Cylinder 4 Misfire

[mrpeanut]

Sorry if this is a bit truncated, but I just had a long descriptive post ready, and then there was some kind of error and the whole thing was lost. I've been working on this for a bit now, and I'm sure somebody knows the answer. My '98 ZX2 has coded a "Cylinder 4 Misfire", and has been hesititing and having an obvious dead miss during accelleration, and anytime you try to get some power out of it. New plugs help for a bit, but so does just cleaning the plugs. They aren't getting carbed up though. Looking through past posts for guidance I've gone ahead and done a few little things, but I don't want to head down a beaten path and find out it's just plain wrong when I could have asked directions, and gone the right way. So Please help me.

I've checked for Vacuum leaks, and replaced the PCV Valve.
I've cleaned the MAF sensor (needed to be done anyways)
I've checked the fuel filter
I've checked the wires
Changed the plugs (always helps for a bit)
Ran without the VCT (unplugged the Cam Position Sensor)
Checked the fuel injectors
Probably done a few other things too, but I can't think of them now.

***
New Symptom today (July 26, 2007). Stopped at my destination, and the thing nearly stalled. RPM went down to about 300, and fluctuated back to 1100. Did this for a minute or two, and I finally just shut it off.

I'm also getting a fair bit of pressure under the valve cover. Never knew that to be a good thing (Hopefully I'm wrong and it doesn't mean anything)

[mrpeanut]

Well
just to update my list of complaints.
I have a blown headgasket I think. Getting a lot of blowby. Hopefully when I'm through with this one we'll be on the road again.

[mrpeanut]

Alrighty then. I'm going to delve in, and tear down my engine. 270,000 km on this thing, and I wish I didn't have to, but not really an option at this point. If anybody has the torque specs, and pattern for tightening everything. I'm desperate... Can't you tell. A little help here would go a long way, and I'd really appreciate it.

[mrpeanut]

Well. It's not a head gasket problem. Silly car is getting between 180-190 lbs of compression on all four cylinders. What I thought was blow by was in fact vacuum in the engine, so I'm still looking for a solution to this ongoing pain in my rear. I'll just keep posting things hear, talking to myself , and hopefully someone is going to chime in at some point with a magical solution.

Also tested the fuel pressure. It holds steady at 19 lbs. Vacuum lines build presssure to about 20 lbs, and hold steady.

[Selectron]

Hi mrpeanut, and welcome to the forum. I'll just say right now that I can't help you with this, because my expertise is solely with matters electronic and electrical but I don't like to see you sitting here just talking to yourself day after day! You might want to summarise what you've found so far and post again over in the Engineering & Technical forum, which is for general technical matters but isn't manufacturer-specific; maybe somebody there might recognise the problem if it's a generic issue. I drive a UK diesel Escort so I spend most of my time on the Escort forum; sometimes ZX2 questions get posted in there but they tend not to get too much of a response so I'm guessing that the ZX2 engine differs a fair bit from the standard Escort. I think your best chance of a response would be the Engineering & Technical forum. If you do start a new thread over there, I would suggest that you also keep this one updated because somebody may stop by who can offer some help. Anybody got any input on this one? Good luck, and I hope you find the resolution soon.

[mrpeanut]

Alright, the car seems to be working now. All the tests showed the plug wires working fine, but I replaced them yesterday anyways, and it seems to have made a huge difference. Kind of weird 'cause the resistance was normal on them, and you could dump a gallon of water on them, ect. Anyways, still doesn't seem to be quite the same as it was before all this, but I'll take what I've got for now, and wait for a new code to pop up.

[bfd637]

i have a 2001 ford escort zx2 2.0 auto.miss firing on 2 and 4 cyclinders.change plugs wiring coil only thing i havent is injectors and vacum.has 168000 miles.timing has been change to.could u please send me in right direction.thank u

[bmenzing]

Good to hear that plug and wire replacement seems to have solved your problem. If it creeps up again, I advise you to replace the coil pack. The part cost $25 - $35 dollars and is EXTREMELY simple to install. Spraying some WD-40 on the bolts before you start will make the job still easier. The coil pack is easy to get to. Replacement should take no longer than 15 minutes. Some cars have a separate coil for each plug, but the ZX2 coil pack services all 4 cylinders. There are several youtube video's on the web that document the process. The one in the link below is very helpful. I've done a couple of these and they were easy to do. Good Luck! https://www.youtube.com/watch?v=T6kOUQiSjBI