Noticed the other day at 20,000 rpm car shaking violently, plugs and wires are brand new? motor was recently swapped along with a new tranny? around 18,000 rpm shakes a little, but over 20,000 its smooth? not sure whats going on or where to start, the egr valve is bad I know that for a fact, but other than that everthing is almost brand new....

84 cam 2.8l Rochester carb 2bbl

 

Maybe the turbine threw a blade?

 

Im not a expert but maybe its because you rev it 12,000RPM over the red line?!

 

Always nice when poeple are so helpful around here.....

Anyone can assume to take off 1 zero

on top of an engine swap, id check years of parts used, if you got miss matched parts from an external & internal balanced engine.....

flywheel, balance crank need to match yr.

 

don't you have yo use the flexplate and crank together because they are both balanced together. maybe the flexplate is causing the problem.

 

Not right, on certain years the flex plate had weights on it. (externally balanced) and some years had the engine internally balanced (no weights on the flex plate). I cant remember the years at the moment but i know all RWD 3.1Ls are internally balanced.

 

"the V6 went to Internal balance in 88, so 88-9 2.8s and all 3.1s and 3.4s are internally balanced"

From mavs older post on another thread. Which I remember reading a few times before.

I would think that if you did have a internally balanced engine and ran a flex plate with weights on it(externally balanced), it would definitly shake. And you would notice it. I would think the same is true if you ran a internally bal. flex plate(no weights) and a external balanced engine. I would check to make sure you have the proper parts on the engine, definitly worth looking into just to be sure.


Have you driven the car around at all when its shaking? Anything else seem weird? Transmission or tq converter....

 

After the swap all way good. Torque converter is on tight. Replaced all the suspension. It starts up rough idles ok. Running rich now. Hesitates a little and when you are on it you barley feel a thing.

I noticed the vaccum to my map sensor was off plugged that it. Ran a tad better. I'm hoping that the plugs are wires just need a swap. My theory is possibly the excessive fuel dump fouled the plugs lol

 

So instead of reconnecting the vacuum line to the MAP sensor you just plugged it? That's some place to start right there.

 

"plugged that it." easily translates to plugged that in.... not plugged off.

 

Ok what? The map sensor was changed also. The line the comes off of that was not hooked on. Sorry should of clarified

 

UPDATE!
The wires were shot, plugs were crap, and the distributor cap was shot, changed all of that shes running smoother little shake when shes cold but once shes warm no issues, im going to change the ignition coil too. I think she just needed a tune up