CYLINDER 1 MISFIRE ON COLD START

[PNWEddieBauer]

New member here. I have a 2004 Expy 5.4L Triton Eddie Bauer Edition.

Lately, I've been getting a cylinder 1 misfire ONLY on a cold start. This lasts anywhere from 20-30 seconds, then the car runs like normal.

Things I have tried:

New spark plug in Cylinder 1
New Ignition Coil for Cylinder 1

These did not fix the issue.

I have a new fuel injector on the way as I think it could be that next, but does anybody else have any ideas? If it's not the fuel injector in cylinder 1, I have no idea what it could be from there. Any and all advice is appreciated.

 

[whtbronco]

It could be a connector or wire issue with any of the items you mentioned or carbon build up in the combustion chamber.

 

[BlackCoffee]

Cylinder 1 is notorious for being a indicator of a bad head gasket. Next time the engine is cold, pull the plug and see if there is coolant on it. When the engine cools, if the gasket is starting to leak, it lets coolant in until and causes a misfire. Are you losing coolant? That would be another indicator.

 

[blacktail]

Going to resurrect this thread because I have a similar issue:

1. I am very suddenly experiencing misfires, rough idle and driving
2. Forscan tells me it is cylinder 1, seems like that cylinder is barely firing at all given the 1000 plus misfires it recorded in the few minute drive home
3. Pulled the ignition coil and boot, lots of liquid in the spark plug hole ~1/2" to 1" deep
4. Checked around above the hole examining coolant lines/t connection and did not see any indication of leaking
5. Engine oil looks fine, no milkshake
6. Dried out spark plug hole, packed dielectric grease in the boot and replaced
7. Now, no misfires and engine is running fine

Any thoughts where this liquid may have come from? It didn't really smell strongly of coolant.

It has been snowy/icy here lately, so I'm wondering if a random chunk of ice found its way on top of the boot and melted...?

I've also had an issue in this cold weather with rear washer fluid lines popping off, so maybe some washer fluid leaked in the engine compartment and wound up pooling in cylinder 1? The positioning seems odd for that though, and the fluid hasn't been used that way for days with the vehicle being used extensively since then.

 

[whtbronco]

I'd say it is not washer fluid unless it's spraying since the washer line doesn't run over the front of the engine. Old coolant, the factory yellow stuff especially won't smell much like traditional green coolant. I'm thinking it's got to be a coolant leak over or next to the cylinder 1. Could be a hose, connection or maybe even the intake manifold since the coolant crossover is around cylinder 1.

If the coil boots are old you'll get a better seal from a new one and some dielectric grease around the seal where it goes into the plug recess will help keep most of the fluid out as a temporary help. Don't forget a bit of dielectric grease spread lightly around the inside of the plug end of the boot to keep it from sticking to the plug ceramic.

The coil boots are in stock at my local dealer for $8 each.

 

[BigRed2004]

@PNWEddieBauer, I would consider getting some Sea Foam Spray and trying that out to help remove carbon build up. That could be a problem as mentioned by @whtbronco.

@blacktail, Cylinder one sits below the crossover tube on the intake manifold. This section is notorious for leaking due to the plastic breaking down. That would be my guess on how any liquid got in the spark plug well. You might see some pooling in the valley under the intake manifold if this has been going on long enough. Also check around the intake manifold under the crossover tube and see if anything looks wet.

 

[blacktail]

Been driving around over the past few days, as well as letting the warm engine idle with the hood popped to observe. Haven't seen any more liquid or indication of leaks. Been looking at the crossover tube, intake manifold gaskets, coolant hoses, etc... Totally dry.

Interestingly, there is lots of discussion on F150 forums regarding mystery water filling the spark plug wells, but that seems to be related to leaky cowls, which would not be an issue with my expy.

Strange!

 

[BigRed2004]

Strange indeed. Well at least it hasn’t returned. But if it does, do your best to look all over for fresh trails of liquid. Maybe even consider taking a photo of the area while it’s dry to use for comparison later to see if you can spot something.