Need help diagnosing problem.
#1
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Need help diagnosing problem.
After starting a thread yesterday about a few odd problems I was having I got off track and began to ask other questions. I thought I should make a thread specifically for this problem alone.
While driving or off idle (doesnt matter) if I go WOT I get a very bad hesitation. Picture yourself driving your Nova and punching the throttle. The first thing you would expect is to get thrown into your chair right? Well the first thing that happens to me is the motor seemingly goes quiet and I get pushed forward like I have lost all power. Then the power comes on strong and shreds the tires. When going to the next gear there is a slight pause but never nearly as pronounced as when first going WOT.
What could cause this? What I have heard so far is that maybe the springs in my MSD distributor are weak. I have also heard that the Carb secondaries are either opening to soon or to late.
One guy told me to mess with the spring tension on the secondary spring to see if it gets better or worse (depending on if I loosen or tighten the pressure.
Ideas ?
Thanks for the help. I will be cross posting this to LS1techs carb section for more help.
Mike
While driving or off idle (doesnt matter) if I go WOT I get a very bad hesitation. Picture yourself driving your Nova and punching the throttle. The first thing you would expect is to get thrown into your chair right? Well the first thing that happens to me is the motor seemingly goes quiet and I get pushed forward like I have lost all power. Then the power comes on strong and shreds the tires. When going to the next gear there is a slight pause but never nearly as pronounced as when first going WOT.
What could cause this? What I have heard so far is that maybe the springs in my MSD distributor are weak. I have also heard that the Carb secondaries are either opening to soon or to late.
One guy told me to mess with the spring tension on the secondary spring to see if it gets better or worse (depending on if I loosen or tighten the pressure.
Ideas ?
Thanks for the help. I will be cross posting this to LS1techs carb section for more help.
Mike
#2
usually a hesitation like this is a result of the accelerator pump. what type of carb is on the car. if its a holley or demon carb you should have slight preload on the accelerator pump from the arm that moves it. you can try tightening the screw to release the pressure abit, most times a stumble like that is too much fuel. try going in half turn increments on the accelerator pump and see if that helps, if it is an edelbrock the accelerator pump is on a rod and that has 3 holes in it usually the middle hole is a good base for most engines. u could go either way again and experiment a bit. it also could be the secondaries, if you are not getting a lean pop through the carb then again it is probably too rich, try putting a stiffer spring in the secondary diaphram, sounds like they are coming on too soon. the longer "yellow" spring is usually a good starting point for the secondaries.
#6
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I moved the accelerator pump to the bottom hole and it seemed to clean alot of the hesitation up. I am going to drive it more today and report back tonight to let everyone know where I am. I am also going to check the top end of the engine for vacuum leaks as well..thanks alot