Anyone know what this sound means? It sounds like there's an occasional misfire. I just failed aircare (smog test) and my fuel economy has started to go downhill.

http://walk.darktech.org:8444/yotatech/IMG_0294.MOV

cheers

 

The best thing to do is start with the basic stuff, do a complete tune up, plugs, plug wires, cap/rotor, and fuel filter. Also make sure the the valves and timing are properly adjusted. Another thing to check is the oxygen sensor, if its original or it has a lot of miles on it, then replace it.

 

The video hasn't loaded for me yet, but do NOT start with a tune up to FIX a running problem. A tune-up is maintenance, not repair. You need to START with proper diagnosis, unless you just want to waste money and time. I will be back once I watch the video.

 

As always, check that compression first. Sounds a lot like mine did when it was running on 3 cylinders. If the compression is good on all the cylinders, then you might want to look into the tune-up. I would start with valve adjustment first, then work my way through.

Let us know what you find.

 

Check for a dead valve, dollar bill test (or 5 dollar bill for us candians haha!)

 

My distributor was shot. I replaced it and my fuel economy is much better at 8.5-9.5km/l (20-22mpg). Before I was only getting about 400km to 55l. The air gap was gone and the rotor was just making contact w/ cap points and scraping them. Eventually started making a groaning noise that I thought was my waterpump. Shaft felt nice and tight and straight and bearings were fine... I tried adjusting the gap, but it still had a bit of misfire. Bought a used one for $20 and road trips are much, much more enjoyable.

Compression was fine. I couldn't really tell if dollar bill test was sucking it in on misfire, but it's definitely not now...