[michaelem]

I have a 1968 el camino with a 290 HP 350 Chevrolet engine. I recently had my carb rebuilt. It had a blown power valve and needed new needle and seats. It a (4777-S) Holley 650 double pumper with mechanical secondaries. It about a year and a half old and I bought it new. Ever since the rebuild it's running really bad, espically when the engine is cold. This is kinda hard to explain what it is doing but when stepping on the gas lightly to get moving it is ok until I step on it more. When the Vac reached 5 to 8 inches it just completely bogges down and then the power comes right back and it starts running good again. It does this really bad when the engine is cold. I'm suspecting the new power valve in the carb is the wrong vacuum size? Before the carb was rebuilt it did not do this and now the carb has all new parts it just doesn't run like it did before the rebuild. Anyone know if this sounds like the power valve in the carb? Maybe like it's the wrong vacuum power valve. I really would appreciate any feedback anyone might have for me. Thanks!

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Michael Minery
Orange, California
1968 Malibu El Camino
<A HREF="http://www.angelfire.com/ca/mineryhomepage/1968elcamino.html" TARGET=_blank>My 1968 El
Camino page</A>

 

[COPO]

Check my link here http://members.rogers.com/mlvd/holley.htm

I know you have a DP, but most of the settings will be the same as a sec vacuum carb. If it's falling on it's face when cold and you don't have a choke connected then wait till the engine is warm before stomping it. If you have a choke then it needs to be set up. I keep my choke screwed open all year just so it doesn't accidently flop shut by accident like it did once. If it bogs after being warmed up then the incorrect squiter size or accelerator cam is incorrect for the engine.

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Mark
Home Page
http://members.rogers.com/mlvd/
http://members.rogers.com/1970-z28/

[This message has been edited by COPO (edited 12-11-2001).]

 

[Randy Mosier]

There is an adjustment on the accelerator pump arm and if the person who rebuilt it tinkered with it any, it may not be squirting enough fuel when give it the gas.