I did the search and read all the previous posting...
Please any ideas,
On my stock 91 teg. I am having a hell of a time trying to stop the rough shaking at idle @750 rpm's.
I recently change, wires, cap and rotor, pcv, oil change, timing belt, lower front motor mount, fuel filter. I changed plugs a year ago, but only drove 6k miles on the new plugs. At idle 750rpm shaking is unbearable, but if i shift to neutral or park, it's good. Why does that increase of maybe 50-100rpm'smake sure a difference? I have 110,000 miles. Please educate me, any idea's..

 

I'm thinking loose belts. Does it have misfires, or back fires? They might be barely noticeable...


[Modified by B21A, 7:56 PM 10/8/2001]

 

I haven't noticed any mis firing... I do here a squeaking pulley..

 

sounds like there is just something loose. As far as it only shaking at certain rpms that probably has something to do with natural frequency of certain objects in the car. So i wouldn't worry about that was much as finding the thing thats probably loose

 

When I mean shaking, i mean the engine, steering wheel, dash, etc..
You can feel it and hear it.
Thanks,

 

Definately has the symptoms of bad, worn, stiff or bent motor mount(s)..
Does the car shake more noticeably in "drive" or "reverse"??
In most cases it will shake more in while in drive then reverse, and there is a way to minmize the shake in drive, but you first have to determine if the problem is a shake in the motor or an erratic idle..

 

I think the shake is in the motor, because the idle is pretty solid @750rpm's...
and I can see the motor shaking. I changed the lower front end mount about 5
months ago. Do you think it can be the top mounts ? how can i check?

 

One method I have of adjusting motor mounts is..

Locate and loosen the Mount Bolts ( the long bolt that goes through the dampener) on the following mounts

Front Motor mount
Left Side Motor mount
Right Side Transmission mount

If you can access the lower rear mount, then loosen this as well, I've had success without touching this mount and isn't necessary..
Start the car and cycle through all the gears, (from Park down to D1 or 1st-Reverse) and back again.. put the car in Nuetral, apply the Emergency brake and go tighten all the mount bolts you have loosened.. and thats it! this method clears up a majority of engine shake problems..

Another cause of excessive motor shake is a bent lower hanger beam underneath the motor, this is the beam that runs from the rear sub-frame beam to the front sub-frame beam, this is the beam thats runs right underneath where the engine block meets the transmission housing.. you can adjust this the same way as the motor mount adjustment if needed..

Early 90 series Accords also had a vacuum controlled rear motor mount that will also create a vibration if the mount is bad or not getting proper vacuum to work properly.. check to see if the vacuum lines are hooked up and the motor mount adjuster moves freely..

 

Valve clearance tht is too tight will cause a rough idle as well- it is probably a combination of mounts and engine vibration- are your spark plugs too hot? use NGK plugs- not champion lawnmower ****. IS your belt timing right on? did you do the work yourself? Use a Honda PCV valve- aftermarket pcv valve tend to cause a slightly rougher idle as well. They are one size fits nothing.


[Modified by fixhondas, 3:28 AM 10/10/2001]


[Modified by fixhondas, 3:35 AM 10/10/2001]

 

has your car been wrecked in the front

 

And this includes little "fender benders" as well, it doesn't take much to shift those motor mounts around..

 

Yes, I did have a little fender bender in the front. Someone backed into my car..