cylinder 3 misfire

[saverio7]

Hi all. I'm new to the forum here, but this looks like the place to be to get some help.

I have a 2000 camry 4 cyl that the engine light came on recently, then started blinking randomly. It has 160k miles on it and gets serviced regularly. Changed the computer about a year and a half ago because it was giving a faulty EGR valve code and couldn't pass emissions, but got the EGR replaced anyway in the process. Other than that, has run very well and no problems.

Yesterday coming home from work, engine light came on and engine started running poorly at idle, and then would hesitate when accelerating. It would then smooth out while going anywhere over 30 mph. I got about a mile and the light started blinking and I pulled it into a garage real quick and pulled a 'cylinder 3 misfire' code. Changed the plugs and third plug was dark with a small amount of oil on it and didn't look like it had been firing at all. After changing plugs, engine was still the same. At this point, I checked to see if it was the wires or coil and both were functioning properly. So now I'm just trying to see if anyone has any ideas on where to look next. My thoughts were the fuel injector and/or to get the compression checked, but I'm not a very experienced mechanic and was seeing if there was something I'm not seeing or overlooking. It definitely seems isolated to that one cylinder, that's why I'm thinking injector or rings or something.

Hope that's enough information. Thanks in advance for any help.

[abew330]

try swapping coil packs to see if code jumps.

this isnt the best way to test it but you can also try disconnecting injector#3 while engine running to see if idle changes or not (if change=injector should be fine.. no change=injector bad)

might not help but i would clean connections to coil packs / injectors

[saverio7]

Ok, I"ll give this a shot in the morning and give and update then. Just to make sure I have this right:

I'm going to recheck and clean all the connections, swap the coils to see if code moves, and then check the injector by disconnecting it while the engine is running. On that last one, if I disconnect an injector, won't the engine idle rough the same way because of the lose of that cylinder, hence no change?

Thanks for your reply.

[Mike Gerber]

Check that third plug wire for continuity with a digital volt/ohmeter. That wire may have an internal break in it that could be causing your misfire.

Mike

[saverio7]

Wires all looked good as well as connections. Disconnected the 3rd injector and engine ran the same, so I'm assuming that the injector may be the problem from what was said a couple of posts ago. Unless someone has any other thoughts, I'll try to change the injector out and see what happens. Thanks and I'll update in a bit.

[Mike Gerber]

You could try switching that injector with another cylinder and see if the miss moves to that other cylinder or remains with cylinder number 3. This would varify if it's a problem with that injector, or an ignition system problem and possibly save you the cost of an injector.

"Wires all looked good as well as connections."

Wires can look good and still have an internal break.

Mike

[93celicaconv]

Mike Gerber is spot on with his advice. I've had many plug wires arc inside the spark plug tubes. And it is almost impossible to tell from a visual on the spark plug wire whether it is arcing or not. When a plug wire arcs inside the spark plug tube, the plug will not spark.

You can disconnect the injector on cylinder #3, but all that on its own will tell you is if cylinder #3 is not firing (if no change after removing the wiring harness, then cylinder #3 is not firing when the injector is connected also).

I would add to the instruction to actually slowly remove the #3 spark plug wire while the engine is running (being very careful, of course). Once separated from the spark plug, slowly raise it. Is the wire arcing to the spark plug tube from the very bottom (which is OK), not arcing at all (open wire or broken coil pack), or is it arcing somewhere along the side of the spark plug wire tube to the spark plug tube (defective spark plug wire).

If the spark plug wire only arcs from the bottom to the spark plug tube, I would concentrate on the injector.

[redekud]

Sorry for barging in, but I'm having an identical problem with the 4th cyl of a 2000 4 cyl Camry with 193K miles. I replaced the valve cover gasket and tube seals at the top. All injectors are "clicking" and have new plugs and wires. Compression is good. I too have a little oil residue around only the 4th plug. The oil is on the outside where the sparkplug wire connects. Another interesting tidbit: the 4th cyl spark plug wire keeps "moving up" off the valve cover as if being pushed up by pressure. I've read elsewhere about "unscrewing" the spark plug tube, cleaning the threads, applying black rtv to the threads and screwing back in. Do the tubes really unscrew?

[redekud]

Found this on another post:

"I had the exact same problem, oil leaking into one of the spark plug tubes. Camry service manual says to use three bond 1324 thread sealant or equivalent. Good luck

To remove the spark plug tubes, try this http://wiki.answers.com/Q/What_would...o_do_to_fix_it . I ended up using a channellock plier to remove it."

I'm gonna try resealing the tube tomorrow. BTW, tube torque is 36 ft lbs per yet another post.

[Mike Gerber]

"BTW, tube torque is 36 ft lbs per yet another post."

I think the correct torque is 29 ft lbs. At least that's what it is on the 94 Camry 5SFE engine. I would check a manual to be certain. Remember, that's for reseating the tubes in to the cylinder head, without the valve cover on. If you use that amount of torque on the valve cover you will crack it. The correct valve cover torque is only 17 ft lbs. If you don't have a manual you can download a Toyota factory service manual for free at the top of the Camry forum over at AutomotiveForums.com.

Mike

[93celicaconv]

Redekud, when you said you are having the same problem with cylinder #4, is that problem a constant misfire until your reach higher engine RPM's?

The presence of oil in the #4 spark plug tube should be corrected. But in and of itself, oil in the tube does not automatically mean that cylinder will always misfire. If you replaced the spark plug and wire on #4 cylinder, the problem should have gone away, even if oil is gradually seeping it's way in there. Regarding the spark plug wire lifting up, is the plug connector "snapping" and "locking" onto the sparkplug properly? Or can't you hear a snap or feel a lock when you push it down over the spark plug? It should do this. If not, the connector on the wire is defective and the wire should be replaced. Otherwise, oil weeping into the spark plug tube from the bottom would not pressurize the spark plug tube to life the wire up. But, a grommet on this tube from the valve cover, if not properly installed and if leaking badly, could. Maybe that is the source of your oil leak too? If you really are getting pressure in the #4 spark plug tube, the only place it can get that pressure is from a leaking valve cover grommet defect to your spark plug tube.

You can take a look at post 7 in this thread and try that to see if you find that maybe your plug wire is arcing to the spark plug tube from the side (not good) rather than from the bottom (good) or not at all (not good) as you lift it. This might tell you a lot.

[duke_togo]

Last week, I pulled a cyl4 misfire code from a V6. Experienced the rough idling and inconsistent power too before the CEL came on. Replaced the spark plugs first because they were already close to 60K. cyl4 code came back. Replaced plug wires next. Everything running fine now.

Checked both new wires and old wires on a multimeter. The wire for cyl3-4 would jump between infinity and within spec, so that was probably the culprit.

P.S. Camry runs like a beast again. :-)
P.P.S. Spoke too soon. cyl4 misfire CEL came back after about four weeks. Did a ignition coil swap to see if it was the culprit. Code stayed. Took out the injectors on the front rail, cleaned them up with TB cleaner, and put everything back together. Camry runs like a beast again. Fingers crossed.

[redekud]

Mike Gerber: Would you be so kind as to provide the link on AutomotiveForums.com where the Toyota manual download is? I'm having trouble finding it. My Haynes 97-01 Camry manual says tube nut torque is 33 ft lb, but I'm pretty sure that means with valve cover on.

93celicaconv: I'm getting random cyl misfire that will come and go at all speeds, but most noticeable when accelerating. Sometimes CEL will blink and sometimes not. There is a tight fitting boot at the bottom of the spark plug wire. The pressure pushing the sparkplug wire has to be coming from below the boot. The tube seal is at the top (and new, along with the wire and plug). I did not experience the "pushed up" wire problem with the old wires, but I figured, being 10 yrs old, they just did fit as tight. I have not tried anything yet cause of rain all weekend.

[redekud]

Mike Gerber: Never mind. I re-read your post and found the manuals. Thanks.

[redekud]

The 97-01 Toyota Camry manual specifies 36 ft lb for tubes, and 33 ft lb for valve cover.