JZZ30 Soarer misfiring?

[drift-monkey]

Been running fine all day up until a few hours ago where it'll start missing firing under boost at mainly around 3500rpm. Stock standard 1JZ-GTE with end mufflers removed temporarily. So it can't be hitting boost/fuel cut. New spark plugs recently. Could it have been the $20 95 I put in it today? I only ever use 98 but couldn't find a bp near and had to get 95.

Here is a video of it happening.

http://www.youtube.com/watch?v=jqzTs7Hj3Ew&feature=youtu.be

[Shrike]

Could Be your coil packs (what are the spark plugs gapped at?)

[Mr Ree]

Firstly, check the ignition wiring loom, as the connectors get extremely old and brittle under there.

Secondly, remove all the coil packs, and carefully inspect the stems for hairline cracks, and the boots for tears, or excessive oil/grease, and clean as necessary. You can also get some large dia heatshrink, and put it over the stems to avoid tracking, but this is a short term cure to the problem...new coils would be better.

Also, get a multimeter and check that each coil is within spec set out in the TSRM

Finally, how old is your fuel filter?

[drift-monkey]

Was replaced not too long ago according to seller. I would also like to check the coils, if someone didn't strip all the f***** screws on them. All the connectors look fine - however they are brittle. Making creaking noises. Ain't fun. hah. Gonna reset ecu and hope it was bad fuel or something. Checked all vaccuum hoses and intercooler piping etc for leaks, doesn't look like anything is to be found. Plugs / coils it is then.

As for spark plugs - they were done by last owner. So could be 1 - 0.8 - 0.7 . Who knows. Hopefully 0.7.

[drift-monkey]

Upon pulling the plugs out and cleaning, I found that a couple of the bolts that hold the coils in had been stripped and 4 out of 6 were there. MAY have been a contributor.. however. I found a connector that I seem to have missed that looks like...

[drift-monkey]

Wrapped up connector in insulation tape to prevent any kind of possible leaking spark..? Still happening. Will get some new plugs and see what happens

[drift-monkey]

[drift-monkey]

Ended up being that crack, super glue + 2mins then some insulation tape = boostage again! Ordered more spark plugs for nothing..

[Stott69]

is that the case or cover?

[drift-monkey]

I think that parts referred to as the "stem".

[Mr Ree]

Yes, the stem is a very common failure point.

Glad to hear you found the culprit

[Lloyd]

I'd be getting a new coil/boot for it anyway. Patch jobs seems to be a short term fix, and sparks are very good at finding their way out.

[drift-monkey]

Yeah definitely, if it was able to crack in the first place, I don't really think some tape and glue will fix it. New coils are on the cards when money tells me I'm allowed.

Least I know where the problem lies now

[drift-monkey]

Haha, that didn't last long did it.. started happening again, was greeted by 4 cracked coils. cute. Sitting here testing what would be the best way to stop them from leaking spark until i can get some new/working ones.

[Mr Ree]

big tubes of heatshrink, mate

[drift-monkey]

big tubes of heatshrink, mate

Interesting. I will try source some and then will see how it goes. Currently trying epoxy I actually think heatshrink is a good idea, if any new cracks form, no problem. But epoxy is area specific which will allow more cracks.

[phoenix]

I think the heat and vibration would have made quick work of super glue and insulation tape.

On my JZZ30 I had misfiring at 18psi on 20 year old cracked factory coils. I used Selleys Super Strength Araldite as it was rated to 100+ degrees c - the normal stuff will possibly run at temperatures you'll find under the bonnet. Make sure you pull the rubber boots off and seal the cracks all the way too (and put the boots back on afterwards), and check for cracks around the top of the packs. I had zero problems after that.

I didn't use heat shrink over the araldite, but it certainly won't hurt, and should contain the epoxy if it melts. I'd go for this if it fits:
http://www.jaycar.co.nz/productView.asp?ID=WH5646&form=CAT2&SUBCATID=996#1

I'd only go for new coil packs if you going for high boost/500hp+/HKS twin power etc.

[Stott69]

New coils are still around $200 each. the sper spark out of oz are around $600 for the set. As above, Epoxy and heat shirnk has been known to be alright in the short term, but not a performance fix.

[cat007]

+1 for big heat shrink. Or at least multiple sizes of it. 5 layers of heat shrink will be sure to stop any arching

[whynot]

I would be looking for the glue lined heat shrink. The dual wall stuff Is heavier but I think it would be up to the task as we use similar stuff on cable joins then bury it in the ground