st185 - Boost Cut??

[FoRsaKeN]

Hey there guys
I recently got a boost conroller put in my car
And when i raise the boost to just under/around 12psi, the car kinda jolts (like breaking) and the engine check comes on....
Is this the boost cut??? or is my boost gauge so far off that i'm hitting the fuel cut that's meant to come in around 14.5psi???
Isn't a boost controller meant to stop boost cut???

Thanks

[CozmoNz]

No, boost controllers dont cut boost cut, unless you wired it directly into your ecu.

wish it was that easy.

at my guess, your boost cut is 12-13psi, and ur running 11-13psi... thus the juddering... sort of cutting but not maybe?

wut sorta car u got?

[fivebob]

wut sorta car u got?

Another classic CosmoNz post, you can't really be that stupid can you???

To answer the original question, that's overboost fuel cut coming in at approx 12psi, either lower your boost, fit a Fuel Cut Defencer (FCD), or disconnect and plug the line going to the MAP sensor from the manifold. On Gen II 3S-GTEs such as your ST185 it's only used for fuel cut, and to run the stock boost gauge.

[AJz]

wut sorta car u got?

Another classic CosmoNz post, you can't really be that stupid can you???

lol, opps

[peas]

I'm about to do the same thing. Though I have downloaded some instructions on how to manufacture a $15 FCD using a potentiometer and a few resistors if you want them. I have searched for it on the net but can't find it anymore unfortunately. It also details which wires need to be tapped but this is for a SW20 so I'm unsure if it would correspond to a ST185. Then again plugging the manifold-MAP sensor line sounds cheaper still but you lose the protection that the fuel cut provides... if that bothers you.

[matt dunn]

I'm about to do the same thing. Though I have downloaded some instructions on how to manufacture a $15 FCD using a potentiometer and a few resistors if you want them. I have searched for it on the net but can't find it anymore unfortunately. It also details which wires need to be tapped but this is for a SW20 so I'm unsure if it would correspond to a ST185. Then again plugging the manifold-MAP sensor line sounds cheaper still but you lose the protection that the fuel cut provides... if that bothers you.

If you dont want to loose the boost cut but just move it,

Cut the signal wire and put an in-line diode in it,
It will drop the output signal by abou 0.5 volt so will let it run higher before it cut's.
You can actually add two or three in line one after another and step up the cut each time.
They are only a couple of dollars each too.
This will work all the way up to the limit of the stock sensor.

Matt

[CozmoNz]

wut sorta car u got?

Another classic CosmoNz post, you can't really be that stupid can you???

To answer the original question, that's overboost fuel cut coming in at approx 12psi, either lower your boost, fit a Fuel Cut Defencer (FCD), or disconnect and plug the line going to the MAP sensor from the manifold. On Gen II 3S-GTEs such as your ST185 it's only used for fuel cut, and to run the stock boost gauge.

Bugger off, that said "boost cut" when i first saw that post. NOT st185

and his signature, well... i dont read them.

shit happens.

[FoRsaKeN]

Oh ok, so it's the fuel cut... i thought that comes in at around 14psi, but i guess it varies aroudn the world..

A diode in the MAP sensor line??
Yea, i wouldn't mind raising the fuel cut by a little bit....1 diode raises it how many psi, you know???
is that the only reason why the st185 has a MAP sensor and Air Flow Meter as well?? Cuz the MAP sensor initiates boost cut???

thanks for the help guys

[matt dunn]

A diode in the MAP sensor line??
Yea, i wouldn't mind raising the fuel cut by a little bit....1 diode raises it how many psi, you know???

Not 100% sure as it varies from model to model.
Fit 1 and try it, or 2 maybe.
but i guess that you'll ned about 3 in series to add a decent level like another 4psi.

Just a note to others who read this too,
You cannot do this mod on a vehicle that is MAP sensed only!
You can only do it to the ones thatr run a map AND an AFM

Matt

[FoRsaKeN]

Cool, i'll give it a go, after i do a bit more reading on it...
it's not giving me too much troubles at the moment.

Another question, i'm guessing the fuel cut comes on when it recieves a certain voltage from the MAP sensor.
So does this mean it's an ALL OR NOTHING effect???
Because if it isn't, and my boost controller is set to just below the fuel cut psi, i don't want to be running lean the closer i get to the fuel cut threshold

[Lanius]

wut sorta car u got?

Another classic CosmoNz post, you can't really be that stupid can you???

To answer the original question, that's overboost fuel cut coming in at approx 12psi, either lower your boost, fit a Fuel Cut Defencer (FCD), or disconnect and plug the line going to the MAP sensor from the manifold. On Gen II 3S-GTEs such as your ST185 it's only used for fuel cut, and to run the stock boost gauge.

Bugger off, that said "boost cut" when i first saw that post. NOT st185

and his signature, well... i dont read them.

sh*t happens.

I'm finally hooking my boost controller back up this weekend, will be interesting to see how the RC bits respond with a standard 185 ECU controlling everything.

Forsaken ... what kind of boost controller have you had fitted?

[Al]

i don't want to be running lean the closer i get to the fuel cut threshold

You wont ever run lean on the stock turbo.

[Lanius]

i don't want to be running lean the closer i get to the fuel cut threshold

You wont ever run lean on the stock turbo.

Al, you've done the disconnect-pipe-from-manifold-to-MAP-sensor trick on your 3S, correct? Mind posting a couple of pics of it?

Cheers

[Al]

Well its so simple I dont think it even warrants taking a pic.

Just pull the hose out of the boost pressure sensor (map sensor) and then either plug it up or remove it entirely and put say your boost gauge line into the manifold where the hose used to go.

[FoRsaKeN]

Lanius : I've just put in the dual stage hybrid electronic boost controller Type Ii

Al: Disconnecting the map sensor completely and hooking up the boost gauge there.... i'm guessing that would eliminate fuel cut as well?? And give an accurate reading for the boost gauge?? any ther 'side effects'??[/quote]

[Al]

The only side effect is no boost cut at all.