I am helping a buddy out with his new project, he just bought a 1991 Civic EF Hatchback.

Somehow it's leaking oil from the throttle body, which seems really odd. We traced the oil to what looks like some sort of filter that bolts onto the throttle body.

If you're looking at the engine bay, it's on the right side of the throttle body, it bolts on with 2 bolts, it seems like there should be a gasket there but there isn't.

Anyone have a diagram of a throttle body? I could show you, otherwise I have to wait til I get home to take a picture.

Anyways, it's somehow leaking oil, any ideas how that's possible?

 

is this an mpfi car or a dpfi car?

 

I am not sure, he has the D15B1 I believe.

 

left or right? should be right..

 

The one on the right, the part in question is not visible in this picture though, it's directly under the bottom-right portion of the black box that sits on top.

The part connects up to a metal part with metal hosing, almost looks like a fuel filter, with bends in the metal piping?

I get off work in an hour, can update then.

He's doing a B16 swap soon, so we're not sure if we should really worry.

 

The only way oil could get there is if it is in the vacuum system, which means that either the car was really overfilled with oil at some point, or the pcv system is not working. I wouldn't really worry about it though, if there is a swap coming in the future. maybe change the pcv valve if that hasn't been done recently, but i wouldnt worry about it more than that.

 

I think he just overfilled the oil, we are going to check the PCV valve today.

The part in question is where the fuel line connects up to the metal part that bolts onto the throttle body, is this his fuel filter or what?

He stipped the bolt on this yesterday by accident, so we have to use a bolt extractor now.

 

pcv valve is bad...!!!

 

There is no gasket on the fuel filter where it bolts up to the carb, shouldn't there be one there?

 

What is the throttle body on the right? is it fuel injection or a carb? I just picked up a 1990 hatch and was told the motor was swapped with the same motor, a d15b1, it looks a lot like a carb, but its the one on the right in the above picture. Also does anyone know what fuel pressure I need? (the tank and pump are gone...not sure why)

Any help would be awesome!

 

The one on the right is a Dual Point Fuel Injection(DPFI) setup, It was used on base model civics from '88-'91, Its basically the link between modern fuel injection and carburetion, I believe just about all car manufactureres used it for a few years in the '80s on most models. The DPFI should take the same pressure as MPFI, and your fuel filter is not on the throttle body, its on the firewall. follow the fuel line to the fire wall, and theres a small black metal canister, with two fuel lines on top.

 

I dont have my old DPFI manifold handy to look at, but the only thing I can remember being on the right side below the top section with bent metal tube was the EACV which would only have coolant and air going through it. I belive the only place where engine oil could really make it into the intake manifold would be through the PCV which screws into the manifold between the throttle body and the head on cylinder three's runner, and has a hose that connects down on the back of the block, and the line that goes from the valve cover to the intake tube, but thats up higher and to the left of the top piece.