Fuel Cut disable/delete??? ST185

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Fuel Cut disable/delete??? ST185

Postby Selsvik » Sat May 04, 2019 11:03 pm

im having trouble with finding out how to disable the Fuel Cut on my 91' ST185. i have a Fuel Cut Defender, but im not sure where to install it... i would be so glad if someone could show me in photo where to mount it.:)
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Toyota Celica ST185 AllTrac
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Re: Fuel Cut disable/delete??? ST185

Postby alltrac801 » Mon May 06, 2019 4:35 pm

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Re: Fuel Cut disable/delete??? ST185

Postby Selsvik » Mon May 06, 2019 6:54 pm

thanks for the reply! :) But isn't there an easier way to to it with some of the hoses that goes to the pressure sensor?
its just that i dont know exactly what hoses to connect to. btw, i have a turbosmart FCD :)
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Re: Fuel Cut disable/delete??? ST185

Postby underscore » Mon May 06, 2019 7:46 pm

Do you want to raise the fuel cut, or remove it entirely?
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Re: Fuel Cut disable/delete??? ST185

Postby Selsvik » Mon May 06, 2019 8:52 pm

Not sure, depends on whats easiest... If You know how to disable it entirely, feel free to share :) :)
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Re: Fuel Cut disable/delete??? ST185

Postby underscore » Mon May 06, 2019 9:17 pm

It's posted up in several places, but you just disconnect the hose running to the MAP sensor and plug it. This will disable the stock (useless) boost gauge as well.
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Re: Fuel Cut disable/delete??? ST185

Postby Selsvik » Mon May 06, 2019 10:09 pm

Thanks!!! :))) do you have any pictures of what hose this is? :)
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Re: Fuel Cut disable/delete??? ST185

Postby underscore » Mon May 06, 2019 10:18 pm

Not off hand, I believe the MAP sensor is mounted near the firewall, up top and in the middle.
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Build thread http://www.alltrac.net/phpBB2/viewtopic.php?f=44&t=44216
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Re: Fuel Cut disable/delete??? ST185

Postby Selsvik » Tue May 07, 2019 6:40 am

Is there any difference with this between Carlos Sainz and standard st185?
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Re: Fuel Cut disable/delete??? ST185

Postby Selsvik » Tue May 07, 2019 9:25 am

How does this sensor look like? :)
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Re: Fuel Cut disable/delete??? ST185

Postby alltrac801 » Tue May 07, 2019 3:35 pm

The MAP sensor bolts to the firewall and has a vacuum hose on the bottom side of it. If you google ST185 MAP sensor you should be able to get an idea of what it looks like. If you still cant find it let me know and I can send you a picture.
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Re: Fuel Cut disable/delete??? ST185

Postby EvilStig » Tue May 07, 2019 6:44 pm

I installed the FCD box on mine recently and have pics from then.

Image

This is the MAP sensor. Fuel cut happens when the voltage returned by the MAP sensor on one wire reaches 4.4 volts. The fuel cut defender works by reducing this voltage by a particular amount so the ECU reads a lower voltage than the sensor puts out. It's effectively a variable resistor.

Fuel cut is an important safety feature and I would not recommend disabling it entirely. You could blow your engine or manifold if you exceed around 15-17 PSI without supporting mods.

You will absolutely want an aftermarket boost gauge at least so you can keep an eye on your pressures.

More info on fuel tuning here: https://www.alltrac.net/tuning/fuelfaq.html
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Re: Fuel Cut disable/delete??? ST185

Postby Selsvik » Sun May 12, 2019 9:33 pm

Ok, so i disabled the Fuel Cut entirely by plugging both ends on the pressure sensor.
I have a boost gauge and an air fuel ratio gauge for safety, so i dont blow my engine.
But there is still something with the car... It doesn't like boost over ca 0,7bar(running on 1bar boost)
I dont know exactly what it is, but feels like it cuts the fuel or something.
The AFR gauge says 8,xx to 9,xx when i give full gas on third and fourth gear, so it runs very thick... And when it idle, it runs on ca 15,xx 16,xx.
Can this be what causing the troubles im having?
And btw, when i disconnect the battery for a little while, there is no problem with running 1bar boost...
Could it be something with the ecu not liking this?

Specs:
3" downpipe De-cat from gt4-play. Rest of the exhaust is original
Turbosmart boost controller - 1 Bar boost
Turbosmart boost gauge
AEM air fuel ratio gauge
POD Filter
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Re: Fuel Cut disable/delete??? ST185

Postby underscore » Sun May 12, 2019 10:17 pm

Sounds like you're overfueling under boost and a little lean at idle. Do you have any intake or exhaust leaks?
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Re: Fuel Cut disable/delete??? ST185

Postby Selsvik » Mon May 13, 2019 7:43 am

Not that i know of... Will check later! Where on the intake would this be a problem? Before or after the turbo? Because the hose before the turbo has a crack in it.
And i think i got the exhaust tight when i changed the downpipe, or else i would have heard it. The lambda sensor has been changed as well, so that should be ok.
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