Vibration when driving....misfire?

[limitedvan8]

Ok so driving home from skiing a couple weeks ago, truck was driving fine....then all of a sudden i was getting crazy vibrations under partial throttle. coasting or heavy throttle and it was ok. going slow (less than 60 km/h) seemed ok

i thought it might be the rear u-joint, took it to a shop and they tested it out yesterday and say everything looks ok. asked about when i got tires (november) and thought it might be an unbalanced wheel (i doubt this) drove the truck the other day without a hint of vibration

drive the truck to work today and the vibration started again....check engine light on and rough idle

to add, i've had a misfire issue already. when the truck is driven from cold it's fine. park it and let it sit for 30 mins or so then drive it again and the mis fire starts.

so i'm thinking the vibration is actually just the misfire getting worse


when i first bought the truck i had a misfire in cyl 2...new plugs and wires and that went away. i moved the coils around at the time to see if it moved with it...it did but i think the wires were original so that solved it at that time

now i have a misfire in a different cyl (can't remember what my last scan showed, i'll have to do it tonight). i will still need to swap coils around to see if it moves with the coil or if it might be the injector in that cyl...any signs to look out for to see if it's the coil or injector?

 

[jgue467]

I'd inspect the 6 plugs first. Has the intake been cleaned recently? Run any startron, seafoam or other favorite intake cleaner thru it recently? :cowboy:

 

[limitedvan8]

the plugs are new (less than 5 months ago)


I might need to regap them...i thought they came pregapped but when i put my gauge to them they seemed way off....don't really have a lot of experience with gapping plugs

and no other cleaners or anything used

 

[alumarine]

If you used the proper dual electrode plugs they are a bit different to measure and they don't usually if ever need adjustment out of the box.

 

[jgue467]

the plugs are new (less than 5 months ago)


I might need to regap them...i thought they came pregapped but when i put my gauge to them they seemed way off....don't really have a lot of experience with gapping plugs

and no other cleaners or anything used

I was thinking more of pulling them to see their condition not so much the gapping aspect. Any cel codes, check for pending codes too. :cowboy:

 

[limitedvan8]

i'll scan the truck tonight to see if it's still the same cyl misfire

 

[Renegade_Medic]

Just helped a friend in his tacoma with the same problem. It would idle rough and vibrate like crazy under throttle. CEL was flashing. We checked everything and it was a loose spark plug wire. It wasn't snapped all the way down on the plug. Would be an easy thing to check first. You can also try switching coils around to see if throws the same cylinder miss code, after checking codes.

 

[Buckaroo]

any signs to look out for to see if it's the coil or injector?

After you first identify the cylinder via DTC, agree that the next step is to swap spark plugs to see if the problem follows it and then, in a third step, swap ignition coils. That is easy and quick. If that doesn't do it, you can test the injector for resistance - it may take some work to access it depending upon location so recommend that as a fourth step. Finally, if necessary, you can swap injectors to verify the problem.

to add, i've had a misfire issue already. when the truck is driven from cold it's fine. park it and let it sit for 30 mins or so then drive it again and the mis fire starts.

This was exactly the symptom I had when my injector was going bad. The engine would run fine for 20 minutes, then I would shut it down and start it again 5 minutes later and have the misfire. This is typical of a coil going bad - either an ignition coil or the coil in an individual injector. When I tested resistance of the injector coil cold, it tested good but I swapped it and the misfire followed the injector. I finally found out that, when hot, the injector coil tested open which was my problem (hence the issue appearing after engine shutdown & restart when the temperature has had time to ramp up in the injector).

Buckaroo

 

[darrinholst]

Had those symptoms on my Tacoma and it ended up being a plug wire grounding out.


Sent from my iPhone using Tapatalk Pro

 

[limitedvan8]

so i bought a new denso coil and installed it then i had to go away...my wife drove the truck the next day and said the problem was still there just not as bad. i did drive the truck that night for a quick drive after swapping it over and it actually drove much smoother...i'll be replacing the other two coils just for a maintenance


so i'm going to drive it over the next couple of days and see what happens

seems odd that even with new plugs, wires and now a new coil the issue is still there

could the plug have gone bad?

my plan is to pull the injectors and have them all cleaned. this costs about $30/per (joy of living in vancouver) so i'll see how they all check out before buying new....what brand is a good replacement? i'd most likely buy off rockauto or amazon

i can get new OEM ones through a buddy for $130 each so don't really want to buy 6 new ones.

 

[Buckaroo]

Seems like you are just throwing expensive parts at the problem which is fine if you have the money.....I don't.....I would spend time/effort to diagnose and verify the problem before going further.

Buckaroo

 

[Renegade_Medic]

Someone on here was recently talking about baking their injectors and testing the impedance at higher temps and found bad injectors this way. Could be whats going on. Problem is, injectors are a pain to get to.

 

[limitedvan8]

Seems like you are just throwing expensive parts at the problem which is fine if you have the money.....I don't.....I would spend time/effort to diagnose and verify the problem before going further.

Buckaroo

not exactly sure what parts you think i'm throwing at it so far

the plugs and wires were done months ago because they hadn't been done, the wires were rigid and brittle

the coil was $85...two more just for a maintenance peace of mind still isn't that much, and i'll only do it once i know for sure what the end problem is

getting the injectors cleaned i feel is far cheaper than buying all new, unless i can get new ones for a good deal

my next step is testing them....so unless you actually have some more advice one HOW to test and diagnose, your posts are useless

 

[Buckaroo]

After you first identify the cylinder via DTC, agree that the next step is to swap spark plugs to see if the problem follows it and then, in a third step, swap ignition coils. That is easy and quick. If that doesn't do it, you can test the injector for resistance - it may take some work to access it depending upon location so recommend that as a fourth step. Finally, if necessary, you can swap injectors to verify the problem.



This was exactly the symptom I had when my injector was going bad. The engine would run fine for 20 minutes, then I would shut it down and start it again 5 minutes later and have the misfire. This is typical of a coil going bad - either an ignition coil or the coil in an individual injector. When I tested resistance of the injector coil cold, it tested good but I swapped it and the misfire followed the injector. I finally found out that, when hot, the injector coil tested open which was my problem (hence the issue appearing after engine shutdown & restart when the temperature has had time to ramp up in the injector).

OP - These are specific suggestions I made in past post in this thread...have you followed up on them? It appears that you are just flaying about. Take a look at following post...JoshKY used his head, did some great diagnosis and verified his problem....

http://www.toyota-4runner.org/3rd-gen-t4rs/234290-maddening-misfire-mystery.html#post2659446

Also, coils are not really "maintenance" items...I have the originals in my 2000 T4R w/ 240,000 miles.

Cleaning injectors is not a bad idea...I recently did the same - sent them to Witchunter to be cleaned & rebuilt. But it may not fix your problem....

Buckaroo

 

[limitedvan8]

yes i had already verified the cylinder and coil causing the issue, that's why i went ahead and bought the new one, i wasn't concerned with the cost, just like i'm not concerned with buying two more

you may not think they need to be replaced and your truck still runs on the new ones, but it's an electronic devise, it may not fail completely but with time it's efficiency will diminish. and as far as what i've read in the past, the toyota coils don't have the greatest reputation

my next step is to test the injectors

 

[limitedvan8]

so looking at the process of getting at the injectors, how do you test the impedance without removing the upper manifold? or does that in fact need to happen?

 

[limitedvan8]

also drove the car last night for a bit and took it into work today....misfire is still there but the shaking isn't AS bad as before but it's definitely still there.

 

[Buckaroo]

so looking at the process of getting at the injectors, how do you test the impedance without removing the upper manifold? or does that in fact need to happen?

I took the upper and lower plenums off to get to my injectors - not difficult but a little time consuming. It may be possible to get to the electrical connections on the right (passengers side - cylinders 1,3 & 5) without taking off the plenum - not sure. You definitely need to remove the plenum to get to the ones on the left (drivers side - cylinder 2,4 & 6).

Thinking about it, perhaps possible to check them using the pin out on the ECM but would have to understand that it would include the resistance associated with wires/ground...

You are headed down the right road.....Good Luck.....

Buckaroo

 

[limitedvan8]

i'm just buying a new injector....was going to do all 6 but just gonna do the one for now

what seal do i need, the "upper" seal? seems like theres a few if youre looking at rock auto unter injector seals or if i call the dealership