98 Tacoma Cylinder 5 Misfire
01-29-2007, 06:13 PM
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98 Tacoma Cylinder 5 Misfire
Hi everyone! First off I am new to this site, and want to thank anyone who can help me out with my problem. I have a problem with my 98 Tacoma 3.4ltr V6 engine misfiring. Until this weekend, I didnt know which cylinder the problem was on. So, last week I replaced all my plugs and the 3 plug wires. That fixed the problem for about 5 minutes and then it started misfiring again. I have a friend who owns a computer program for his laptop that reads engine codes and he came over this weekend. We got a P0305 Misfire Cylinder 5 code. I have 2 questions. First, which cylinder is #5 when looking at the engine? My guess is the furthest back on the passenger side. Once that is determined, what should my next step be? Should I replace the coil pack? Does to coil pack include the boot that connects it to the plug? Thanks so much for any help you can give me. I am a novice at this, but trying to learn as much as I can about my truck.
01-29-2007, 06:33 PM
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Don't know if this will help, but I had one cylinder in my 3.0l V6 that would crack spark plugs(cyl #3), and would act like it was missing. Turned out the fuel injector was plugged and was just dripping fuel. After the fuel injector service from RC Engineering, everything runs great!
01-29-2007, 08:57 PM
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Hit the SEARCH button and look for "misfire" they've been croping up a lot lately.
https://www.yotatech.com/forums/f2/2003-tacoma-check-engine-light-102454/
https://www.yotatech.com/forums/f2/p0304-code-misfire-cylinder-4-a-102131/
https://www.yotatech.com/forums/f2/p303-misfire-detected-100681/
Injectors, plugs, wires... something that's specific to the one cylinder. As such, it's probably NOT the coil pack since that would cause a misfire on two cylinders - this engine is what's known as "wasted spark" so two cylinders fire at once. One while it's at the top of the compression stroke, the other while it's on the exhaust stroke. This is done to simplify the ignition system.
On the extreme end (and fairly unlikely) it could be something major like a burned valve.
Past what kind of plugs you put in - did you gap them first?
https://www.yotatech.com/forums/f2/2003-tacoma-check-engine-light-102454/
https://www.yotatech.com/forums/f2/p0304-code-misfire-cylinder-4-a-102131/
https://www.yotatech.com/forums/f2/p303-misfire-detected-100681/
Injectors, plugs, wires... something that's specific to the one cylinder. As such, it's probably NOT the coil pack since that would cause a misfire on two cylinders - this engine is what's known as "wasted spark" so two cylinders fire at once. One while it's at the top of the compression stroke, the other while it's on the exhaust stroke. This is done to simplify the ignition system.
On the extreme end (and fairly unlikely) it could be something major like a burned valve.
Past what kind of plugs you put in - did you gap them first?
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01-29-2007, 09:20 PM
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...and you're looking for a resistance of 13-16ohms across the coil. Too much more than that and it won't open all the way (or at all) when it's time, any less and the ECU is working too hard and you'll run the risk of burning it up.
02-03-2007, 06:17 PM
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Still working on the problem
Hey guys! Thanks for the warm welcome and all the suggestions. After taking a suggestion from a mechanic and not chicking back on here first, I replaced the coil pack... as you can guess, that didnt fix the problem. And to top it off I purchased it directly from the Toy dealer in town and paid just under 100 for it. In response to a couple of the posts, I used NGK plugs and i didnt gap them. What is gaping them? My neighbor who seems to be a pretty damn good mechanic actually put the plugs in for me, but he didnt say anything about gaping them. He did tighten them and then backed them off a slight amount if that is what gaping is. I will be checking the resistance across the coil. If the proper resistance is there, does that necessarily mean that it is functioning properly, or could it still be bad. I am really hoping that it is just the injector and not the valve!!!!! THanks so much for your help guys! You are making the process much easier for a novice mechanic! I will certianly be checking this post before I purchase any more parts!!!
02-03-2007, 08:39 PM
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I suggest pulling the intake tube off. The number 5 injector is the one closest to the firewall. Unplug the clip from the injector. Use the ohm meter and check the reading on the injector itself. You should be somewhere between 13-16ohms. Let us know what you get. If you don't get a reading, your injector is dead.
02-03-2007, 08:43 PM
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Prior to pulling the entire intake manifold off and testing the #5 injector, you might want to pull all the plugs and gap them properly with a feeler-type gapper. Make sure the plugs match what's required for the 5VZFE engine as it tends to be quite finicky about plug type.
You can get this type of gapper at any decent auto parts store. Again, it has to be the feeler type and you have to make sure both electrodes are gapped the same on each plug.
You can get this type of gapper at any decent auto parts store. Again, it has to be the feeler type and you have to make sure both electrodes are gapped the same on each plug.
Last edited by rimpainter.com; 02-03-2007 at 08:44 PM.
02-03-2007, 08:45 PM
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Prior to pulling the entire intake manifold off and testing the #5 injector, you might want to pull all the plugs and gap them properly with a feeler-type gapper. Make sure the plugs match what's required for the 5VZFE engine as it tends to be quite finicky about plug type.
You can get this type of gapper at any decent auto parts store. Again, it has to be the feeler type and you have to make sure both electrodes are gapped the same on each plug.
You can get this type of gapper at any decent auto parts store. Again, it has to be the feeler type and you have to make sure both electrodes are gapped the same on each plug.
Actually I'll take some pictures tomorrow. You do not need to take the manifold off to test the #5 injector.
02-04-2007, 07:38 AM
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Thanks guys! Well despite the -13 degree temp here in MN today, I am going to try to get out and check the resistance on the injector. I am also going to look around and see if I can come up with a gapper. However, if I had misgapped them ,wouldnt you expect to see more than one cylindermisfiring? Thanks for all the help!
02-04-2007, 08:47 AM
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Ok, I'll do my best to write this up for you.
First remove the air intake tube
Second locate the #5 fuel injector
Next unplug the the fuel injector clip
Last test the resistance on the fuel injector.
I hope this helps. Good luck.
First remove the air intake tube
Second locate the #5 fuel injector
Next unplug the the fuel injector clip
Last test the resistance on the fuel injector.
I hope this helps. Good luck.
02-05-2007, 07:27 PM
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Fixed~!!!
Hey guys! Well, I tested the resistance across the injector and it was almost zero. I purchased a new one from Auto Zone, and everything seems to be working fine. I test drove it for about 20 miles, and it is running great. Thanks for all your recommendations and help... couldnt have done it with out the help!!
02-06-2007, 05:36 AM
#19
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Cool on finding the injector, but let's finish this side of it as well...
So... you DIDN'T gap them?
You really need to.
The plugs will come out of the box in a variety of gap sizes. Some will be tight, some will be WAY open, they will RARELY be what you need for your engine. Improper gapping will lead to a loss of power.
You really need to.
The plugs will come out of the box in a variety of gap sizes. Some will be tight, some will be WAY open, they will RARELY be what you need for your engine. Improper gapping will lead to a loss of power.
02-06-2007, 06:05 AM
#20
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Hey guys! Well, I tested the resistance across the injector and it was almost zero. I purchased a new one from Auto Zone, and everything seems to be working fine. I test drove it for about 20 miles, and it is running great. Thanks for all your recommendations and help... couldnt have done it with out the help!!
That is exactly how YT should work.
Last edited by MTL_4runner; 02-06-2007 at 06:25 AM.
