Low idle surge. The usual one

[CBAccordA4]

Anyone know tha main suspects for the low idle surge that when it drops low, it makes the vehicle vibrate. I've felt it in so many accords with f22a but thought nothing of it. Well its getting old and want to get rid of it. Its not a constant surge like the high idle surge but it surges very slowly up and down until it drops to low to a vibration and then rises back up. When I make the check engine light come on it pretty much goes away and turns to a nice smooth idle at a little under 1000 rpm. Maybe I have the idle set too low?? but whatever the ecu does when the cel is on makes it run better. Any advice is appreciated/.

[Grimsta]

It puts in in base timing mode.
Try this:
Jumper the connector for the CEL, and check your timing. The ignition timing and idle RPM specs are under the hood. Make sure your timing is correct and your base idle RPM is also correct.
Also check the dogbone in front, thats the main culprit for vibration transmission. Make sure the rubber in there isnt severed

[CNY 90AccordLX]

I've just noticed my sisters 90LX has a vibration running through the whole car when it's at a complete stop and idaling. The car idals at about 6-700. Is that too low? The car is a manual not auto. And when I lightly touch the gas (in neutral) the vibration and noise goes away (800+ rpms).
I was going to buy a whole new complete set of tranny and motor mounts and bushings with energy suspension polyurethane inserts. Seeing as it all looks to be from 1990 still. it could use the new parts and hopfuly it fixs the vibration issue.
But if theirs anything else I should replace, I would like get it

[Grimsta]

I can get you Energy Suspension.
I think the idle spec is 800 plus or minus 50rpm. That vibration your feeling would be from a bad motor mount somewhere. The dog bones in the front go all the time, but so do the rears, and the rears are a big deal. Kinda tough to replace

[BIGDOM]

you have a vacuum leak, , it may not be a major leak, either that or ur throttle plate iand ports are gettin gummed up, there is a screw on the the T/B turn it untill the idle evens out