Hi, my 99 Uk Impreza has had issues since I've owned it due to fuel cutting when overtaking etc.

I spoke to a Jap tuning specialist/rolling road place earlier and they suggested I could do with a Boost controller as my my has been decatted and this may be causing my issue.

Since I'm new to the world of boost controllers, does anyone know if the Greddy Profec B that he suggested is any good? Are there any better ones around the same money £200 ish?

Also, is it worth me having an uprated fuel pump fitted at the same time or can it be fitted fine without that supporting mod?


thanks

 

you really want a remap of yr ecu as you have decat the exhaust , boost controller wise the Apexi AVC-R(£200-300) is the best on the market at the moment.
fuel pump is always good as an fuel regulator (laying the foundation for future power hike )
speak to your tuner , he will advice you best (if they are any good ! )

good luck ...as you will need it

 

Thanks for the help mate. I'm not sure on Impreza's but I think there are 2 cats and the one on the downpipe has been removed but the other one has been left in.

A remap would be great but funds don't allow at the moment unfortunately. also if I had it remapped I think I would want to go the full hog and have a larger turbo put in then remapped. - maybe in a couple of years :-)

I heard that maximum boost is 1bar on my model so I'm hoping if it's set correctly by them, I shouldn't get fuel cut off again

 

I think you should have it inspected by a good Subaru specialist , yr car is cutting out for a reason ,they will advice you much better than us on the forum , mind you you must find a good one first !!!

 

The garage I'm taking it to is supposed to be a specialist of Subarus and Mitsubishi Evos and were recommended to me so I'm hoping they'll be good. They're going to run a diagnostic check on the car, then check it on their rolling road.

Just wondering if an uprated fuel pump is necessary if I'm getting a boost controller or if it's something that I can always get done later on?

Am I right in thinking that a boost controller will only allow boost up to whatever the ECU says. Therefore I don't have to worry about turning a dial and accidentally whacking it up to 2 bar

 

.09 bar on MY99 and 00 as far as I know mate.

And no, AFAIK the controller takes the boost away from the ECU so no ramping up that boost manually!!

Ns04

 

fuel pump and such mods can always be add at a later date...best to do all planned mods just before mapping time though

 

great thanks. a remapping will definitely be on the cards at some point but more than likely not for a year or so, then I'll be going for a larger Turbo and remap to hopefully break 300bhp.

In the meantime I'm hoping the Electronic boost controller will fix my short term problem of Fuel cut under hard acceleration and hopefully it is the cause of my Check Engine light flickering.

Is it also possible that an electronic boost controller on a non remapped car can increase performance if the boost is regulated better?

 

Unfortunately, mine is doing the exact same at the moment.

It started when I removed the manual boost controller and re-connected the standard 3 port boost solenoid back in the system. I've yet to check pipes for poor fitting or cracks between the boost controller and turbo actuator which has also been a suggested cause on other threads.

Mine has a full decat, Apexi induction kit, everything else standard engine wise. I may be fitting the manual boost controller back in as like you say, overtaking is a complete hit or miss affair

Needless to say, I'll be watching this thread closely

 

Good luck with the fuel cut problem NuttyNick. It's a pain, but I'll keep this thread updated when I take it in for: diagnostics / rolling road / electronic boost controller is done on Thursday this week.

I did consider a manual boost controller too due to their price, but I'm going to opt for an electronic one such as the Greddy Profec B as it's liekly to do a better job.

 

Totally agree I've seen the result of Manual Boost Controllers on Renault 5 GTT's - not good. I was thinking of getting an electronic contoller myself as the remap is a little ott price wise atm.

 

if yopu can aford it go for the apexi avc-r as that is the best boost controller on the market , also it has a in-car display unit which you can adjust boost along with 2 switchable map mode , it is only £30-50 more than the Greddy , but with much more features all the guys "in the know " have one !!!
downside is if yr not capable to set it up , you'll need the tuners to set it for you (more expense ), but its a gr8 piece of kit, I have it in my car . it will display all duty cycles like revs, speed, injectors, boost etc etc

 

Hi, I have just had the car checked at the place mentioned earlier. They ran diagnostics on it and there were no problems.

They also installed a Greddy Profec B spec II, which I'm happy with as it's quite a simple piece of kit. (Thanks for the advice on the avc-r bighead but they have more features than I need).

The Electronic boost controller was set up on their rolling road for low and high boost settings. All in all, the fuel cut off problem has been eradicated and the check engine light has finally stopped blinking under hard acceleration.

They relieved me of a few pennies but at least now the car runs as it should!

 

job done then , glad yr sorted m8