sc400 Rev cut a 3750 RPM HELP URGENT

[Buttocks]

Do you have anymore info on this test drive mode as someone has said something similar before.

[oldcorollas]

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

i read the whole thread.
what do you mean "its a proper rev cut"
there is no such thing as a rev cut it's either spark cut or fuel cut... and this acts as a rev limiter.

check which one it is, and compare that to how it should behave.

you said you already changed the ECU... so it must not be that. no??

until you actually meaure things, you are just guessing that it has a rev limiter thing happening..

you can either keep guessing in the dark.. or you can check what is physically happening.

[Buttocks]

Ok dokie will do

[sideshow]

test drive mode
never heard of it on jap cars
maybe only wrxs

anyway has the car ever run good
did this just recently happen

if so then i dont think its in test drive mode

maybe try disconnecting battery overnight to reset things and see what happens

i offered to look at it and will be up that way in 2 weeks but now i wont be up that way long enough

i diagnose alot of jap crap cars too
thing u have to remember these ar eone of the worsts cars to work on when it comes to checking alot of the ecus under the dash/kickpanel etc area
they have alot of ecus talkin to eachother
abs ecu
traction/abs ecu
engine ecu
fuel pump ecu
cruise ecu
and many more
anyway he wants to fixx this prob himself otherwise the thread would not have wasted 4 pages and 10 minutes of my life hehehehehehehehe

[Vios-GT_07]

hm.. that's what i thought.. but apparently it happens on other jap and euro cars as well.. the limit can be anything from throttle limit, to timing and fuel...

yeh that's one of the things i dun get.. fuel pump ecu?? japanese must've gone mad at some stage and installed an ECU for everything.. even electronic dashes are one big chunk of mainboard..

anyway good luck with it mate.. take up the offer if someone can come have a look i say.. just to be sure.. i'm all out of ideas.. sorry

[MacroP]

Having a Soarer engine I can say that the fuel ECU can be bypassed and the TRC ECU can be unplugged without harm. You can use a good meter on the diag conn (FP) to measure the voltage going to the fuel pump and back to the engine ECU. A CRO would be better as it's a PWM signal. The Soarer engine has feedback from the Fuel Pump ECU to engine ECU. I guess if this signal is not correct than the engine ECU could force a cut to protect the engine maybe.

On a lot of Toyota's I've noticed you can bypass all the fuel pump control by putting a bridging wire from B+ to FP in the connector. I did noticed on this engine though the FP wire going from the diag conn to the main loom is very small so I would not recommend putiing a bridging wire in here. I don't think is could support the current needed to power the pump. Just use it to monitor the fuel pump voltage.

I have heard on Soarer Central that the Fuel pump ECU is a common fault though I can't remember how the engine ECU reacts to this.

Hope this helps.

[Buttocks]

I swapped fuel pump ecu's and bridged the 2 curcuits, i've done all the tests i can think of on the fuel pump side of things, think elsewhere. Whoever guesses the problem gets a Free Slab - Beer or Coke for the youngun's

[MacroP]

Does this happen when only driving or when free revving in both neutral and park?

So, just to clarify - The problem existed right from pickup, straight off the boat so to speak.

[Buttocks]

Yes the car has always had the problem since it was imported
And it hits the cut in everyway, N, P and in any gear

[CrUZida]

Have you checked the TPS yet?

All Toyota ECU's have a safety for a failed TPS.

A TPS is in IDL mode when there is no pressure on the throttle.
While the TPS is in IDL, the motor will not rev over a certain amount.

Its possible the TPS, and/or the wiring between the TPS and the ECU is faulty, and thus the ECU thinks the TPS is in IDL, and will not let it rev.

I'm not sure if this will affect the drivability of the car. I'd hazard a guess it would, and thus could possibly not be your problem. But its worth a check anyhow.

Test the voltages of the TPS pins at the ECU with it all plugged in, and see if the circuit between IDL and E2 goes open circuit when you put your foot on the throttle.


I doubt any diagnostics would pick this up, because most Toyota diagnostics require the TPS to be in IDL to work (such as the self diagnostics)

[Vios-GT_07]

Have you checked the TPS yet?

this might also sound pretty stupid but have you checked TPS and throttle cable??

i did suggest you this first.. *meh* if that's the solution.. me and cruzida.. we'll share this slab of beer.. i'm still waiting for him to come back from the north so i can do some "business" (CAR RELATED) with him..

[Sigmeister]

big hunch here, but what is the rev limiter set to on a 6 cylinder soarer?
on commos i think they get their signal from the dash/instrument cluster to a multiplier then to the computer. so if one changed an instrument cluster from between a 6 cylinder version to a v8 version the multiplier for revving the engine would be different.
this is no commo i know but it is just another theory.
debunk as required
good luck.

[oldcorollas]

measure the frickin inputs and outputs and you will find your answer

there is no need to guess.. just fix it

[madmont]

It has been suggested thet the Throttle Position Sensor may be at fault. What is the part number on the sensor closest to the manifold and the sensor on the traction control butterfly farthest from the manifold?

[sideshow]

i wouldnt get out of beer for a slab of beer
and by looking at length of thread its not goin to be that easy
id atleast want a very big bottle of jim beam

anyway im off to goto qld in few days to wire up 3 1uzs

if yr interested in fixing it then call me
maybe ill have my phone on if i can be fuct lookin at it
heheheh