Hi All,

Trying to diagnose a problem with my new daily. It's a 1991 EF (ED here in Australia) Civic, one owner, very low kilomotres, generally excellent condition.

It's got the standard, totally stock D15B4 motor in it (1.5 Twin Carb) and manual gearbox. It runs really well, still extremely fuel efficient and so far it's been reliable.

The issue is a fuel smell I get in the cabin, as well as smoke that I occasionally see coming from the back of the car. I notice it most after the car has been rolling in gear with no throttle, and then I start accelerating again. Example: a long downhill and an uphill on the otherside. The car is in 3rd or 4th rolling down the hill, and I’m not applying any throttle (so the car is essentially engine/compression braking to keep it from speeding up). As I get to the bottom and apply throttle to come up the hill again, I get a strong smell of fuel in the cabin.

This morning I had a similar thing where I was coming down a hill to an intersection. I was moving slowly with the car in second and no throttle down to the turn at the intersection. I stopped, put the car in first and as I took off I got a great big cloud of smoke out the back as I pulled away.

Can anyone tell me what might be causing this? I also get a fuel smell in the cabin while cruising on the motorway to work. Cruising anywhere from 80-110 km/h even when there’s hardly any load on the engine, I can smell it.

At first I thought the smell was from some fluid dropping onto the exhaust and burning, but I don’t think so anymore. I also thought it could be a leaking exhaust manifold or something, but the clouds out the back don’t seem normal. Perhaps it’s a malfuntioning emission system? I don’t know a lot about the funky electronically controlled carbs. I’ve got a couple of theories, but I’d love your input if possible.

Cheers.

 

I'm having this same problem except I don't have much smoke coming out of the tailpipe.

It's like you said, it's the worst when decelerating with no throttle.

I thought it was my 0w-30 synthetic oil, so I just changed to 10w-30 conventional today

Oh and I have a d16a6, fuel injection so it's possible it's not your carb system.

 

Hm - interesting. I think they're probably unrelated, we've just got a similar symptom with the in-cabin fuel smell. I'm certain someone on here would have solved this problem before!

 

yup i agree its a pretty hard problem

 

are you throwing any check engine codes?

 

could be a seal in the gas tank all of it goes to one side goin down the hill causing a spill but doesnt explain your smoke