Idling-misfire-stalling issue

[SpeedySub]

I have an issue when my car is idling sometimes (N/A 2.5 auto). It seems to miss or feels like its only running on 3 cylinders. It doesn't do it all the time and seems to be worse when warm.

I did flatten the battery over the weekend, but started it with the misses car. It runs rough and seems to hunt for idle when not misfiring and seems to be a little better when in neutral instead of drive. When in drive it runs rough and sometimes dies. What are the best places to start looking?

Coil pack? - if so hows the best way to check - My multmeter is packed some where in storage at the moment.

Plugs?

Ignition leads?

Vacuum hoses?

anything else.

Also I have read that oil on the plug leads at the head can cause misfires- I do have some oil leaking around one of the plugs, but has been like this before and never caused an issue.

At this point my budget and time is severely limited until we buy a new house and finish moving.

Edited June 9, 2016 by SpeedySub

[Rosssub]

Be worth checking your plugs out. Could also blast the lead head that's covered in oil with brake cleaner to see if it makes a difference, or just pull that lead to see if the idle/miss changes at all.

Could be a dirty idle control valve, give it a good clean out with carby cleaner etc.

Or a vac leak somewhere. If ether (starting fluid) is sprayed near a vac leak the fluid will be sucked in and the idle will change. Or do a good old boost leak (pressure) test, by blocking the intake off at the AFM:

Then pump 10-15psi into the manifold with an air compressor. Any leaks will hiss and be obvious:

[SpeedySub]

Will have to look at the weekend to all those things you've mentioned.

It didn't throw a CEL yet.

Anyway to tell if could pack? without multimeter? or is that the same as pulling the lead?

[pedro]

have you charged the battery ?

Might run better with it fully charged..

[SpeedySub]

 pedro said:

have you charged the battery ?

Might run better with it fully charged..

Haven't charged it with a external charger. Only took it for a long drive to get it charged again. It started fine since once charged. But another avenue to look at.

[Rosssub]

 SpeedySub said:

Will have to look at the weekend to all those things you've mentioned.

It didn't throw a CEL yet.

Anyway to tell if could pack? without multimeter? or is that the same as pulling the lead?

Not really, other than swapping it out for a known good one or visually checking for cracks in the coil body. Here's the resistance specs/testing procedure for the older separate ignitor coil packs:

http://www.main.experiencetherave.com/subaru_manual_scans/FSM_Scans/coilpacktest.jpg

For ignition trouble/misfires pulling leads one at a time identifies which cylinder is playing up. Once the plugs are checked, swapping leads between cylinders to see if the problem cylinder changes can identify a bad lead.

[SpeedySub]

 Rosssub said:

Not really, other than swapping it out for a known good one or visually checking for cracks in the coil body. Here's the resistance specs/testing procedure for the older separate ignitor coil packs:

http://www.main.experiencetherave.com/subaru_manual_scans/FSM_Scans/coilpacktest.jpg

For ignition trouble/misfires pulling leads one at a time identifies which cylinder is playing up. Once the plugs are checked, swapping leads between cylinders to see if the problem cylinder changes can identify a bad lead.

Awesome. Thanks will check the leads tonight. Thats something I can do. Is there any way to run a 3 pin coil pack on a 4 pin plug? Im assuming not. (I accidentally brought a brand new 3 pin one cause I didn't check mine first)

[Rosssub]

 SpeedySub said:

Is there any way to run a 3 pin coil pack on a 4 pin plug? Im assuming not. (I accidentally brought a brand new 3 pin one cause I didn't check mine first)

Nah, not without loom changes and wiring in an external ignitor. The newer 4 pin coils have the ignitor built in.

[SpeedySub]

Last weekend I ran upper engine cleaner through, cleaned all oil from around the lead and gave all the leads a clean to but only managed to get one plug out before it rained, it was all good. So I emoved the idle control valve tonight. It looks like its never been cleaned. Gave it a good clean. So far seems to idle smoother. Will see how well it does tomorrow.