1993 Honda Accord LX, Vibration

Just picked up a 93 Accord LX 133k mi, w/Auto/AC. Runs great, just has what I consider to be an excessive anount of vibration when idling in or out of gear and that you can feel while driving. When I got it home I popped the hood and put it in gear(forward and reverse) with a little gas and noticed a bit of rise in drive from the front of the car. I picked up a new forward motor mount thinking this might be it. But after reading about all the out of sync balance shaft issues with these motors, I'm leaning toward that now and wan't to verify. I have'nt picked up a manual for it yet.

Is there an easy way to verify that they are still in sync ?

Thanks,

Update: I picked up a timing/balance belt and pulley w/waterpump/gasket kit. Finished installing it today. Found that the timing was off by 1 tooth(advanced , ran fine) and the balance shafts were both out of sync. It idles great now with no vibration whatsoever in the steering wheel which is where I was really feeling it all the time. I gotta wonder if this is what took out the (3)motor mounts...

If you had balance shaft issues you would have harmonic vibrations occuring in higher rpm ranges as well when driving...I doubt that's the problem.

When I worked in the shop I found a lot of Hondas to be really vibey at idle, especially with the A/C on in gear. The older ones you can adjust the idle mixture screw (recessed brass or aluminum flat screw near the throttle plate)...at some point they began capping them so they couldn't be adjusted, but I don't remember what year that happened. I think on a '93 you can still do it.

Fattening up the idle mix slightly makes for a more stable idle that doesn't have that vibey harshness to it...FI engines tend to drift towards running too lean as they age and more idle air bypasses the worn throttle plate, etc...

It could still be a bad mount or restrictor, which is common on them also, but see if you can adjust it out first...

Turn the screw slowly counter-clockwise slowly with the motor fully warmed up and idling. Remember exactly how many turns you turn it so it can be set back if it has no effect. You will probably feel the idle come up just a bit (maybe 50 rpm) and the engine smooth out. Typically this takes no more than 2 turns, probably less. Don't go more than four at any rate. You don't want to loose that screw. When it seems that turning it more doesn't have any further effect, stop, and go about 1/4-1/2 turn back in. Now put it in gear and see what you think...

http://images5.theimagehosting.com/wscrew.th.jpg (http://server5.theimagehosting.com/image.php?img=wscrew.jpg)

Here's a Honda throttle body...click to enlarge and I circled the mixture screw (it's kinda hard to see my circle, sorry)...yours may not be exactly the same but should be very similar.

I re-read your post and you seem to be saying you feel it when moving at speed too?

Please tell me more...I may have gone off on the wrong track here...or you may have a couple of different issues....

If you have vibration when moving, does it get bad in the same RPM range in each gear?

No easy way to verify the shaft clocking other than remove the timing cover and eyeball it...

Vibration stays the same through out acceleration as well.

I'm going to go ahead and replace the forward motor mount as I think it has way too much movement.

After that I'll check the vibration and adjust the idle mixture as needed.

I rechecked the forward motor mount and it's definetly broke on the top end. I'll be replacing it this weekend.

I did however take the time to check the idle and made a minor adjustment of 1 turn out, about 75rpms. This smoothed it out a bit more, especially when the A/c was on. It looks like the entire throttle body and intake has been replaced.

Thanks,

Thanks All !