Engine hesitation...makin me angry!

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Ok. first things first. Ill explain what my car is doing than ill explain what ive done to fix this. OK when im driving ill come to a stop sign and ill stop but when i press the pedal the car will kind of lerch forward an inch than sound like its gonna kill until i let off. This meens i have to tap the pedal to get going untill im movin a bit faster. Ive had people look at my carbourator and everything and ive changed the vacume advance and everything. The car was running fine yesterday and earlier today but when i was on my way home it was acting up again. Its killed several times at stop signs and i can floor it and it takes time to even get to 55. the motor is a 1973 chevy small block 307 with a 2 berral carb stock. please help ive also changed the stone filter and my in line filter. I hope thats enough info for a solution.

posted by  sandlercd_22

Decelleration hesitation is usually caused from getting a gutful of air and insufficient fuel. You need to check for leaking vacuum hoses, gaskets etc.

Check the idle mixture adjustment. Did the carb guys check the emulsion tube?

Check your PCV valve is shutting at idle.

Check your brake booster vacuum line for cracks.

posted by  Wally

He checked my vacume hoses wich is why he determined it was the vacume advance, wich i replaced. It was working real good today with little or no hesitation. i just figured that the rubber diaphram in the vacume advance needed to stretch out like a balloon to work properly, i guess i was wrong. Ill relay this info to my stepdad to see what he makes of it. Im not good with carbourators.

posted by  sandlercd_22

Try to spray a little carb and choke cleaner around the carb and intake manafold will it is idoling, if it stalls or sputters there is a leak in the intake gasket, if you spray it higher in between the carb and intake and it stalls or sputters it is a bad carb gasket. If the brake booster was going bad you would notice a very hard pedal when you try to stop. You would really have to stomp on the brakes. There is an air leak some where or the carb is not adjusted properly. Make sure air filter, pcv, are new. BE CAREFULL NOT TO SPRAY TO MUCH CARB AND CHOKE CLEANER NEAR HOT EXHUAST MANAFOLDS IT IS FLAMABLE

posted by  bigjim_h

The breaks have always been kinda hard, not difficult to stop, just took some getting used to like having to press the pedal a little bit further from the stop sign than say my moms LHS. I did notice some bubbling around the base of the carb through what to me (yes i am stupid with carbs so please insert insult here) look like the carb gasket. But the thing is we redid all that when my car was stalling from crap that was in the gas tank when we cleaned out the carb. I just dont know why it would work one hour than not the next.

posted by  sandlercd_22

tuning your carb will probably fix your problem

posted by  carlos

i agree, also, just curious but what kinda car ya driving?? maybe a malibu or nova??

posted by  adamc44

Nova. Its funny though when i took it to work today it ran just fine. No hesitation at all. Not that thats a bad thing its just i think its eather the long lost brother of herbie or Christine...

posted by  sandlercd_22

I don't know why deceleration hesitation was mentioned...he said that after he got on it from a dead stand still it would basically bog and he had to feather the throttle...that pig is running fat on fuel(rich). Carb adjustments maybe necessary and possibly even a rebuild...go to a well-known, qualified carb tuner...some may be able to turn some screws but don't really know what they're doing. It's a possibility that you're floats could be hanging up also.

If you continue having the problem, drive around at low speeds(below 50mph) for about a half hour then let the car cool down for a while and pull a spark plug, that'll help in figuring the problem. Doesn't sound like a lean problem at all to me.

posted by  Sick88Tbird

Well i think that the car had been sitting in a feild for awile somewhere because we had taken apart the carb in like april and cleaned it and replaced the stone filter and added a inline filter and after that it never flooded. We did all that because the floats were stuck with crap from the gas tank. but just recently i took the carb apart myself and cleaned it out and put it together and thats when i started getting my problems. For about a week it would eather kill or damn near kill at a stand still even when i was easing out of a stop sign. But now it seems to be working fine. My stepdad says it may just be bad gas in the tank.

posted by  sandlercd_22

Ok. Tonight when i was driving the car it was acting up again and right before i stop sign i got frustrated and put it in N and floored it a few times and when i got to the stop sign right before i went i shifted it into drive and it jumped really hard from the revving. ever sense i did that it ran PERFECT. to the point where i accually drove the speed limit in fear of messing it up again. I have no idea what i did but its working.

posted by  sandlercd_22

Remove the air cleaner, and look down into the carb and operate the throttle. You should see two little squirts (jets) of fuel appear. If not then your accelerator pump is bad. It's the little round leather plunger. Use a can of wd40 with a plastic tube extension to check out all of the orifices from the pump.

Also this pump will not work if your float level is set to low (not enough fuel in bowl).

posted by  jcutsh

Ahhh yes, the good old Italian tune-up! Zoom-Zoom!!!

posted by  PTT1

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