1.5JZ not running right

[japlish]

Hi all,

I've had the conversion in the car for two years, running this setup:

jzx90 1jz
R154
emanage blue (zero'd out for now)
440cc injectors
GT35r
walbro
etc.......

this setup has run perfectly and i've never had a problem with it.

Now, i have recently put a 1.5JZ in with bigger 650cc injectors and i've had the head cleaned up and battery in the boot, I haven't changed anything else, not even the emanage!

After getting it all back together finally i got it started and it runs fine for the first 10 seconds? and after that it slowly starts missing to the point where i have to hold the throttle open a tad just so it will idle! I didn't even bother trying to drive it.

I've checked what codes the ecu was throwing and the only code it does is the oxy sensor which was always there as I don't have it in the exhaust, it just hangs down next to the block (IT'S ALWAYS BEEN LIKE THAT)

So just to recap what i have done/checked:

pulled codes
no leaking capacitors in ecu
IAC valve is working/not blocked
spark plugs are fine
repaired cracked coil's (weren't that bad anyway)
timing is spot on (hard to get wrong on a 1jz)
no blown fuses
coil plugs are okish (never been a problem before?)



What the hell is going on???!!!...........

[midnight_purple_GA70]

your injectors are too big for the factory ecu...

you need to get it tuned

it will be dumping in too much fuel at idle/low rpm

put the old 440cc injectors back in and you will probably find it will idle and become somewhat drivable

[japlish]

pity i don't have the other one's around anymore.............i have set the emanage for 650cc injectors, i know they're too big percentage wise for the emanage to cope with properly but i wouldn't think it would make that much of a difference?.........

[midnight_purple_GA70]

try pulling out some fuel from it in the idle/low rpm vacuum areas of the map and see if it helps...

i would have thought the emanage would allow you to use 650s..

i suspect there would be more to it than just telling it they are 650cc injectors...
i dont know much about emanages though

[japlish]

i should have said before that it's not just at idle it's the whole rev range that it splutters (well up to around 3000rpm)

emb are able to handle stock injectors plus another 50%

[midnight_purple_GA70]

yeah if thats all EMB can handle you might be pushing shit up hill...

and yeah if the ecu cant control them properly then the whole rev range will fail

[japlish]

I had thought that before i even bought the injectors but i've seen other's will similar setup's and they've had no problems? maybe running a little rich but that's all.

[midnight_purple_GA70]

well if others have been able to get it working with that combo then its possible... is the impedence right for your 650s/ is it the same as theirs (not sure if the emb cares or not)

i would be trying to remove fuel out of it at idle to at least start attempting to get it to idle properly

possibly remove some fuel from the cold start area of the maps also

[japlish]

yeah i checked them againt the other injectors i use to have and they were the same resistance, the only problem with removing fuel from the maps on emb's is it stuff's the timing around too (that's one thing i don't want to screw with too much myself)

I just don't want a massive bill from the tuner to fix this problem before he even get's to tune it..............

[1jz68u]

if everything in the emanage is zero'd anyway removing fuel will make no difference to the timing. Just pull fuel till it idles. You can not hurt your motor doing this at idle, if you pull to much fuel it will just stall.

But it will not affect your timing.


Source: i have an emanage blue also.

[japlish]

hmm....ok i'll try that and see what happen's, maybe i shouldn't have removed my innovate wideband from the car

[japlish]

well that didn't work so any other idea's? lol..........

[pandaah]

have you checked the fuel pressure at idle? i always recommend putting emanages in the bin and getting a real ecu.. but sounds like you need to check your fuel pressure, then take it for a proper tune

[japlish]

fuel pressure should be the same it has alway's been as i don't have an adj reg. I also just heard back from the injector cleaners and my injectors were perfect so scratch that off the list............

[midnight_purple_GA70]

dont assume...

check pressure at rail...

i assumed that due to my car starting and idling fine fuel pressure was fine (also stock reg)

i had 10psi at idle

culprit was poor installation of a fuel pump had snapped the top off of it and it was shooting some fuel down the line and the rest back into the tank