Stumbled on a vacuum leak fix for a Civic misfire that had me stumped

I had a Civic come in with a random misfire that only happened under load, like going up a hill. The owner was sure it was a bad coil, but after swapping them, the trouble code moved. I checked the spark plugs and they looked fine, then fuel pressure was normal too. I was stuck until I grabbed some carb cleaner and sprayed it around the vacuum lines. The engine rpm jumped when I hit a spot near the intake manifold. Found a tiny crack in a hose that only leaked when the engine worked hard. Replaced that one hose and the misfire cleared right up. It's wild how a small leak can cause such a headache, anyone else deal with vacuum issues like this?

2 comments

2 Comments

ben_nguyen331d ago

Of course it was something stupid like a tiny crack.

blakeallen1d ago

My old phone stopped working last year from a hairline crack near the charging port. I totally get what you mean, @ben_nguyen33, I used to think those little things weren't a big deal. That one totally changed my mind!