/o/ - Auto

>Replace spark plugs with NGK Double Platinums
in my experience, copper core plugs work better

also have you done a compression test?

>>1705

Compression is fine, but still misfiring. I'm thinking it might be the Leads given that it's the only thing ignition wise I haven't replaced.

The NGKs are alright, but what makes you suggest copper cores? I'd like to know. Are they better for spark strength?

>>1707
>The NGKs are alright, but what makes you suggest copper cores? I'd like to know. Are they better for spark strength?

yes, but they don't last as long, and i have personally had a misfire issue that was caused by bad platinum spark plugs (on an 350 with HEI ignition), although it may just depend on the car

>>1708

Well I only put them in a month ago or so. Besides taking it straight to a Mech what else would you suggest?

>>1708

Also- could my timing belt/chain be worn?

>>1709
>>1710
try swapping spark plug wires around, other than that idk

as for the timing chain, it could be loose/worn but i dont think that would cause a missfire, and you could adjust timing to compensate even if it is worn

>>1711
could also be a bad injector on that cyl

Vacuum leak, do/get a smoke test done.

>Constant misfiring

First: Do you know which cylinder is missing? If not, start engine, then disconnect one injector at a time until you disconnect the one that doesn't make it run worse.

Now that you know the where, time to find out the how. You say you've replaced everything but the spark leads? well swap that cylinder's with another, repeat the injector disconnect test. If the mis has moved, it's the lead.

If it's still on the same cylinder, this time move the injector to another cylinder.

Repeat disconnect test.

If the mis has followed the injector, there's your problem, if it's still on the same cylinder, then you're left with engine internals.

If compression in that cylinder is in line with the others, I would first spray the intake gasket with brake cleaner on that cylinder's port to see if it starts running well. A failed intake gasket could be altering the mixture too far on that cylinder, letting the leak suck up combustible brake cleaner would make it run well momentarily.

If it's not the intake gasket, I'd look into carbon deposits on the intake valves.

>>1712
This. You could possibly have flooding issues or no fuel at all in a cylinder. I don't know as much as I used to ever since I joined the glow plug mustard race, so I don't think I could be a very big help right now.

check fuel pressure between the fuel line and the rail
check continuity of plug wires against manufacturers spec

Mass air flow meter, coolant temp sensor, anything else cheap that comes to mind.