Engine breaking up in first gear?

[396chevelle]

My engine sounds like it's on the high speed rev limiter when I shift from 1st to 2nd. I am running a n/a bbc in a 72 chevelle. I am running a auto meter tach and shift light. For ignition I have a msd 6-al with a 3 step limiter. High speed is 7800 trands brake is 4500 and 6500 for the burn out. I have the shift light at 7200.

At first I thought I was shifting too late. Then I noticed that the breaking up starts as the shift light comes on. The engine sounds fine 2nd to 3rd and when going through the traps with the light on.

I raised the float levels and put a rubber hose between the air vents, no change.

Any thoughts?

Thanks Cary

[Chris Uratchko]

Before you do anything, pull ALL the chips out.


Obviously it could be fuel and ignition(other) related but I'd pull the chips first.

[396chevelle]

I pulled all the chips except the shift light. The breaking up went away. I returned them one at a time untill I found that everything was working until I put the high speed chip in, then the breaking up returned. I just lowered the shift rpm in the light and my problems went away. Either I just take too long to shift or my shift light chip wasn't working right.
Thanks
Cary

[Chris Uratchko]

The number on those chips is not gospel.... I've seen them off more than 500 rpm before.

Just put antoher one of the same value in, or increase the limit.

[396chevelle]

Ok I will try that.
Thanks again
Cary

[KST]

Buy a MSD buss box (tester) and check all your chips. I have not found one chip that is not off some.

[396chevelle]

Buy a MSD buss box (tester) and check all your chips. I have not found one chip that is not off some.

Great! Thats a real confidence builder.