sc400 Rev cut a 3750 RPM HELP URGENT

[bansheebuzz]

I cant see it being anything to do with speed sensor. When i did my 1uz conversion, i initially had no speed sensor connected(manual trans). It still reved out fine but check light loged a code.

I just finish fixing a customers hilux with 1uz. It had a problem with it shutting the injectors down when switching from rev or drive, back to neutral or park. Turned out to be due to him not wiring in the inhibitor switch correctly, so strange things can happen.

[sideshow]

when doin a conversion its usually easy to figure it out cause alot of the crap is gone

but when the car is stock std and it has so many shit in it it could run the space shuttle then its a pain in the ass to find the faults

thats y u will not find the answer on the internet cause if someone had the same prob they would have told u

unless the person is me and dont give any information out heheheheheheeh

[bansheebuzz]

buttocks - where in QLD are you located?

[Buttocks]

Sunshine Coast, Maroochydore

[oldcorollas]

stop stuffing aroudn with diagnostic machines

borrow a scope, stick it on the injectors, see what happens to the pulse width at that rpm.
stick the scope on each sensor and output and see what happens.

are you SURE it is not a mechanical problem... like busted valve springs or fuel pressure reg or....... check compression, take rocker covers off and check all bits work properly,
check ignition timing, check everything...

measure all the things going into and out of ECU, and measure fuel pressures.

there MUST be some physical reason why it is cutting. you just need to measure things to find out WHAT it is.. and then you can start to speculate as to WHY it is happening....

unless the person is me and dont give any information out heheheheheheeh

KM nitteiru ne

[Buttocks]

No not mechanical. I've owned a couple of SC400's and this one is as powerful, as smooth, and as quite as any of them. Its a rev cut at 3800rpm nothing else is wrong with the car it is absolutely faultless
As someone said before, i really need someone thats had the same problem
It will be something stupid that has been overlooked as everything major has been checked

[Hen]

Sorry, posted in wrong thread

[oldcorollas]

No not mechanical. I've owned a couple of SC400's and this one is as powerful, as smooth, and as quite as any of them. Its a rev cut at 3800rpm nothing else is wrong with the car it is absolutely faultless
As someone said before, i really need someone thats had the same problem
It will be something stupid that has been overlooked as everything major has been checked

ok, so whats going wrong?

you have three things to check.

air
fuel
spark.


usually, unless you have some whacky traction control thing happening, you can rule that out.
fuel- MEASURE the output to the injectors... measure the fuel pressure (both at the time of the cut) and SEE what is happening. if there are no problems, you can rule fuel out.
spark, MEASURE the timing at the time of the problem.. does it change strangely? does it break down?

once you sort out the above, you can go to next step..
without actually checking what is physically happening to the engine (as opposed to checking plugs and changing components) you are pissing in the wind so to speak...

edit:
you say you have "rev cut".... you mean you have a spark cut? does it retard or drop alternate sparks? or is it fuel cut? does it cut back and lean? or drop totally or??

[beasht]

This might be a very simple suggestion but I was having the same sort of problem as you. My 1j was popping and breaking down at around 4k then if really pushed hard it would just cut out like a hard boost cut, but when driving normally the car would drive great with no problems at all. It turned out to be the fuel filter was blocked as a result of me driving for a day with less than a quarter of fuel in the tank. Until I changed the filter I had checked the spark plugs and coil packs and it made no change.
So yeh you've probably tried alot of things and it's not going to hurt to put a new fuel filter in if you havn't already

[sideshow]

maybe u can get a video of it and we can download it and see what its doin heheheheeh

tryin to diagnos that sort of prob over the net or even phone is fukt hehehe

especially if you dont know what yr doin

[Buttocks]

I don't know if a few of you guys have ready the whole thread. Its not breaking done at 3800rpm its a proper rev cut at 3800rpm like the computer is in a valet mode or a feeble limp home mode

[sideshow]

ive read enough of the thread and gave up on it

anyway ill be in sunshine coast 8th till 16th nov working then goin on holidays after that

if u drive past me il give u a wave heheheheheeh

[Vios-GT_07]

I don't know if a few of you guys have ready the whole thread. Its not breaking done at 3800rpm its a proper rev cut at 3800rpm like the computer is in a valet mode or a feeble limp home mode

well mate u've just answered your question.. it's the computer... ?

if it is properly cutting at 3800 rpms.. then the ECU is at fault because it's suppose to cut at a value double that.. rpm signals going to your ECU ok?

with the vague info there is, i'd just be looking at the signals going in and out of the ECU.. obviously the injector pulses and everything is right.. then again if the ECU is getting a high rpm signal, it'd be running ubber rich with heaps of timing even though the actual RPM is low..

there are some suggestions here that u haven't exactly replied to, and said if u've done it or not.. e.g. fuel pressure, timing values as it's revving up.. etc etc... try them and let us know what's going on so we can rule them out and suggest other things.. oldcorollas is a guru so i'd suggest u take note of his suggestion..

unfortunately the only diagnotician that might solve ur problem is an import specialist in Victoria.. but for the cost to bring it around u may as well just rewire the entire engine loom, engine and ECU...

erm i just had a thought.. is everything in the fuse boxes all there and where it's supposed to be?

[Buttocks]

That import specialist in Victoria wouldn't happen to be Craig dean at Sports and Luxury cars by any chance?
And i'll double check the fuses box just to make sure

[Vios-GT_07]

erm.. no...

Nandi's autocare, in Dandenong area.. i think they're under the keysborough locality.. he's one bloke that can diagnose shit that the dealer can't find, on more than 2 occassions, and that's when i happen to walk in and see him do it...

oh erm... a mate has just told me that high powered cars like the SC400 are allowed to be test driven when new in a "test-drive mode".. could this be that case where the ECU is deliberately limped so tyre-kickers can't do shit to it? maybe it doesn't apply but i wouldn't to this but i wouldn't know.. just a thought