I have a 75 with a 350/355 rebuilt with a fuel problem that I know a little of the history. The initial problem was that from a dead start to about 85/90mphr I encountered something that would not allow the car to continue accellerating smoothly. And after some carb adjustments the mechanic said that the mechanical fuel pump could not keep the bowls full. I installed a new fuel pump (Holley 110gph) and now at 85/90mph I have the strong smell of fuel, and the car loses some accelleration. I now believe the carb needs to be readjusted somewhat back to what it was, however I do not want to pay another $100 to have this done. I do have some mechanical abilities and I am willing to try any reasonable suggestions! The carb is a Holley 650 DP #4777. I really appreciate your suggestions! Thanks!!
Gerry

gmacp said:And after some carb adjustments the mechanic said that the mechanical fuel pump could not keep the bowls full. I installed a new fuel pump (Holley 110gph)

have you checked the floats levels..

he may have loosened them up to get more fuel in..

but now that you have proper pressure they are over filling the bowls..

id check float levels first..

|UPDATED|6/19/2004 10:48:21 PM (AZT)|/UPDATED|

Thats basically what I am asking is how to adjust the floats. Sorry I did not explain myself very well. I know very little of carbs. I bought the car from my best friend who was going to help me with all of the finer details. Unfortunately he passed away in Sept from an anuerism. I want to do as much myself as to learn, also to save some of my hard earned $$! Thanks!! I have tried some google searches but have not come up with any selfhelp!
Gerry

Also check the fuel pressure, and make sure it is not too much as to force fuel past the needle and seat. If you are not running a fuel pressure regulator, you may need one for the new pump.

|UPDATED|6/20/2004 5:39:50 AM (AZT)|/UPDATED|

KevinZ said: Also check the fuel pressure, and make sure it is not too much as to force fuel past the needle and seat. If you are not running a fuel pressure regulator, you may need one for the new pump.

I was thinking the exact same thing. Seems like this happens a lot when people install a high performance fuel pump. I know the Holley carb will take more fuel pressure then the Rochester, but I'm not sure as to how much. I'm sure someone here knows. If memory serves the Holley has some plugs on the side of each bowl where the fuel level should be, there may be an adjustment screw behind those plugs to adjust it. Adjustment will not be possible if the fuel pressure is too high and flooding the carb. Here is a link that I'm certain will help a whole bunch: http://www.holley.com/HiOctn/TechServ/TechInfo/FMCTech.html

|UPDATED|6/20/2004 6:17:21 AM (AZT)|/UPDATED|

float level. Position the car on a flat level surface and start the engine. Remove the sight plugs and check to see that the fuel level reaches the bottom threads of the sight plug port.A plus or minus tolerance of 1/32 in. is acceptable.To change the level, loosen the fuel inlet needle Locking screw and adjust the nut.They are found on the front and back bowls Its a screw and a nut just above the fuel line going into the carb. clockwise lowers the fuel level counterclockwise raises it.Turn the nut 1/16 turn for 1/16 inch desired change.The chevy corvette repair manual or the chilton corvette repair manual has all this info. Good luck. If im not mistaken 7 pounds is pressure recomended on the holley.

|UPDATED|6/20/2004 7:36:33 AM (AZT)|/UPDATED|

KevinZ said: Also check the fuel pressure, and make sure it is not too much as to force fuel past the needle and seat. If you are not running a fuel pressure regulator, you may need one for the new pump.

you should have installed a fuel regulator with that holley pump... the 110 pump is the holley blue (my fav) and comes with a regulator..

you certainly should have this installed and should not adjust carb without it. assuming you do... follow the directions above to adjust float level

put some rags under the sight plug holes to keep gas from running onto intake manifold in case floats are set to high at startup before adjusting, keep a rag in your pocket to mop up any gas that leaks past the adjusting nut and screw during adjustment.

If its 110 gph mech fuel pump no regulator is required.

Common mistake most people make is not resetting the fuel level after a fuel pump change.

I think someone above told how to set the correct fuel level. Remember he nut moves the fuel level up and down in the bowl, not the screw. you won't need to turn the nut, but just a small amount. If you turn it too much you can screw the needle too far into the fuel bowl. Easy way to know if you have done this is if you turn the nut over and over and there is no fuel level change.

To correct all you need to do is remove the screw and nut and you will see the brass needle that the nut is suppose to engage. Take a pair of needle nose pliars and screw it out. Once it is out, slip the nut back on, add the screw and your good to go. If you do take these apart don't forget to put the gaskets back in place. There will be one between the nut and bowl and between the nut and screw head.