pressure?

Thanks

 

you may want to check the fuel pressure with a gauge but I doubt that's it, most mechanical pumps are designed for carb. pressures. did you check the fuel level with the motor running or off, check the level with the motor running if you have a messed up needle valve it should show up with the motor running.

lastly, you can try adjusting the idle mixture screws on the carb. if the carb is older sometimes the screws don't stay in place very well and will back out of adjustment.

 

with the engine running, take off the air filter, and look at the boosters. (primary and secondary) if there is fuel dripping from them, the needle and seat *** has got some grit in it, causing flooding.

if so, remove the needle and seat (count how many turns it takes) and clean it out.

if there is dirt on it, fit a paper fuel filter rather than the mesh type.

 

how can u tell if its running lean or rich?

 

black smoke / slow loppy idle = rich,

spitting / stumbling / popping = lean

in basic terms....

 

Holley air bleeds are also notorious for getting plugged with fuel varnish and general " gunk ". Get a good carb cleaner ( CRC's very good ) and spray the air bleeds, with the engine running, on both the Primary and Secondary sides. I make this a regular mainatnence item every couple of months. May cure the problem.

Also check the " tightness " of the Fuel bowl screws. They can loosen after awhile and then you can get fuel leakge through the circuitry. Have to be fairly tight...not just snug.

 

thanks> i get smoke on start up when it cold outside but it stops after about 5 min of driveing is that narmal?

 

What color smoke? Black , blueish or white? You should probably start another thread on this so as to not " Hijack" the original thread.

Include the full specs on your engine.