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Misfire and Lean Bank

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CapnGnarly

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Discussion starter · #1 ·
Current conditions:
P0304 - Cylinder #4 misfire
Bank 1 too lean (not sure of the code exactly, the guy at the shop just read it to me)

Running very rough (the cylinder isn't even firing at all). It's happened once before, but was fixed. Last time it was a problem with a leaking valve cover letting oil into the spark plug seat and filling the cylinder with oil from the top down. Cleaned out the oil, replaced all spark plugs, and put a new valve cover gasket on it, and she was running fine.

The weather has also become extremely snowy lately. I am running a CAI, but I've run it in more snow than this and it's been fine.

The misfire is always preset and is not affected by RPM's. It's most noticable at low RPM's (idle in particular), as the whole motor shakes from it being so out of balance.

Any ideas, throw 'em out there. I'd also like to know specifically which cylinder is #4 (are they numbered left to right or in firing order?), as that will help me locate the issue more.
 
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#3 ·
Well in your case it can only be a couple things. The Plug is bad, the wire is bad, or like above the coil or pigtail to it is bad. One of those or a combination of them. Which is also the culprit for the DTC . Not firing and too lean...
 
Discussion starter · #4 ·
Checked the wiring, all good there.

What are your thoughts on it being a vacuum leak? A local friend of mine suggested the lean might be coming from a leaky intake manifold gasket, which is then causing the misfire?

Also, if it's not a vacuum leak, would it be worth it to just buy some new boots for the coils and see if that remedies it? I know it's not as likely, but having a corroded or dirty boot can lead to a loss of spark, correct?
 
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#5 ·
Well, you have the coil on plugs. On FF Mobile, I cant see what car your driving. I wish we could change that!! Any how I dont think the COP go bad that often. Some one with more experience with them will chime in. But Yes It could be an intake leak. Any unmetered air getting past the MAF will make the engine run badly .
 
Discussion starter · #6 ·
2.3L Duratec PZEV w/ FSWerks CAI and Focus Central 65mm TB. No other engine mods other than copper instead of platinum plugs, but I've been doing that since day one and wouldn't think to look there.

I should mention that this has been happening over two sets of plugs, just to eliminate that possibility.

The shop I called said they've *never* replaced the COP's on a Focus, but have needed to do some IM maintenance before, so their guess is IM. I'm split on the possibility. IM makes sense, the car has almost 89k on it and is 7 years old now. A gasket going bad is just about the right time. But also with all the salt, snow, and cold, wiring could have gotten messed up, and the fact that this is only happening in the winter points me in that direction.

It's a bit of $$ either way, so I'm just trying to decide which road to run down so I don't end up chasing both.
 
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#7 ·
Ok, I've replaced the boots on my COPs before, and cleared up a running problem that some people might call a misfire or stumble. I found corrosion on the spring which is inside the boot and makes the connection between the boot and the top of the plug. Boots can be had anywhere for about $7, I ordered mine from RockAuto because I needed some other stuff, and boot kits were like $5 ea.

Now have some grease handy- high temp grease- anything but moly or brake parts grease which is part moly. Clean off the corrosion if you find it, and put grease on that connection to prevent future corrosion. Moly is the only grease I know of that conducts electricity. I've been using axle and wheel bearing grease on electrical connections long before they marketed "dielectric" grease.

Now is that your problem? Probably not IMO. What does that plug look like? Does changing the plug alleviate the problem for a short time? Please change it, and only it, with a standard plug not platinum or iridium, for the time being. Why? Those don't build up deposits- which is good for long life, but horrible for diagnostics. If you do see deposits on a plug that was platinum or iridium- please make a note of the type, color, and condition of the deposits, like this: white, fluffy, dry deposits-- or, Black, caked, wet deposits.

As far as the lean code goes- ignore that until you get the misfire repaired.

One more check- turn the key to on, back to off, and repeat that 2x, now go pull the #4 plug again, and see if it's wet. If it's not wet and doesn't smell like fuel, then check #3, if #3 is wet and smells like fuel- then you should start tracing down injector problems on #4. Of course, check to be sure it's plugged in.

I'll try to keep an eye on this to help you along. Anything else you want to add like- I ran 100hp shot of nitrous every week until last week- would be helpful.

One last thing- the freaking intake manifold gasket from most parts stores is not even $30. It's a molded gasket- uber simple to replace. The intake manifold is on the front of the engine compartment- uber simple. A novice with a manual could likely do it in a day with quite a few beer breaks. Just be sure to have some extra parts, I'd definitely have a new PCV hose (small rubber molded job) to replace it when I removed the manifold. Another thing to check is the tumble flap motor that is just under the TB. Just make sure that it's little arm is still attached. I've heard that the cheap clip breaks sometimes.
 
#8 ·
Whoa I take that back- your tumble flap is controlled by a vacuum diaphragm- so it's completely different. I'd think the gasket was the same though. I'll go check- watch an 04 have like a $50 gasket- just my luck.

It's the same, if you can get it for $15 from RockAuto, you can get it around town for less than $30. It looks the same to me= 4 D shaped molded gaskets.
 
Discussion starter · #9 ·
+rep for the huge help, man.

I'm 99.99% sure there's not a problem with the plugs. I've seen this issue across two full changes of plugs and never saw corrosion or damage on any of them.

I'm going to start by seeing if there's anything in the boot when I get some time later on. I have an inkling it's there. Maybe it's just a hope that it's there.

Question: what does turning the key on and off do with the injectors (or did you mean to start the car then turn it off again)?

As for the intake manifold, I was thinking COP/boot from the get-go, but a local mechanic I trust quite a bit pointed me toward a vaccuum leak, and that's why I started wondering in that area. And lots of places online have IM gaskets for $20-25, local auto shops would probably have something around $30-35 if they even have it in stock.

Thanks again for the help, I'll post my findings up here.
 
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#10 ·
CapnGnarly said:
+rep for the huge help, man.

I'm 99.99% sure there's not a problem with the plugs. I've seen this issue across two full changes of plugs and never saw corrosion or damage on any of them.
Click to expand...
Nobody ever seems to understand why I say pull the plugs when you have engine running problems. It has nothing to do with the plugs being bad- it's diagnostics. Even if you have a DTC pop up, your spark plugs are a very important diagnostic tool. That's why I wrote, if it runs, put a standard (not rare metal) plug in place of whatever you have in that cylinder so it will build up deposits we can see- if you don't have any deposits on the plugs you have right now. It has nothing to do with the current condition of the plugs- it's diagnostics. Plug deposits will verify what the PCM is telling us, or turn it around in a completely different direction. Don't throw the good plug away, just replace it with something that will build up deposits so we can figure out what's going on in the combustion chamber. Plat and iridium plugs don't build up deposits- so it's difficult to properly diagnose problems with these plugs.

What's probably going on is that you have a bad/stuck injector- that was the other test where you'd cycle the key a couple of times, then pull the plug and smell for fuel or look for fuel on the plug. Comparing the condition of plug #4 to another plug (I used #3 as an example) is also important. If you see a little fuel on #4, then #3 is freaking swimming- you've just verified what's happening. More likely it will be like this- pull out #4, sniff, smell a little fuel, pull out #3, and you get high off it.

It's not like it's hard to pull a plug on these engines. You want hard- get you an Aerostar with a 3.0 or an old GM G-body where you have to gather up things you'd think you'd never use to pull a plug in order to get access- like a wrench to use on the end of the plug tool in the Aerostar because you can't put a plug socket in there with any sort of ratchet on the end of it. And yes, if there was a problem with that engine, I'd have to pull #3 because it seemed like all the problems with that engine were on #3.
 
Discussion starter · #11 ·
whynotthinkwhynot said:
Nobody ever seems to understand why I say pull the plugs when you have engine running problems. It has nothing to do with the plugs being bad- it's diagnostics. Even if you have a DTC pop up, your spark plugs are a very important diagnostic tool. That's why I wrote, if it runs, put a standard (not rare metal) plug in place of whatever you have in that cylinder so it will build up deposits we can see- if you don't have any deposits on the plugs you have right now. It has nothing to do with the current condition of the plugs- it's diagnostics. Plug deposits will verify what the PCM is telling us, or turn it around in a completely different direction. Don't throw the good plug away, just replace it with something that will build up deposits so we can figure out what's going on in the combustion chamber. Plat and iridium plugs don't build up deposits- so it's difficult to properly diagnose problems with these plugs.

What's probably going on is that you have a bad/stuck injector- that was the other test where you'd cycle the key a couple of times, then pull the plug and smell for fuel or look for fuel on the plug. Comparing the condition of plug #4 to another plug (I used #3 as an example) is also important. If you see a little fuel on #4, then #3 is freaking swimming- you've just verified what's happening. More likely it will be like this- pull out #4, sniff, smell a little fuel, pull out #3, and you get high off it.

It's not like it's hard to pull a plug on these engines. You want hard- get you an Aerostar with a 3.0 or an old GM G-body where you have to gather up things you'd think you'd never use to pull a plug in order to get access- like a wrench to use on the end of the plug tool in the Aerostar because you can't put a plug socket in there with any sort of ratchet on the end of it. And yes, if there was a problem with that engine, I'd have to pull #3 because it seemed like all the problems with that engine were on #3.
Click to expand...
I hear you. Makes perfect sense. I won't be able to throw new plugs in for a couple days 'cause I don't get paid for a couple days, but I'll pull what I have and check them tonight (including the "sniff" test) and see if I find anything.
 
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#12 ·
i usually start the car..and one by one pull each spark plug..the car should really rock n shake, if it does then you know the wire/plug is fine..if you pull another plug and no change in engine stumble then chances are the plug/wire is faulty...
 
Discussion starter · #13 ·
Okay.

Sniff test, cyl 4 (the offending cylinder) had a fairly faint smell of gas and was relatively dry. Cyl 3 on the other hand, was wet and definitely had a nice intoxicating odor to it.

The boots (all 4) looked just fine, and i re-greased all of the plugs and boots just to be sure.

The plug in cyl 4 had a very tiny amount of white, dry, powder-ish deposit on the band (not the core, just the outside portion of the band).

It has been clearing itself up lately, however. Weather is the biggest variable, the misfires began on a wet, cold, and snowy night. It is now dry, cold, and mostly salty qbut the roads and parking lots are clear and nothing is falling from the sky like it was. The misfires have gone from non-stop (the cylinder never firing) to sporadic at best (3-5 stumbles per minute, more at idle).

I have also cleaned my air filter of salt and snow and ice that was getting caked on it, and checked the ignition wiring (found nothing, granted i didn't get in there with a multimeter or anything, but they looked and felt fine).

Hope this helps your brain put the pieces together, and thank you a to n for helping me get this far.
 
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#15 ·
From what whynotthinkwhynot stated. You should pull your fuel injector on number 4 and clean it.

You can get a spray injector cleaner that you can spray on the injectors them selves to run it for a little while longer while you save up for some new injectors ... or just get new injectors if you have the funds for it.

-Ray-
 
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#16 ·
Yep, sorry, haven't been on the computer due to my daughter's birthday festival. Whoa, I'm having a party somewhere else next year.

Anyway, you found the problem- bad or stuck injector. If you're not comfortable removing the injector, then you can try those FI injector cleaners. Just let me warn you why I don't recommend this off the top: 1) If something is stuck in there resisting movement of the plunger, then you're not going to force it to go out the way that it's stuck. It's like trying to keep a 500 lb Canary in a cage. 2) Even if it did work to slowly dislodge whatever is stuck in there, it's not going to do it all in a single tank. 3) This won't fix a failing solenoid.

Basically if you put one bottle of FI cleaner in a tank, you're going to be disappointed. It's something that has to be done over a period of time. Some people recommend Seafoam (thanks to CarTalk), other people recommend Techron, a few recommend Lucas, and even fewer recommend Marvel Mystery Oil. No matter which one you feel like is going to be your magic bullet- you should do it for about 5 tanks of fuel before you throw your hands up in disgust, and replace the injector. That's expensive, and if you're using Techron or Seafoam, you could've purchased an injector, and complete O-ring kit (since you have to pull all of them to get one out) with the same money. That's why I recommend the latter two. If you purchase the Lucas FI cleaner/upper cylinder lube in a quart for $8, you have 6 tanks of treatment, and the same goes for MMO but you only spend $6. That way you haven't spent $40 on treatment before you give up and replace the injector. Lots of people think you have to spend a lot to get something- but in the case of FI cleaners that you put in the tank, IMO- spend less because it's more likely that none of them will work at all because none of them will "fix" a mechanical problem.

Yeah, I use Lucas that I purchase by the gallon, but only because it gives the wife's van 3+ mpg, and that's cost effective if I purchase by the gallon. The only drawback is that it's hard to convince her to put it in every tank. In my car I use MMO in the oil and sometimes fuel. I've had a lot of experience with this product in the crankcase with old hydraulic lifter engines- like for junkyard replacement engines. I have a slight rough idle due to one stubborn injector, and it does alleviate (though not completely disappear) when I use MMO. I do not get DTCs, so it's not that big of a deal, but I might fix it because it could be causing me to use too much fuel. Maybe get 2 more mpg, with gas going up to $4/gal permanently- I need that 2 mpg.
 
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whynotthinkwhynot
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