bklynrx7

Hello everyone, I just recently purchased a 2006 Civic ex and this is my first post. The car has 65k on it and was maintained very well by the PO as far as I can tell. It runs great with just a few exceptions.

First of all the car seems to struggle when trying to rev past 2.5k rpms. There is a very noticeable hesitation accompanied by a vibration that is felt through the car. The boggy feeling and vibration go away once the rpms drop or if I give it more gas. Speed does not make a difference.

Additionally, I haven't been getting good gas mileage. I have been averaging 24mpg which is below what other people are reporting with similar mixed highway/city driving.

I changed the oil and cleaned the MAF so far. Im suspecting it may be an injector issue so I am going to try running a can of BG44k through the tank, then changing the plugs this weekend. Any other ideas or suggestions would be greatly appreciated.

mac25

Are there no codes? maybe your CEL is burnt out, scan it anyway.

Check all your plugs for spark/condition

If those are good then there most be a timing or fuel delivery issue.
(try renting a fuel pressure test kit).

If you have low fuel pressure the pump may no longer be able to flow efficiently at high demand.

bklynrx7

I don't have a CEL, but I will go get it scanned. I have an OBDII scanner that works on every car I have tried, including other hondas, but it doesn't work on this car. Apparently this specific scanner has issues with the Civic and the Fit.

If the bg44k and the new plugs don't do the trick I will test the fuel pressure and take it from there. Thanks.

ezone

Scanner needs to be new enough to work on CAN systems.

bklynrx7

It was a CAN scanner, and it worked on newer cars than this civic. Unfortunately it's a cheap Autel and it seems to have problems specifically with the civic and fit. Luckily, I had an even cheaper Bluetooth ODBII dongle laying around that doesn't work on my Audis but works perfectly on this civic. I used the Torque app and scanned it finding no issues. I also was able to read my fuel trims, which I was asked for on another forum, though I don't know what to make of this info yet.

As far as the hesitation goes I have an update. While I was waiting on the bg44k and new plugs to come in the mail, I continued to drive it and simply rev into and past the problematic range once a trip or so. The hesitation and roughness gradually diminished and the problem is basically resolved now. I just put the bg44k in and I will see if this clears it up entirely. Im assuming there was just buildup from years of only being driven in traffic and the legendary "italian tune-up" did the trick.

I haven't measured mpg yet, I am going to wait till the BG44k is out of the tank and I get the new plugs in.

ezone

Does this hesitation issue only happen once per trip?
About the same place each time it happens?
(or roughly the same time from startup, or any clue that makes this a predictable event)

bklynrx7

No, the hesitation was happening any time I would try to rev past 2500 rpms under load. It didn't matter if I had been driving 10 minutes or 2 hours. I meant to say that I purposely revved into and past this problem area once a trip or so in an attempt to resolve it.