Fuel cut problems.
 

I have 92 gt familia which was origanaly an 1800doch non turbz but i have droped a bpt motor in and have recently put a fmic on it.i now have problems with it cutting out when im on full throttle which is 13 to 14psi so im guesing this is the ecu fuel cut?? im after some suggestions on overcoming this any help will be much apreciated..

fuel cut defender

aftermarket ecu.

if you are using the vj20, then you ain't gonna gain much power over 12psi, so it shouldn't bee too much of a problem if you set the limit at that psi...

ryan

is there anyway i can set the boost at 12 pound without going for an aftamarket ecu like a softer wastegate spring or something?

Check that you have no air leaks between the turbo and the wastegate actuator.
Add restriction to your exhaust.

use whatever you are using to get it to 14psi. i'm assuming you have a boost controller of some sort as manufacturer spec max boost is 7.2psi.

No i dont have a boost controler.just have a 2 1/2 exhaust and the front mount was fine till i put the frount on so must have a boost leak im geusing??

yeah as cosmo said, a leak somewhere then.

ideas on how to find a leak?

first thing to do is look at the air pipes to see if you see any obvious cracks.
Otherwise you can rub soap water over the pipe and look for bubbles.

But as mentioned - you shouldnt be reaching 13-14psi with a standard turbo and a FMIC. Boost should only reach the standard with tends to be about 7-10psi.

Are you getting that high reading from a boost guage ?

yer thats what i thort.yep it is kuming from a gauge.Ive noticed today wen i was driving it that it sometimes cuts out below 10psi aswell not just up around 13

if its reaching that high then the boost controller must not be operating, or the wastegate flap is stuck.

did you hook up the boost control's small vacuum hoses after fitting the FMIC ?

there should be one that comes from after the turbo and goes to the wastegate actuator and boost controller ( with a Y splitter ) and then from the controller valve back into the intake, before the turbo

I dont hava boost controller so must be the wastegate.Il check that out and see wea that gets me.cheers alot.

Not even the standard one ?

Even without a boost controller there should be a vacuum hose running from after the turbo to the wastegate actuator.

There isnt any 'stiffer spring' for the wastegate actuator - its a sealed unit.

Not that i no of.where should i find it and what duz it look like?

Pictured below is a turbo with an inbuilt wastegate.
The thing on top with the barrel and the shaft is the wastegate and it's controlled by the pressure between the turbo inlet side. It opens a gate in the exhaust section which limits the boost by by-passing exhaust gas around the exhaust turbine.
http://images.sportcompactcarweb.com...vf23_turbo.jpg
There should be a hose between the wastegate actuator (shown in blue) and the boost side of the turbo. Any leak in this hose can cause over boost.

Ive just tightened the hose clamps on the actuater hose and all the intercooler piping and took it for a drive.the boost is now back down to about 11pound and it went fine for about 5min then it started cutting out agen on higher boost.I think i could posibly have crook injectors because it takes a while to start the car when its cold,would buggered injectors cause the cutting out??

how are you running higher boost than stock without a boost controler???
i dont understand even the cheapest version(T-valve) gives you a option to run lower or higher boost. if you do not have a boost controler than you have a leak somewhere deffinately

yea musta had a leak somwea cos checkd over all piping clamps ect and now only boosting around the 10 and 11 mark but stil having problems with what i think is fuel cutting or shortage posibly.

stock BPT ecu has a flow cut of 14.7psi.
if your running a bigger turbo than the cut level will be lower,
e.g a VF10 = 12~ psi
if you haven't butchered the Jspec ecu then your rev cut will be at 5500rpm

Fuel Cut defenders won't work in this situation as most of the time they require a map sensor which the BPT does not have.
if you are getting cut outs at 11psi~ and your running the stock turbo,
definently check for leaks and also check to see how much fuel flow you are having.