So I just finished putting new wires and new plugs (mostly) on my 3.4. I still need to replace the furthest back on the driver side (#6 I guess?) because I didn't have an extension long enough to get it out.

Anyway, the engine was misfiring under heavy load in O/D which is why I had a look at the wires. The spring inside the boots on the first and third wires (driver's side) had broken off onto the spark plug tops so I I figured that was my problem.

After replacing everything, the misfire is way worse now. No MIL is coming on so I don't know if I can even figure out which cylinder is misfiring.

Primary and secondary resistance was good on all the coils except one. Secondary resistance was way high on one of the coils. I pulled off the boot on the coil and cleaned up the connection b/w the boot and the coil really well. Secondary resistance was fine when I tested the coil with the boot off. I just realized I forgot to test the secondary resistance after cleaning the boot and putting it back on.

I also noticed that there was a lot of dialectric grease inside the boots of the coil packs.

So my questions iare...

Is it okay to remove the boots from the coil packs like I did or is that a no-no?
If it is okay, does Toyota sell just the boots for the coil packs? Also, is there a good way to clean excess dialectric grease off the connections inside the coil pack boot?
Should I get 1 (or 3 new coil packs)? Does the ECU store info about misfires even if the MIL does not come on?

Thanks.

 

Well I pulled the boots off the coil packs again. I also figured out that you can pull the connector (little spring and metal contact) out of the boot easily as well.

One of the springs was totally caked in dialectric grease. I hope this is my problem. I tested secondary resistance on all of them again and all seems well. Hopefully it's just all that grease is keeping spring from contacting the spark plug correctly. Supposedly, rubbing alcohol is good for removing dialectric grease. I am going to clean them up really well and replace that last spark plug and see what happens.

 

is it possible to just replace that spring if you cant get it clean? i was told by the dealership you cant just replace the boots, you have to replace the whole coil and the spring usually comes with the boots. im not sure if the springs would be a universal size, but i just replaced the boots on my 2000 cadillac deville and was able to buy the boots with springs for $8 each. maybe take the old spring to the parts store and ask if you can compare it to the spring for the cadillac? just a thought if you cant get the spring cleaned enough.

 

I chased a similar problem on my 97 limited.Turned out to be the injectors.Break out a engine-o-scope or something you can listen to each injector individually.I did this after a full set of coilpacks from the dealer(which wasnt cheap as you can guess),plugs,wires and alot of swearing that I would burn it to the dirt if it didnt work.Turned out after injectors it ran like new.(Go figure) I got a rebuilt set of OEM toyotas from http://www.fiveomotorsport.com/ I use them in my mustang and figured why not.Great company to deal with and awsome prices with a core refund.Hope this helps.

 

Thanks. It looks like I can clean the springs sufficiently and I won't need to replace them. Just waiting for the wife to get home from work so I can run out and get an extension for the one spark plug and I'll see how she runs after that.

 

That's a good idea. I did have my injectors professionally cleaned a couple of years ago and the guy who cleaned them said they were in good working order at that time. But, it probably wouldn't hurt to listen to them with a stethascope. I'll probably pick one up while I am out just to rule that possibility out.

 

It is possible to use too much dielectic grease to where it acts as a preventative to making good contact.

Get a toothpick, squeeze out some dielectric grease, and then just pick up a small amount on the toothpick and put it inside the boot (about the size of a drop of water).

If your injectors were good to go beforehand, just run some BG 44k in the fuel tank before your next oil change. If you have never changed the fuel filter, do so afterwards.

I have a hankerin for some hamburger steak at the Thicket now. Oh well, not in Columbia today.

 

Haha. The cafeteria at my job served hamburger steak last week. It left me unsatisfied I must say!

Anyway, yeah I figured I put too much grease on at some point in the past. I didn't realize that stuff was not conductive until just recently.

But good news, after cleaning everything up and replacing that last spark plug, everything seems to be good now. I went for a drive and it misfired at the very beginning while in O/D on North Trenholm but after a few minutes it completely went away. The motor definitely seems smoother in general and has a tiny bit more umph on the low end. I hope this one is solved.
Thanks for all of the replies.

 

If it happens again an easy way to help narrow things down is to switch the coils from 1 bank to another and see if the problem follows it. If it does then you know it is the coil, if not then it is something else.