1JZ GTE break up issues at higher RPMS

[nodla]

i have a 1jz out of a (JDM) supra and put into my supra. all wired up and running. setup:

delphi fuel pump
FMIC
intake
open downpipe
R154 trans
OS Giken clutch
stock twins (no boost controller)

basically my problems im having is:

1. when i hammer on the throttle it starts breaking up around 4-5k.

2. slight hiccups at idle every once and a while

3. Idle will lope occasionally.

Things I have tried:
-checking ECU wiring.
-sent ECU out to get repaired (blown capacitor -- wouldn't run before)
-replaced and regapped spark plugs

any ideas would be much appreciated!

 

[S.A. supra]

Check the coil packs for cracks. Thats pretty common with the 1jz. I had to buy all new ones. They cost little under $500.

 

[JonoTurbo]

x2 on checking your coilpacks, also, what gap are you running?

Also, you don't have to replace the coilpacks if they are cracked, I used epoxy to seal the cracks on mine 3 years ago and it's been fine.

 

[nodla]

thanks! i gapped to .030. (NGK coppers) i read somewhere thats a good gap for them when u start to run higher boost (which i will be doing when i get this fixed)

 

[suprahero]

Are you running lean in the higher rpms?
If you know it's not because you're running out of fuel, try gapping your plugs to .026 and see how your car likes that. I actually run mine at .020 but I'm run 22psi. Good luck.

 

[nodla]

i dont have a wideband yet.
But i am inclined to believe I am running rich, due to the plugs being black and smelling of fuel.

suprahero, are u running NGK bkr6es?

I will check my coil packs tonight when i get back from class.

 

[Nalleywhacker]

x2 on checking you coils and regap your plugs to 25-27ish

 

[suprahero]

I run the NGK 4644's that replaced the NGK 6097.

 

[Bigzavs]

i dont have a wideband yet.
But i am inclined to believe I am running rich, due to the plugs being black and smelling of fuel.

suprahero, are u running NGK bkr6es?

I will check my coil packs tonight when i get back from class.

if those are the plugs ur running, you need to get rid of them, these motors dont like any plug hotter than a 7 heat range (which is the plug suprahero said hes running)

 

[nodla]

thanks for the input... its freezing raining outside so im gona check the coil packs tomorrow. lol.

Bigzavs -- do you think the 6 heat range could be causing my break up? or is it just over time my engine isn't going to be happy w/ the hotter plugs?

 

[S.A. supra]

I run the NGK 4644's that replaced the NGK 6097.

+1

x2 on checking your coilpacks, also, what gap are you running?

Also, you don't have to replace the coilpacks if they are cracked, I used epoxy to seal the cracks on mine 3 years ago and it's been fine.

I tried that epoxy, but it didn't work all that well. It was still breaking up at high boost. But then again all my coil packs had 6 or 7 cracks on each, from top to bottom. They were in bad shape.

 

[88mkIIIproject]

+1



I tried that epoxy, but it didn't work all that well. It was still breaking up at high boost. But then again all my coil packs had 6 or 7 cracks on each, from top to bottom. They were in bad shape.

I'm having the same problem, tried the epoxy, but still run into it either when the engine is very hot, or very cold...in between it is fine.

the cracks on mine aren't even that bad...I think I priced them from Champion Toyota at like $75/piece for the coils. I need to invest.

 

[nodla]

Pulled my coil packs:

Found a few cracks: (just snapped a pic w/ my cell of 2 of the cracks)

So basically I just take some epoxy and smear a thin coat over the cracks?

 

[S.A. supra]

Your pics aren't working.
epoxy and heat wraps.

 

[NokaoiMK3]

Hmm I seem to be having the same problem around 2k.. Let me know if your coil packs was the culprit..

 

[nodla]

pictures fixed?

edit: also found another crack in the plastic under the rubber boot.

edit 2: make that 3 cracks under 3 of the boots.

 

[scottiedawg66]

yes they are fixed. not sure about the epoxy route on the coil pack, but my car was doing the same thing. gapped to .026 and loving it sorry I forget what speficially what plug I am running, but NGKs are the way to go.

 

[JonoTurbo]

Make sure you pull the blue boots off the bottoms of the coils, it is very common for cracks to form beneath them.

 

[nodla]

yeah i found 3 of them had cracks underneath the boots.

Thanks for everyones help! i hope this fixes it. The expoy is drying now.

 

[johnd]

Also check the coil pack connector clips if there broken they can cause problems also.