1JZGTE issue

[fatboy13]

Hey,

My 1J seems to be having issues with missing just before it comes on boost. When its cold its almost impossible to drive it misses that badly... its fine once it warms up. But still tends to have a spot just before coming on boost where it leans right out...

Ive checked plugs, coils, ignitor, and map and nothing changes.

Ive got a Haltech interceptor running a base map but ive swapped with a mate and no change either...

any help?

[Dale]

Are your coilpacks cracked?

[BeRad]

When did the missing start? did you change anything on the car?

Dale, my issue with cracked coil packs was, when the car warmed up it missed, due to the fact the plastic gets hot and spreads apart, but cars are wonderful things and its different with every car haha,

Have you got a wideband sensor to tell you its leaning out?

What did the plugs look like when you pulled them, maybe its the opposite and its running massively rich and is fouling the plugs and when you bring it onto boost it burns the carbon off?

So you swapped the interceptor for a stock ecu and no prevail?...

Plug a laptop into the ecu and it might give you a better idea.

[Dieseltrain]

My coilpacks would just sound like my 1JZ was running on 4-5 cylinders.. Not good..

Did you check under the boost on the coil packs and all around the Body?

Mine were cracked everywhere! ALl good now with new ones though

[fatboy13]

Started as soon as i put the 1J in....

So i changed everything...

Im running a pencil turbo timer... which hooks into the ecu and just relays whats its told... it may not be accurate but if it goes off the lean side i can assume its leans seeing as when its boosting the AFRs drop down to good levels so it seems fine.

Plugs looked like they were pretty much fine... nothing showing major rich or lean issues...

and the interceptor is a piggy back that hooks into the existing ecu... i swapped with a mate who has another one on his 1j... when the laptop is plugged in everything shows up fine as its running a base map at the moment

Also ive swapped between a total of 18 different coilpacks with no change...

[lojik]

I have the same issue currently.
It misfires horribly when cold, but is more or less fine once it gets to running temp.

I believe it to be a combination of the cold start enrichment and poor ignition (broken coil pack connectors, old spark plugs)

Could moisture be getting in, and causing electrical problems until it gets boiled away?

[Dieseltrain]

Ok, Have you tried running the Stock ECU by itself to make sure the Haltech isnt the issue?

Seeing as you said its only been doing it since you installed that

[fatboy13]

it was doing it before the haltech as well... its been doing it since the engine conversion.

and if i unplug the haltech ill lose the ability to even start the car... so apart from pulling it back out of the loom..

[unclewal]

it sounds to me like a timing issue, as when its cold it would retard the timing if i am not correct and if its already out a few degrees then it would make it really rough and hard to drive, check the timing on it. Put it on TDC and check the cam gears line up correctly i suspect they are out. Just my thoughts though, i may be wrong, but worth a look if you have checked everything else.

[fatboy13]

we changed the timing belt anyway and checked about a million times to make sure it all lined up... guess it doesnt hurt to check it out again...

thanks guys

[BigWorm]

Mine does a very similar thing when cold, a slight miss/hesitation when cold just before coming on to boost. It doesn't really bother me as I usually baby it around until it's at operating temp, at which time the miss is gone.
I just did a quick service this arvo, new plugs oil & filters, plus while the coils were out I used that liquid electrical tape on them to fix the cracks in the coils (even though they wern't causing any noticable miss), and I just noticed it had the same hesitation when cold. That's with all standard management, plus a home made FCD.

[big wad]

mine does something similar but more when you lean on it in the upper gears .the local dealer is getting me new coil connector plugs . when i pulled them off and had a good look they were totally rooted but the coils are fine, so hopefully its a $60 fix. cheers big wad

[fatboy13]

thanks heaps guys ill keep looking at things... and hopefully tuning the haltech will kill the issues cos i can stop it leaning out then atleast...

+ rep

[Danners]

Cleaned ISCV yet?

[fatboy13]

no good point...