I just swapped in a B18C motor and new type r tranny into my 1993 HB Si. Before the swap the car had zero vibration at idle and ran silky smooth. Now the whole car has a vibration to it while at idle. It goes away if you rev it past 3k. Think cell phone vibration but double it. Is this common with Civic hb B18C swaps? I have all new engine and tranny mounts in place, and the PS pump pulley is new and not bent. Not sure what could be causing it.

Thank you all

 

What kind of mounts did you use? Meaning what material?

 

In addition to the mounts question, what ECU are you using? Did you set ignition timing properly? What's your idle speed? For that much vibration, it sounds like a combination of mounts stiffer than you're used to and an engine that isn't running well.

 

They are polyurethane. That's why right? Since it's such a hard material the mounts don't absorb the engine vibration like rubber mounts do.

 

I'm using the the GSR USDM ECU. No tuning has been performed on the ECU. It's factory. No engine codes are being thrown. I'm thinking I went too extreme when choosing the motor mounts. I needs to choose something that has more give.

 

There are different versions of polyurethane mounts. Exactly what did you get? Still want to know if you've set ignition timing properly.

 

I installed the Innovative mounts.
60A: Recommended for street use and stock to mild motors. Red Urethane.


Honestly the engine has not been tuned, so whatever it was set at in Japan (JDM engine) is what I have now. She idles at 750-850. I'll take it to Honda to get it tuned before I go spending more money on mounts. If tuning does not help, I was told I could install the stock GSR Integra rubber mounts. I'm hoping that rubber mounts will solve the issue.

 

That's...no, you seem confused. There's a difference between a tune, and a tune up. A dealership isn't going to tune your car. They might give your car a tune up, but they'll also overcharge you out the *** for extremely simple stuff that you should be more than capable of doing yourself. 60a mounts will be stiffer than stock, but should not be bad.

You have also failed to tell us if you've set ignition timing after I've asked twice now. If you continue to make people repeat themselves, you aren't going to get very far very quickly.

 

Sorry. Used the wrong terms. I meant tune up. So are you saying going to the factory rubber mounts will not help me?

I did not set the ignition timing. It has been left as is.

 

Buy/borrow/rent a timing light, and set your ignition timing properly for starters. If you want a tune up done, save yourself a few hundred dollars and do it yourself. NGK plugs and wires, OEM fuel filter, and if you really want to go the extra mile, send your injectors off to https://www.injectorrx.com for a professional cleaning. Going back to OEM mounts will help, but it will be negligible compared to 60A mounts, which are basically as soft as you can get in the realm of poly.

 

I have the same mounts in my car. Get used to it for about 1000 miles.