I´`ve got an engine vibration at 4200-4500 rpm.When the trans is in neutral, i does the
same thing so it is not the trans or the shaft.
If I put the base timing at 2 before TDC the vibration is less than if the timing is at
8 before TDC.At 2 after TDC the vibration is almost gone, but the car does not work OK in
lower rpm.With the timing at 8 or 10 before
TDC, the car runs great untill I hit 4200 rpm.
Any ideas?
Thanks
89 iroc, 350 motor.

 

Anyone?
Thanks
BenIroc

 

Back to the top, last try.

 

Just a guess, but maybe your harmonic balancer?

Good luck,

Ken

 

the balancer would be my bet or you have some strange misfire I have been told that you can have problems with the ignition module in the hei and as the rpms go up it can cause a problem such as that.

good luck

 

That`s what I thought to so I put a new balancer, the old one was finished anyway
but the vibration continued with the new balancer arrrrrgghhh.
Thanks anyway guys.