So would a missfire cause a slight virbration at idle or at higher rpm. How would you know if there was one since it isn't OBD2??

I have a slight vibration at idle....you can see the dash shake a bit and the stick (T5) vibrates. When you rev it it is quite smooth until you get to about 3000rpm and then there is some vibration.

Any thoughts or suggestions to help me out? I am kind of scared to rev it past 3000rpm because I am thinking it won't be good for things Am I right in assuming that it shoud be just as smooth passed 3000rpm even though this engine doesn't have a balance shaft???

By the way it is an 85 2.8.

 

any suggestions ?

 

No balance shaft. Wires/plugs/cap/rotor, just to eliminate that.

Also, timing chain stretch?

 

Sorry, shoulda mentioned, wires/cap/rotor/plugs all fairly new.

I was about to do the timing chain this past weekend but ran out of time. It's not making noise but who knows when it was last done. Hopefully this weekend. So it could contribute to this sort of thing?

So how would you know if a misfire was occurring??

 

Firt off, I'd say check your motor mounts, especially the passenger side which takes the most abuse.

I don't think you're getting any misfires, but what I do when I can't pinpoint a miss is do a power balance test. You can take short pieces of rubber hose and put them on all 6 of the distributor terminals then put the plug wire boots back over them. This will space it so you can ground each cylinder with a test light. Then, with a test light to ground, short each cylinder one by one and compare the rpm drop between all cylinders. If you short a cyl and there is a significant rpm drop then that cyl is ok. If you short one and the rpm barely changes, that's your lame cylinder. However, all this does is identify which cylinders aren't playing along, not what is causing the miss.

 

Didn't one person this year end up with a bad vib as a chunk of his crank balancer flew out? Them stock rubber balancers do dry rot easy.