2001 Accent cylinders misfiring - Fuel Economy, Hypermiling, EcoModding News and Forum

jesse.rizzo · 07-10-2010, 04:19 PM

My 2001 Hyundai Accent very suddenly developed some problems last night. Major loss of power when under heavy load. The scangauge reports cylinders 1 and 4 are misfiring. I changed the spark plugs and the problem persists. The spark plug wires look fine. I also put some injector cleaner in, but I haven't driven it enough for that to do anything yet. Any other suggestions or thoughts? Thanks.

gone-ot · 07-10-2010, 04:34 PM

...did you also check the spark coil(s) for those two cylinders?

...getting a good "hot" spark at each sparkplug?

robchalmers · 07-10-2010, 05:18 PM

as above ^

also check the fuel injector wires, and compression on those cylinders

jesse.rizzo · 07-10-2010, 06:40 PM

How do I check the coil? Just visually, or is there a tool to test it? The same coil controls both the misbehaving cylinders. So that's hopeful.

gone-ot · 07-10-2010, 11:28 PM

Quote:

Originally Posted by jesse.rizzo

How do I check the coil?

...pull one of the offending sparkplug wires and lightly position it on top of that spark plug, then start the car and then look at the plug wire and plug.

...if there are "sparks" flying, the coil HAS to be OK, if there are NO sparks, shut the engine off, replace that plug wire and repeat the process on the other spark plug...if NO spark at both positions, you've just confirmed its a bad coil.

bestclimb · 07-11-2010, 02:43 AM

are the plugs on the misfiring cylinders wet at all?

robchalmers · 07-11-2010, 05:06 AM

if there is the plug wires are simliar length, identify the two from the good clyinders with a ring of contrastin electrical tape. then try swaping one with a bad one. if the mis cylinder starts working and vice versa its the plug wires. if it make no difference its the coil.

Are the spark plug nipples tight? (

)

jesse.rizzo · 07-11-2010, 04:53 PM

Thanks for suggestions all. It did turn out to be a bad coil. I conducted the test as Old Tele man described, and sure enough sparks were flying on the good coil and not on the bad one. I managed to replace the coil in 45 minutes, which for me and my limited mechanical skill is incredible, and all is well again. So thank you very much everyone.

-Jesse

redline5th · 07-20-2010, 03:11 PM

Sweet! I just learned some stuff about coils. I've only worked on distributor cars.