edelbrock carb help-breaking up 3500-6k rpm

[blckstng96]

im not much of a carb guy at all but im having this odd problem with my car.for some reason it breaks up between 3500 and 6k rpm,under load or just in neutral .if you try and hold it at say 4 the break up is pretty bad.this sucks because i can't launch the car on slicks because it breaks up right where i need to be launching.fuel pressure is good and my ignition is good,its an msd brand new.any ideas.its an edelbrock 600 bolted to a victor jr on and otherwise stock motor.

 

[Fast63]

What do you mean by "fuel pressure is good"? With an edelbrock, you can't run over 6 psi, and I would run 5-5.5 to be safe.

And what exactly do you mean by breaking up? Is it losing power? Is it missing? I would take a couple spark plugs out to see what they look like, that will give an indication as to what is going on. Let us know what you see with those.

Also, just because the distributor is MSD and it's brand new, doesn't mean you can rule it out. 9 times out of ten "breaking up" is ignition related in my experience.

 

[Rick James]

I agree ,its ignition related.Could be the box or distributor,coil,wires or even plugs.When did it start acting up?Whats the base timing at?How about total timing when the distributor advances?mechanical or vacuam advance?

 

[mrmustangman357]

+1 check total timing at 3600 rpm