That could be a fuel pump, fuel injector, fuel rail, or fuel filter problem. Like tankard stated earlier, I would look at the charcoal canister and see if the hoses are actually going somewhere. I heard that that little canister being unplugged lowers fuel economy below 20mpg or so!

 

Ok, I'm at work right now and I ran out and saw that that area is a mess. one tube was completly disconnected from something, but now that I look at my haynes manual I think it might have been the drain tube coming off of the filter. But its very possible I have a leak, I looked real carefully in the engine bay, and on the passenger side right around the charcoal filter there seems to be a lot of moisture all over, everything kinda looks wet, and on the driver side of the engine everything is bone dry. Some small metal pipes had a lot of rust on them and seemed wet. A fuel leak would easily explain such awful mileage. Hopefully there is enough light when I get home to really check it out. Any easy ways of fixing a pipe that leaks? like a type of tape?

 

ok, I went out and looked again, the hose that is lose coming off of the filter is supposed to be going to a 3 way and to the dashpot control valve. where is it supossed to go is plugged by a screw, so I have no idea why that was done. Hose that is lost is thick and covered with red nylon threading of some type. Hopefully I will be able to see what is going on with the engine running.

 

well I check for leaks, couldn't find a thing.
So I must just be running really really rich.
Everything seems hooked up fine so far, did take a picture:

 

The purpose of the O2 sensor is to measure rich or lean and adjust the a/f ratio accordingly so yea, if its unhooked or broken, your fuel economy will be shot...

Anyways here is a pic to help you find where that hose is supposed to go...




Comparing my pic with yours, it looks like some of your hoses are installed incorrectly... Ofcourse it may just be because itsa different engine...

 

I've ordered a new o2 sensor, so hopefully that will help some. About the hoses being wrong, I have no idea about them. I have tried looking at a bunch of different manuals and different sites, but its hard to find anything that deals with the 91 crx with a b18a in it. I will try a few things out, and if I don't have any luck might take it to the honda dealership here and see if they can help me.

 

Here are a few more pictures if it helps anyone to tell me if the hoses are wrong for sure.

 

i'll try to snap some photos of my friend's b18a and where his hoses go, i probably wont see him til sunday though so it'll be awhile still.

BTW i don't mean to thread hijack but is this normal? that crescent cut in the butterfly valve?

 

Um maybe because CRXs didnt come with B18s? You need a Integra manual if you are wanting to know about the hose layouts or any other info about the motor.

 

Yea, I ordered a haynes for the integra 90-93. Hopefully with that and all the other stuff I have I will be able to figure it all out.