Cliff's Quadrajet Parts and Rebuild Kits

Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: liberty on November 23, 2009, 09:32:25 PM

Title: Hesitation on initial acceleration
Post by: liberty on November 23, 2009, 09:32:25 PM
Carburetor: Edelbrock Quadrajet (NOS)   Numbers: 1904, 8907, 0870 W

Problem:  Hesitation, from a stop, during initial acceleration. No other hesitation or problems.  This carb had never been used since manufactured.

A different Quadrajet (Rochester) had been on this engine/car with no hesitation – all sources of vacuum leaks have been checked.

Are there any exterior correcting adjustments?  If not – recommendation/solution?   
Title: Re: Hesitation on initial acceleration
Post by: Schurkey on November 24, 2009, 08:17:26 AM
Carburetor: Edelbrock Quadrajet (NOS)   Numbers: 1904, 8907, 0870 W

Problem:  Hesitation, from a stop, during initial acceleration. No other hesitation or problems.  This carb had never been used since manufactured.

A different Quadrajet (Rochester) had been on this engine/car with no hesitation – all sources of vacuum leaks have been checked.

Are there any exterior correcting adjustments?  If not – recommendation/solution?   

Does the accelerator pump work?

Is the air valve spring-loaded shut?
Title: Re: Hesitation on initial acceleration
Post by: liberty on November 29, 2009, 09:16:55 AM


I've decided to start diagnostic by richening APT.
Title: Re: Hesitation on initial acceleration
Post by: omaha on November 30, 2009, 12:46:16 AM
that would be worth a try. If it is an edelbrock, it still must be fairly old as they were disco'd some years ago. I would get a new accel pump and top gasket.  My guess is the accel pump is not sealing (from sitting too long).....just my first guess.  [cliff's got the good one's!!]  one trick: disconect the accel pump linkage and try driving it, see if it makes a difference. If no difference,[or little difference] accel pump is probably bad. {try this after the car has warmed, it'll be easier to start}