microbg

Alright, so a bit about my self and what i'm running.
I'm Michael Price and i love going fast.
i have a scion xD and i recently installed a T3 T4 Turbo. i have a waste gate, intercooler and BOV.
I also have a FMU and TC stock injectors.
i'm planning on running 6 pounds of boost but my MAF (mass air flow) sensor seems to be cutting me off.

what can i do to resolve this problem? i'm not leaking, turbo is spooling, and sounds great! but when my boost guage hits 1PSI my MAF sensor shuts it down to idle. does not seem to like the boost. i have the MAF sensor in front of my turbo. i can drive fine, but if i try to get on it and go.. just blocks it out..

can i trick my MAF?
or is it not even a MAF related problem.
no one makes a piggy back for my car so i cant get emanage and all that...

Please help. i have 2.500$ under my hood and all its doing for me so far is making cool sounds... i want more then just the Spooling sounds teasing me...

Carlanga

u don't need a car specific piggy back, u can pretty much use anything (e-manage, fic, etc). There might not be a boomslang harness if that's what u mean, if that's the case u might have to take it to a shop for them to hard wire it to ur ecu and that's it.

microbg

this normally an expensive ordeal?
my friend is willing to sell me his e manage for 275$
but there's no wire harness for my car. so i guess it would need to be hard wired..
and tuned?

sounds our of my current budget =(

TRDxD

You've obviously gone in a little over your head...if you can't tune for your boosting you're pretty much screwed...I agree with Carlanga, take it to a shop and get it done properly.

DeathMachine

I just read your post on the other thread. IF thats where your MAF is then move it to after the turbo and see if that helps.

The xD can't "sense" boost since the compter it comes with wasnt pre-programmed and installed with a MAP sensor. All it can do is sense how much air is traveling past it and at what velocity. Technically, where you have the MAF now is the most effective. I think something else is wrong, cause I've never heard of a MAF sending your engine back to idle because it is getting too much air.

I'm with TRDxD, you may have gotten in a little over your head. Did you do much research before you decided to go turbo?

Either way, DEFINATLY take it to a reputable shop and have them evaluate and tune your car. Yeah, it may be out of your current budget, but if you're serious about doing it right you may need to re-evaluate your budget...

microbg

i can get a tune. but i need to wait about 4 pay checks.
the car runs fine i just cant floor it. i know the sensor is blocking it out i'm just wondering if there is a way to trick it like hondas do with the "missing link" adaptor
if so, id much rather do that for a low boost setup. if not ill just wait 2 months and drive like every one els on the road till i have the cash for the tune =/

microbg

i have heard that some people just upgrade the MAF to one that can handle more power? or will it still have the same effect as the current setup.

microbg

FCD perhaps?

Carlanga

I don't mean to be rude but, sad to say I don't think u have the faintest idea of how a turbo works. There's no honda tricks here man. I haven't seen ur other thread to comment on MAF placement and don't know the capabilities of the xD.

I know some folks used to run tC's on low boost and no engine management, one of them being a buddy of mine and he ended up blowing up his engine. Take it to a shop and get it hard wired and tuned. They could even do a blow-through set up if ur worried about stalling and correct air readings.

GL

misformartin

wow........ this blows.... you def need to get it tuned .... have a reputable shop hardwire a piggyback into your car..... i dont recommend running it with no engine management as maybe invest in a wideband to check af ratio to make sure your not leaning it out to much at open throttle...

TRDxD

x10000000000000000000000000000000000000000

pickledchang

sounds to me like you are leaning out... i would definitely try the MAF on the other side of the turbo first, and get a wideband. if you can, make sure your not pushing the duty cycles on those injectors either, even though you shouldnt be with the larger ones.

WellesleyScion

I dont quite understand where your MAF is currently placed... infront of the turbo could mean a lot of places... is your MAF on the intake pipe that connects to the inlet pipe of the turbo? OR did you put it on the hot pipe inbetween the oulet pipe and the intercooler?

If you have it on the hotpipe that is why your getting the cutoff... what is happening is the boost is building pressure in the intake stream to the manifold, and making the sensor go "WTF IS GOING ON!?!?!?!?" and your ECU is responding with "CUT THE FUEL BEFORE YOU BLOW UP!!!!!!" BTW, the technical term is called fuel cutoff...
When you have the MAF on the intake stream to the turbo, you dont create pressure in the pipe, and the sensor goes, "WOW its windy in here, send more fuel" and the ECU goes "here you go"

misformartin

actually might be hitting the duty cycle of the those injectors... it think the xd injectors are 300 cc and the tc are only 360 cc so you might have an issue with not getting enough fuel..... which case you will be running really lean.....dont blow your engne : (

pickledchang

lol, thats the similair to the story i was going to tell, but im not quite sure where his MAF is... the MAF cant really read pressure, so it will have trouble if its after the turbo and you dont have a tune. however, if its before the turbo, it will be reading the near atmospheric pressure that its used to moving at a high speed... instead of pressurized air moving at a lower speed if it were after the turbo.

off the top of my head, the MAF only measures temperature and velocity then combines that with the known diameter of the intake piping to calculate the amount of air coming in. if its on the hot side of the turbo, its going to think there is less air because its moving slower (because its pressurized) and its hotter (so it thinks the air is less dense).

micro, can you kindly draw us a schematic or something to show how your setup is put together?

DeathMachine

No offense to you Micro, but I think you need to take the turbo off of your xD before you blow the thing. Leave it off until you can afford a tune. And please keep in mind that its going to be a very expensive tune because you're not tuning just a VVT-i, its Dual VVT-i and almost no one knows how to tune those properly yet, since the 2ZR-FE is the first engine in America with it (with the exception of a Lotus).

And while its off, do some more research. I think you know some, but not all, of what you need to know to be boosting. You MAY be hitting the duty cycle of the injectors, but I don't think thats going to knock you down to idle, if anything you'll burn the injectors up. And if it were a MAF problem, I'm leaning towards that you're engine would shut down, not just return to idle.

But definitely, if you aren't going to be tuning it for at least 2 months, be safe and take the turbo off. It seems like you're having too many issues for it to be safe to have it on untuned...

WellesleyScion

Ok I read both this post over and the other one you posted on.

Whats the rising rate the fmu is set to? range should go from 1:1 to 4:1 you dont want it to be higher than 2:1, my guess is that your running super rich and thats why your bogging out once you hit boost... If its set to say 4:1 your fuel pressure is being bumped 4 times what ever your boost is hitting... so 4 times the amount of fuel at 1 PSI is more than enough for you to bog out. As a side note, if you have the rising rate too low your car will pull through the gears, but when its at the top end its going to have detonation, which is the leading cause of blown engines in turbo applications...

also the issue you have with the smoking is caused because of 2 possible reasons, one is that the turbo is mounted too low and oil is unable to reach your oil pan which is clogging the line and being forced into the engine itself.
The other scenario is that when you tapped the oil pan you tapped it too low and again its not draining out because the oil in the pan itself is blocking the flow causing the same situation...
So to fix that issue you want the oil return line to be tapped into the oil pan at the top, and you want to ensure the line itself is going toward the ground(so gravity is pulling the oil down), if the oil line curves back up in any way your going to run into the clogging issue...

And BTW, DO NOT remove the turbo, your doing good so far keep at it and be careful and conservative with everything you do and you will have a turbo xD without any issues =D

NIVO88T

your MAF is not the problem until it gets maxxed out (voltage wise).

Seems that your FMU is the problem and without an actual Airl Fuel wideband monitor you petty much have to stop where you are at now.

Did you study anything on turbocharging a vehicle?
Is your turbo ball bearing? if it is you might need to tone down the pressure to the CHRA. Use an oil restrictor regardless of what others may tell you. Only if it is a true DBB turbo.

Most Turbo cars today, from the factory use timing as their "fuel cut off", it is a term that has been misused for a long time. Fuel cut off wouldn't make sense if you were boosting 16psi and all of a sudden there was no fuel because the computer said "oh too much boost".

You don't have any safety devices as the computer is blind to the boost, it doesn't have an actual "fuel cut off" for boost. What it may have is fuel cut of or timing cut for red limit. And that is about it. if it is a soft stop at rev limit it is possibly timing being backed off, if it is an abrupt stop then it is the computer shutting the injectors down.

Like Wellesly Scion said, For your other issue look into your draining of the turbo, oil restrictor if it is a dual ball bearing turbo.

A FMU is adjustable, 1:1 means that for every pound of boost the fuel pressure raises 1 pound. 2:1 is the same but the fuel pressure raises now by 2 pounds for every pound of boost. and so on.. FMUs are basically what I call "My first tuning module", very crude at best. you are possibly flooding the engine with fuel but you can't do much until you know what you have for an air fuel ratio.

pickledchang

i would do three things as soon as possible:

-move the MAF before the turbo
-get a wideband o2 in there
-figure where the FMU is set at

and if possible, check the duty cycle on the injectors, if youre over 85%, youre really starting to push it. its hard to say if youre leaning out or flooding it without that wideband in there.

YELOSUB

have f/ic hardwired and get a tune....