[cor66vette]

As the title suggests, my 75 auto hesitates when accelerating from a stop. Drives fine otherwise, and everything is hunkie-dorie - it just hesitates at that point.

From what I can see, and without taking anything apart, all looks good. I'm not used to this car yet, so I'm hoping you experienced C3 guys will chime in.

Thanks:thumbsup:

 

[Lethal Tendencies]

I know my '75 did the same thing when I bought it. I switched to a Holley 4175 quadrjet replacement carb. Now the car runs perfect.

 

[[email protected]]

accelerator pump out of adjustment , not pumping instantly or not pumping ... slow timing

 

[C3blackvette]

accelerator pump out of adjustment , not pumping instantly or not pumping ... slow timing

You could take the air cleaner off and look down the primary side as you open the throttle. A good stream of gas should squirt down into the carb from the 2 jets.

 

[cor66vette]

I know my '75 did the same thing when I bought it. I switched to a Holley 4175 quadrjet replacement carb. Now the car runs perfect.

I'm hoping to remedy this without changing out the carburetor.

accelerator pump out of adjustment , not pumping instantly or not pumping ... slow timing

You could take the air cleaner off and look down the primary side as you open the throttle. A good stream of gas should squirt down into the carb from the 2 jets.

@fish and C3 - thanks for that. The stream looks nice and steady.

I didn't check the in-carb filter. Worth a try? Thanks, guys. :cheers:

 

[Shattered]

sting, I had a '77 Blazer with a problem like you're having. I did away with the in carb filter, and installed an inline filter instead. No more problem. Just a suggestion.

 

[cor66vette]

sting, I had a '77 Blazer with a problem like you're having. I did away with the in carb filter, and installed an inline filter instead. No more problem. Just a suggestion.

I think my next to-do is to check the in-carb filter.

 

[C3blackvette]

I think my next to-do is to check the in-carb filter.

As you replace the filter, since your there already, check the vacuum hose connections.

 

[toobroketoretire]

accelerator pump out of adjustment , not pumping instantly or not pumping ... slow timing

Over time the accelerator pump piston gets worn and doesn't shoot a STRONG stream. A hesitation off idle is almost always caused by a weak or inoperative accelerator pump.

 

[[email protected]]

I think my next to-do is to check the in-carb filter.

if you are sure your accelerator pump is strong and also pumping instantaneously with the slightest move of the throttle, then check your vacuum advance with a timing light to see if its functioning properly.. it helps responsiveness at low rpm