po302 misfire #2, mystery wire

[jgt]

the mystery wire:

first freeze frame

then freeze frame after plug wires and cleanings

hi all-
Looking for a little guidance here. I got a 1999 2.5L 146,000 miles. Got a flashing chk engine light and rough running. Code: p0302 misfire #2 cylinder. also does anyone know what this gray wire/hose is? There is no wire in it, but looks too small to be a hose. There's no vacuum when the engine is running. Sorry if that's a stupid question. Anyhow,

things I've changed
fuel filter (filthy)
breather hose (cracked)
air filter
plug wires

things I've cleaned
MAF
Throttle body
PCV valve

running as bad as ever and code keeps coming up. Checked the sparked plugs on #2 and they looked good. Never changed them as it looks like a royal PITA to get to all of them. Will change #2 spark plugs tomorrow, but doubt that will clear it up. Any suggestions?

Next: plugs, then coil pack, the ??injector cleaner?

 

[ricardo93]

That looks like it would be a vac line, check and see if theres any vacuum opening that are the same size as that line

 

[jgt]

vac line heater control valve

http://www.youtube.com/watch?v=7tSFPSY19MI

found on this link.

reconnected it, now AC runs worse than ever.

changed plugs #2 (cracked porcelain on one of them). Not much help. Runs super rough still, awaiting the CEL to re appear. would a bad ignition coil cause the plug to crack like that? And if the coil is bad, will it throw a code? thanks

 

[ricardo93]

No idea about that, but changing all the plugs is better than just 2 and if you have too take it to a shop so they can check your timing, since its edis

 

[NIPs]

This is a 2.5 and what im about to tell u is extremely important, I have the same engine and what destroyed my engine was 1 wire im not hundred percent sure if this will help but u need to know this, ur maf, fuel injectors, iac, and shift solenoids run off of 1 wire its a 12volt wire, from ur maf u will see a thick red wire follow that should come to your iac then splits going to ur injectors and shift solenoid, check this wire to make sure there is no breaks, mine kinda melted, I would get intermittent codes for all 4 of those components, by the time I looked into it it was 2 late, becuz the transmission solenoid wasn't getting enough power it failed to shift as I was getting on the freeway which eventually led to a spun bearing

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[NIPs]

O and that Gray hose is nothing my buddys is like That and so was mine

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[jgt]

thanks for the tips. I checked the red 12v wire, it's still all wrapped up in the housing, so I assume it's not melted through. I found the gray vac hose placement. It's the Max a/c vac line, rehooked it up.

truck still rough running, only after warmed up though. Especially worse with AC on. Checked resistance on both coils and cleaned the grounds. All primary at .4 and secondaries at 13.4k, so within spec. They are original motorcraft ones.

 

[Mark_88]

The doors on your heater box are all controlled by vacuum...it might be a vacuum leak, but someone recently posted that they had the exact same problem and worse with A/C on...it was in the Urgent help needed forum near the top...search that for things like "2.5 rough running" or similar...it was only last month so it should be near the top...

It may actually be in this group but I can't remember...and I can't remember what the fix was, but I suggested the same thing...check the vacuum lines first though...there are about five of them that come in through the firewall below the heater box...I know it was recently posted though...I will try searching for you and will post back if I find it...