Misfire Issue during idle when cold, Misfire P0301 Options

[k-weaver]

So a couple of weeks ago I noticed the car had a rough idle when cold. It would slowly smooth itself out as it warmed up. Once warm there were no issues at all. About 2 weeks ago the car through a CEL P0301 which is misfire in Cylinder 1. Here is what i've tried:

- Swapped spark plugs in cyl 1 and 2. Turned off cel. CEL came back with same code, still having same issues. Plugs have maybe 35k on them (NGK iridium)
- Replaced dizzy cap and rotor. While in there i found oil leaking into the cap and then down and out of the cap. Replaced o-ring seal on dizzy and also the seal for the cap. CEL came back, same code same issue.

I'll be heading to carquest today to pickup an inline spark tester. I think this test will pass though because the car runs fine once its warm. Right now i'm leaning towards an injector issue. I just put a full tank of gas and added about 5oz of lucas injector cleaner, i don't have high expectations of this working though.

Any suggestions you guys can offer will be appreciated. Just to re-iterate...Car runs perfectly fine once warm. No power loss, no hesitation. It actually runs alot better with the injector cleaner, new cap and new rotor (smoother and improved throttle response). Only issue is its rough when cold. You can hear and feel the misfire.

[Special_Edy]

Use a compression tester, test it cold, hot and with a splash of oil inside the cylinder.

You can swap the injectors. Remove the 4 30mm nuts on the spark plug tubes then remove the valve cover. Use a wrench to remove the two bolts holding the fuel rail to the head.

[Galcobar]

Test the spark plug wires.

[k-weaver]

Got an update for you guys....when I got home last night I tested the spark plugs and they all appears to be firing the same. This morning I got in the car and started her up and there was a misfire like normal. I again tested the wire while the misfire was happening and this is what it looked like.

Flash flash flash...dead dead dead dead...flash flash flash flash...dead dead..flash..etc

So the problem appears to be spark related. Any thoughts on causes? Would seem weird for a plug wire to work when warm but not when cold. Plus the wires only have about 25-30k on them (ngk wires). Let me know what you guys think.

[glenn]

Test the spark plug wires.

I agree, this sounds exactly like the problems I had when my spark plug wires went bad.

For me it started when it was raining, and then it was with cold engine, and then all the time..

[Xander_X]

Tune up time!

[k-weaver]

Tune up time!

What exactly can I "tune up" that hasn't already been done? This is what i've ruled out 100% so far:

1.)Spark plugs
2.)Spark plug wires (used my old set for testing, exact same issue)
3.)Dizzy cap/rotor

At first I was thinking injector issue but after visually seeing intermittent spark in Cyl 1 I think I can rule that out and safely assume an ignition issue.

[Xander_X]

Probably a bad Ignitor ... there's a chance it's the coil. How long did this start AFTER you replaced the dizzy cap and rotor? Might be a defective one.

[k-weaver]

Probably a bad Ignitor ... there's a chance it's the coil. How long did this start AFTER you replaced the dizzy cap and rotor? Might be a defective one.

This was an issue prior to replacing. I replaced originally to try and fix the problem im currently having. Im thinking its either the igniter or the dizzy itself. Both of which are not cheap parts >.< any way to test either without replacing?

[hokuten3]

could be grounding. sounds impossible, but that's what happened to me.