1J Gurus - spark plug advice

[forey]

1jz standard injectors (60psi fuel pressure) was running fine

Started getting bad idle so i replaced my iridium's with brk6e(standard gap they come with)

it seemed to fix the problem, now while i was changing i/c pipes and what not and starting it without the air sensor thing connected im pretty sure it has fouled and now it idles high and hunts up and down? would this be the case ( runs really well on boost and what not )

heaps more black shit flys out the exhaust more than normal

if so for now, what type of plug should i get? (injectors and re tune in the future)

thanks

[Dieseltrain]

Idle issue wouldnt be plugs to me, coil packs sounds more like it... Plugs will normally be fine, and then play up under boost. Coil packs will play up from idle and anywhere.

Try some BCP7re-11 gapped down to 0.7mm and see how they go. Ive seen a few motors running these plugs produce some decent numbers.

However, i reckon the Iridiums had more off boost throttle response and better off boost acceleration.

[forey]

thing is i dont know how it can go from idling/running fine to idling up and down without it moving from the driveway, the only thing i had done was start it without i/c pipes ( did have one of the threaded sensors in the pipe disconnected )

as in my other thread, it idles pretty high(smooth) but once you hit the brakes or the turbo timer kicks in then it starts to hunt up and down

the only other thing i can think of is that when i was wiring the park lights in that i short circuited it on the body by accident affecting a fuse or something?

sorry guys im still learning! much appreciated

[1JZ~lux]

Are you running the standard ECU? Someone will correct me if I'm wrong but it could be leaking caps in the ECU.

Mine did a similar thing and it was the TPS not adjusted properly so maybe it was bumped when you were cleaning your pipes.

Just a couple more things you could try.

[RollaBabe]

Just learnt a lesson on spark plugs.

I'm chasing a miss in my 1J that only happens in the top end. Was happening at around 8psi before O2 sensor was wired and then once it was wired the miss started at around 10 or 11 psi.
Drove straight home and chucked in a set of Bosch Platinums. Now car won't make over 5 psi. Only bought the bosch cause they we very cheap for platinums.
After reading this tonight (a thread I looked for before i bought plugs and couldn't find) I'll grab some BKR6E's tommorow and see if that solves the problem. Don't touch bosch platinums is the moral of the story. They have a super fine and highly insulated electrode and I think this the causing more dramas then it's helping.Havce always used NGK's or Denso's before now and I won't be swayed again.

A note for you guys running >20Psi and happy gas.

NGK race series plugs equivalent to BCPR/BKR plugs are:

R5672a-8 (-9 or -10) depending on how cold you want

R5671a-8 (-9 or -10) if you want a non projected tip for use with nitrous ect

[Dieseltrain]

Rollababe, Try running some BKR6E plugs . They should come with a 0.8mm gap. See how they go.

Someone once told me Copper plugs are more likely to clean up after running at stoich mixtures for a short period of time ? Any truth to this ?

[RollaBabe]

More likely than that happening with a platinum or iridiums. As far as I know once iridiums foul they are near impossible to revive.

[Dieseltrain]

Yeah, I always used Iridiums . 7 heat range gapped down to 0.7mm . Ran awsome, but one they die, they are fooked !

I did notice however, using octane booster all the time seemed to shorten their life span somewhat !

[RollaBabe]

I put in some BKR6E plugs this morning and its back to backfiing at around 12psi. Its like it overfuels and pops out the exhaust. So over this car. Shoulda done an aftemarket ECU from the get go. Would have been so much simpler.

[Dieseltrain]

What condition are the Coil packs in? Are they cracked ? remove the blue rubber boots and look for cracks down there, Also they crack where the mounting bolts for each coil pack as well...

I dont see how an aftermarket ecu would fix a missfire issue? UNless your Ecu has leaking CAPS in it ?

[RollaBabe]

What condition are the Coil packs in? Are they cracked ? remove the blue rubber boots and look for cracks down there, Also they crack where the mounting bolts for each coil pack as well...

I dont see how an aftermarket ecu would fix a missfire issue? UNless your Ecu has leaking CAPS in it ?

I'll pull all the coils off and have a squizz at em this arvo.

If I had an aftermarket ecu I'd be running Bosch coils on waste spark. Hence no issue. This car has been a pain to wire from the get go.Thats all.

[Dieseltrain]

Yeah, but brand new coil packs, not 18 year old ones, Would fix a missfire as well !

[jak]

we use ngk copper BCPR7ES11's or BKR7ES11's gapped to .6mm for normal use which is 19-22psi on the street. and .4mm gap for nos and race fuel use with 25-30 psi.

Cheers
Jak

[131OWN]

I'm running BKR7E11 with std gap (1.1mm) with my t04z, 24psi, PULP, 1.5j, it revs clean, I must say the Bosch coils are crackers!!!

[RollaBabe]

Yeah, but brand new coil packs, not 18 year old ones, Would fix a missfire as well !

LOL brand new genuine toyota coilpacks are worth more than what i paid for the car. Won't be going down that road.