LT4 LT4 1000RPM vibration

[jaespojr]

I get a fairly strong vibration at exactly (visually looking at dash tach) 1000RPM.
It is hard to get the accelerator pressure exactly right to hold it there as it wants to rev quickly. I pass through this RPM so quickly when shifting and don't feel a vibe at higher RPMS

Does anyone else get this? I had the harmonic balancer off to change the optispark, but it is indexed the way it came off, (there's a yellow line on the hub bump and a yellow triangle on the balancer, which are lined up.)

Any thoughts?
-John

 

[LT4man]

I would make sure all your plug wires are pushed all the way on to the cap. They fit very snug and you should hear them click into place.

Did you use any dielectric grease in the plug wire boots?

I realize you have reassembled everything. It is possible (although difficult) to at least make sure they are all tight.

SAVE THE

 

[jaespojr]

Thanks, I'll check em again

I'll check them again, they're new MSD wires and made a nice double click on the optispark side (I still checked them all about 10 times before I put it back together) I also did go over the plug wires and repushed them all, twice now. I used a q-tip and ran thin coat of dielectric grease around each boot inner side without gooping up the conductor.

This doesn't throw a code (wouldn't it?) or sound like a miss, it's a strong mechanical resonance at 1000 RPM.


Thanks again for reponding
-John

 

[4CAM LT5]

Never felt this kind of vibration on mine. Solid as a rock.

Hope you can track-down this gremlin.

 

[LT4man]

How many miles on the Vette?

Did you do any exhaust work recently?

Did you disconnect the engine mounts recently?

Just some more ideas!

SAVE THE

 

[6 Shooter]

I think Dale Jr. said the last 6 DEI/RCR engines all vibrated @ 1000 RPM's right before they Blew-Up!

​

Later . . . . . .
6 Shooter

 

[Louis Bartay]

I think Dale Jr. said the last 6 DEI/RCR engines all vibrated @ 1000 RPM's right before they Blew-Up!

​

Later . . . . . .
6 Shooter

If my LT4 was having a problem, a joke about it would be uncool. Unless you are his friend.

Check the balancer and make sure it is installed correctly. But I bet you have. Just a thought. Was it doing this before you replaced the parts??

 

[6 Shooter]

If my LT4 was having a problem, a joke about it would be uncool. Unless you are his friend.

WOW - I thought we were all friends! ​

L8TR - D