The boost cut function

Of my ECU decided to start working again today. I am sad.

Kindof went like this:

Oh look! Onramp with tons of open space!

20mph, 2nd gear, HAMMER DOWN!!!!

baaarrrrffff(-10inches)fwwwhoooooooossshhh(0ps)pspssssshhhhhhhh(17psi)PUH! then nothing.... BEEP!!!! (shut up car.)

Arg. Thanks, car.

I am held to a lowly 10psi. I have traction in 3rd. This is boring.

can you disable it?

With a chip, yeah, or Megasquirt. Not real sure which direction i want to go at the moment.

Thinking a chip, crank the AFPR, and mess with base timing should be fine, cheap, and not have to deal with electronic hassles.

sweeet

Can't you bypass the OE boost reference sensor?

John Brown wrote: Can't you bypass the OE boost reference sensor?

Maybe? I don't really know. I'm a Toyotard, not a Maztard.

I know i could screw with the VAF to get some more room, and even "tune" for the injectors to not run so rich, but that scares the bejeezus out of me.

The chip is $40, i'll probably just go that route.

at 10 psi of fun, why haven't you yet?

Wait... $40.00?

I will not laugh at you on the internet like I am laughing at you for real ;)

figure out what the voltage signal is at the boost pressure switch when it sends the cut out, modify signal so it doesnt

Find out why it wasn't working before. Repeat.

the ecu uses the vaf meter to tell if you're injesting too much air. in my (short) experience, the bell wouldn't go off unless it was due to a intake leak. i had a leaky wastegate line that would let the turbo overboost and it wouldn't set of the dinger. only time that went off was when the L-pipe straight off the turbo had a crack in it.

Strizzo wrote: the ecu uses the vaf meter to tell if you're injesting too much air. in my (short) experience, the bell wouldn't go off unless it was due to a intake leak. i had a leaky wastegate line that would let the turbo overboost and it wouldn't set of the dinger. only time that went off was when the L-pipe straight off the turbo had a crack in it.

Hrmm... possible i guess. But whenever i've had an intake leak with this car, it just won't run at all, and if i start blowing out an intercooler pipe, it'll actually completely die on me, instead of just cutting out like this and continuing on it's way. I run all hard pipes and t-bar clamps on this car. I checked it pretty good yesterday and it's all fine.

Keep in mind that with the stock turbo, you could definitely spike up to 15-16psi and it would be fine up to at least 4k rpms without cutting out. But i'm also running a turbo capable of easily twice the flow of that. I, and everyone else, are honestly surprised that it doesn't cut at like... 7psi.

did someone already do the screw mod inside the VAF? also, one of your couplers could be leaking only under boost, but not under normal conditions?

when mine was spiking, it would cut at 14 pretty much every time on the stock turbo. not sure why you wouldn't be cutting with your turbo and no chip.

Strizzo wrote: did someone already do the screw mod inside the VAF? also, one of your couplers could be leaking only under boost, but not under normal conditions? when mine was spiking, it would cut at 14 pretty much every time on the stock turbo. not sure why you wouldn't be cutting with your turbo and no chip.

The VAF appears to be unopened. I highly doubt that my couplers are leaking, BUT, i do have an el-cheapo ebay BOV on the car at the moment, and i know that thing leaks slightly. I can hear it even at idle. I'm sure that's not helping things.

Might I suggest a recycling BOV temporarily, to see if it goes away?

John Brown wrote: Might I suggest a recycling BOV temporarily, to see if it goes away?

I would if i could do it for free or near free, but i can't. The car is a freak in more than just it's previous lack of boost cut. These things SHOULD stall when using a vented to atmosphere BOV, but this thing doesn't. It's slightly slow to build boost between shifts, but that's a good thing in this case, and i'm sure it'll speed up some when i ditch this POS that i'm using now.

For what it's worth, it's leaking bad enough at idle that if i put my hand over it, the idle DOES change.

I'm just waiting to take care of the Escort clusterberkeley right now before i get the rest of the parts i need to put a Turbosmart BOV on there.

Errr... i mean: BOV makes a PSHSHHHHHHHHHHAWWWW noice and it's jdm tyte!

Aquarium valve to bleed the signal to the BOV? or was it the wastegate? dunno seemed popular at one point with the DSM guys.

Spinout007 wrote: Aquarium valve to bleed the signal to the BOV? or was it the wastegate? dunno seemed popular at one point with the DSM guys.

Eh, the BOV besides the leaking isn't an issue here, i don't think. I don't think the car is doing anything WRONG, i think it's just finally acting right, and my main purpose of this thread was to vent. I liked it better when it was wrong.

i think the ecu can tell if you have a leak between the air meter and the throttle, which is why you have the dinger going off. the dinger "typically" doesn't go off because of overboost. can you take apart and check your crap BOV? the o-ring on some folks forge valves dried up and caused them to act funny. some white grease and they were good to go.