Weird cylinder 4 missfire
 

I have a 98 ek hatch y7 5spd and the check engine light came on. Only read cylinder 4 missfire. New spark plugs and wires. Checked distributor, replaced inside plastic cover (other was broke). Still on. Holds coolant beautifuly and doesn't burn oil badly. starts to burn more halfway through to next oil change. Header had a crack and so did the exhaust mid piping. Replaced that. Throw out bearing went out replaced that. Now it comes on and off like everyday.

Oh forgot found out my car has a leak at the rubber like fuel hose. I drip fuel if I filll up and park. I was thinking that could be causing it. But I cannot find a replacement.

sounds like a job for the tech section

which hose are you talking about that's leaking fuel? the main hose from the firewall to the fuel rail or what?

Fuel filler hose. The one that connects to the gas tank.

The filler neck leaking will not cause a cylinder misfire. That would cause an evaporative emissions leak detected code.

The tricky part about individual cylinder misfires is that there are many many things that can cause them. You've replaced 99% of the things I tell people to check. Only other possibility is a semi clogged fuel injector.

If I had the problem I would go buy a can of sea foam and put half in the gas tank and suck the other half up through a vacuum hose. Might use the brake master hose. Give it about a tank of gas to see if that's worked.

If the issue still persists, I would swap # 4 injector with another on the car and see if the misfire travels to where ever you put it.

Sent from my SCH-I605 using Tapatalk

I've been putting lucas in my gas tank. I'll try that and post an update if it worked.

Yes I would check for a leaking injector, cracking around seal or getting stuck. I would also boroscope cylinder to see whats going on in there and to also see if you might have a cracked valve.

Sent from my SGH-T989 using Tapatalk