Boost cut st185 - boosting problems

[CelicaGT8]

How would one go about stoping the boost cut on a st185? want to run 14psi.

[Malcolm]

pull the hose off the map sensor and plug it up

[Akane]

Or a zenier diode installed if you just want to raise the boost cut, but boost cut is for pussies.

[Malcolm]

zener diode doesn't raise it, it eliminates it.

[Akane]

zener diode doesn't raise it, it eliminates it.

My bad, it does too.

Since ST185 does not have an awesome factory boost gauge like you get on the MR2, might as well rip the hose out and plug it up.

[Heylin]

Yep rip that hose out and plug it up, I ran like that for 3 years without any issue. Using GFB atomic manual boost tap set to 16psi.

[Malcolm]

Since ST185 does not have an awesome factory boost gauge like you get on the MR2, might as well rip the hose out and plug it up.

yes it does

want to make any more statements for me to correct?

[CelicaGT8]

Im not runing the map sensor... so no line to unplug, its not there, still has boost cut tho

[Akane]

Since ST185 does not have an awesome factory boost gauge like you get on the MR2, might as well rip the hose out and plug it up.

yes it does

want to make any more statements for me to correct?

WTF

Last time I took a ride in tranquil's car 4 years ago, I swear it didn't have the awesome boost gauge.

Maybe his car was a conversion from a 182........ lame.

[Malcolm]

Im not runing the map sensor... so no line to unplug, its not there, still has boost cut tho

plug the map sensor back in but don't put a hose on it. Without the map sensor it calculates boost cut from AFM signal and engine RPM, the same as how ST165s did it IIRC

[Malcolm]

WTF

Last time I took a ride in tranquil's car 4 years ago, I swear it didn't have the awesome boost gauge.

Maybe his car was a conversion from a 182........ lame.

If it was converted from a 182 it would've been FWD and shitty, more likely that the gauges had been swapped or something. Or you're just blind.

[CelicaGT8]

Cancel that.... i acuhally do have it hooked up, i had it hidden
But it makes no difference if its pluged in or not nor when it has a pipe to it or not...

[Malcolm]

is it possible it's not wired correctly, or is faulty? Plugged in map sensor with no boost line to it = no boost cut on a ST185 ecu, but if for some reason the ECU is ignoring the map sensor, either due to a fault or it being disconnected, then you will have boost cut.

If you're certain the wiring and sensor are good, plug it in, reset ECU and try again.

[CelicaGT8]

Hmmm, il try another one, think the wirings sweet, will check after trying another one, are they the same as NA ones?

[Malcolm]

They'll be different to the na ones I suspect, you could however just wire in a variable resistor of and appropriate impedance(not sure what would be appropriate but I can measure mine if you want), and set it so the centre pin outputs around 2-3 volts

[Akane]

If it was converted from a 182 it would've been FWD and shitty, more likely that the gauges had been swapped or something. Or you're just blind.

Maybe, his car was a bit of a frankenstein, RC this, 185 that, no heat exchanger for the w2a......

[CelicaGT8]

Changed that map sensor today, put an sw20t one on, and it looks totally different, its not hitting boost cut now, but theres another problem, unrelated to the boost cut...

When i get boost, it sounds like its back fireing, or missfireing or both haha, wont get more than 5psi boost, goes good untill you get boost, you can slowly speed up without getting boost and it will run fine, but when you do put your foot down a bit it runs like total crap, no fault code that relates to this...

knock sensor is fine... Fuel problem?

[iOnic]

AFM/Boost leak?

[Malcolm]

almost guarantee it's your leads, seen it in so many ST185s and SW20s. Ideally you should probably change all the ignition system bits - plugs, leads, cap and rotor - but at the minimum get some new leads