1jzgte wont rev past 3.5g??

[japlish]

i was going to just post in rshuwy's thread but mine is slightly different, i've already seached a number of site's/threads and everyone else has ecu problems or coil problems so don't go and tell me to search!

i have a mx83 with a jzx90 1jzgte running an auto ecu with a r154.
it starts and idles PERFECTLY everytime and will rev smoothly in neutral up to about 3.5-4000rpm, after that it just hits a wall of sputtering and popping.
when you drive it its even worse, you can hold your foot flat and it feels no faster than a ke70! it doesn't even make boost!

things i have done:
replaced turbo's
ecu was checked by an auto elec and no codes came up
coils were bench checked by an auto elec and they were fine
spark plugs replaced
the inards of the ecu are fine and there are no leaking capacitors etc....
changed ignitor
vacum lines to fuel reg and map sensor are clean
timing belt is aligned correctly
walbro fuel pump
i think thats about it?

now i know there's always other bits that need checking but it usually comes up through the ecu check light right?
it could be mechanical but what?

[pato]

if it were me, i would be borrowning a known working ecu and trying it in your car.

jsut becasue the ecu doesnt throw any codes, doesnt mean its not fucked.

my blitz access started, idled, cruised etc perfect, but as soon as positive pressure was seen, it would send the injectors to 100% duty.
the ecu never once threw a code, and the board and caps look mint.

as soon as i chucked in a new ecu. went perfect.

1jz ecu's seem to be a tempremental bitch.
ive had 3 break on me now.

[japlish]

hmm, i was guna try changing the ecu and i got another one but its a different version with different plugs....on the hunt for another one at the moment.

[TurboRA28]

Have you put a wideband 02 meter on it to see what the mixtures are doing at that point?

[LeaThaL]

might of been a jzz30 or jzx81 ecu, that happens alot

agreed tho, try another ecu as ive heard the same, one of the fellas on the z20soarer forums had the same issue.

whereabouts are you as i can bring my borrowed one around to test if its nearby

[japlish]

i have a wideband but can't get to it till next week , although after changing the pump the cough got a little louder meaning more fuel coming out/being burnt?

i'm pretty sure mines a jzx90 unit as i have 2 other mates with jzx81 ecu's and they're different.
i'm in toowomba leaThaL

[Radar]

Have you tried tightening up the exhaust manifold and turbo bolts? Vacuum leaks?

[pandaah]

tried cleaning your injectors?.... maybe there slightly blocked and can only flow a certain amount of fuel

[senn]

Make sure your Throttle and kickdown cable aren't round the wrong way?

[sheepers]

have you checked your coil sticky outy things for cracks??

also, how much have you driven the car since its first start up? (i dont even know if you've done an engine conversion and this is your first drive....)
but mine will miss like a bastard if its been sitting in the shed being started and stopped all the time. like when i set up my new radiator and intercooler, i was starting the motor and letting it run for a minute or two, then switching it off, much like youd do in the last stages of an engine conversion checking oil leaks and shit. they run really rich at this time and it tends to flood everything in fuel.
anywho, it will miss real bad until its got a bit of temperature in it and i give a bit of full throttle for a couple of gear changes. it clears up and then is fine unil the next time i have to so something.
oh, and for the record, my ECU is completely fucked (i took it apart about a year ago and the caps were leaking all over the place, ive been meaning to fix it for some time but im lazy and have other cars to work on) and it still goes fine.
anywho, might be that???

sheepers

[japlish]

lots of idea's, i like

vacuum leaks wont stop it from reving and injectors MAY need checking but the wideband will tell me that.

senn: kickdown cable? it's manual??

sheepers: i myself didn't do the conversion but the fellow who did was pretty into his electronics. i have driven it for about 20mins in 1 stretch and it didn't go away whatsoever.

anybody got a jzx90 ecu i can borrow?

[pato]

so when it "coughs" is there crap loads of black smoke pouring out the back ??
i think someone mentioned, blocked fuel filter, clean the injectors,

if theres no black smoke, sounds like its choking from lack of fuel, pity u dont have your wideband now, could find out straight away

[bk_]

Hi japlish,

Was this a problem since the beginning or much later after the conversion?

if it is OK in neutral (up to a point) but not under load at all (do you have a boost gauge?), there may be an air measurement issue.

I know my MAP sensor is off by 5% in terms of reading according to my custom-made OBD reader (eg: it reads 96 MPa instead of 101 MPa when engine is not running). I "resolved" that issue by using a voltage regulator to up the source voltage a tiny bit (by 0.15V if I can remember). I also had an issue with my TPS (JZX81-based) that read slightly differently to a JZZ30-based TPS. Altering both, together with a manual-based chipped ECU resolved most of my issues.

I used to run an auto ecu with manual gearbox and had my fair share of interesting issues, heh.

Just some ideas.

BK.

[pato]

my map sensor reads wrong as well,
reads allmost .1 of a bar lower than iam actually hitting,

[bk_]

I forgot to describe the problem I was having.

Basically up until 2900 revs, it would feel like a slow piece of crap, even though it was boosting to 6-9psi. Then all the power came on suddenly after that. Do you experience this type of behaviour? or does it feel like a slug at any rev, even beyond 3000? I never tested it beyond 4000 rpm before making the changes.

For me, the TPS was the main problem. Altering the MAP sensor and having a manual-based chipped ECU resolved the non-smooth running issue.

Hmm... is your MAT sensor OK? someone on toymods had a physically broken sensor so that could be one possibility, but if the ECU doesn't show any codes... then I don't know.

Are you running the TRC throttle body? is the traction control connected or disabled?

Did you replace your vacuum lines? I remember all the vacuum lines on my engine had breaks and holes in them! Fortunately I inspected and fixed all vacuum lines prior to engine installation.

BK.