Good evening all,
just had a manual boost controller fitted properly at last by my son-in-law as it was installed totally wrong by local garage. problem is i took car out for a blast tonight and as soon as i floored her it was as though i had hit a brick wall but as soon as i let off the gas she was fine
. the car is a my97 uk turbo. mods are mushroom filter, decat straight through exhaust. any ideas anyone what the problem might be.

 

what have you got the boost set to on the mbc, as if you have it higher than your fuel cut it will over boost and cut hence the reson it will feel like you are hitting a brick wall

 

I'm no expert but sounds like your car is overboosting and the brickwall was the fuel cut to prevent damage to your car.

What make boost controller did you fit?
What did you set the boost at?

Just fitted one (turbosmart) to my 02 wrx last weekend and no problems.

must have posted at same time lol

 

As said, the MBC is prob wound open far too much and the ECU has saved you from a blow-up by cutting boost, as it will be boosting beyond the MAP sensor's limit.

Do you have a boost gauge? If so, check what's happening... but only do this the once! Chances are the needle will fly past 1.2+bar/17+psi, just before hitting the boost cut!

If so, then wind the MBC right back in so it's totally shut. This should now only allow the wastegate actuator's raw boost level which is only c.0.5bar/7psi.

Bit by tiny bit open the MBC out a tad and go for a drive each time, using full boost. What you eventually want to end up with is about +0.2bar/3psi more than the OEM boost. I think a MY97 UK Turbo (208bhp) is 0.7bar/10psi, therefore you want your boost gauge to hold around 0.9bar/13psi... and NO MORE!

 

as said above,also check your maf sencor isnt knackered because you have an induction kit fitted,it cuts power out at about 75-80mph

 

if you have a boost gauge what is it reading at? and what way did you set up the boost controller? check ur maf and check your boost solenoid aswell just to be sure give it good clean with brake cleaner, also it sounds like its just over boosting as above because it is not tuned/remapped for its mods and requires more fuel and the ecu cant handle this so needs to be tuned for them mods have you upgraded the fuel pump at anytime, best bet is to turn boost down on the MBC and keep it at that until you can get it remapped to handle its mods

 

Joz, winding the MBC in will surely compress the spring and increase boost will it not?? By opening/un-winding the MBC you will slacked the spring pressure allowing the valve to open at a lower pressure. Thats how the Dawes works!!

I had a cheaper type fitted and the spring kept getting stuck on the internal threads, so no matter how far you un-screwed it it wouldn't reduce boost, just a thought!

 

Seems to me like the fuel cut defender working as others have said because of overboosting. I'd take Joz8968's advice. In other word's go back to standard boost, and adjust it abit at a time until you can reach full boost without overboosting & hitting the fuel cut.

 

Just for your info GMB, A fuel cut defender is a device that prevents fuel cut mate, imho not a safe device/mod. What the op is experiencing is the ECU 'cutting' as it should when to much boost is present, a FCD would prevent this safty mechanism coming in.

 

Oh sorry, I thought they worked like one of those 90's bleed valves. I forgot that it worked by using a spring... thus obviously requiring more boost to overcome it when it's tightened up (and not slackened).

Sorry if I misled the OP.

 

Yes your right my mistake...wrong wording (FCD)
You see I had a similar problem when I bought my car. It was hitting what felt like a "brick wall" and when I investigated this I found a nasty £5 manual boost adjuster was to blame because it was inproperly set up and causing an over-boost on my car wish in turn caused the ECU safety mechanism 'thingy' mabob "brick wall effect". I tryed adjusting it but decided it was safer to bin the nasty bit of rubbish in order to stop the problem, plus I intend to get an electronic boost adjuster in the future when it's all mapped to work in harmony.
Must be all that lack of sleep the last two nights

 

thanks for all your terrific advice guys, im not sure what controller it is bought it at jap fest for £14 not even sure if its plumbed in properly this is my first scooby ( at 47 years young ) just a bit worried about driving it. if anyone has diagram of how it should be plumbed in that would be great. all i can tell you is it has x3 outlets apart from that im stumped. look forward to your comments.

keith

 

3 ports could mean that it is indeed a bleed vave type boost controller, I think.

Are you sure you're not mistaking it for the OEM MY93-96 3-port boost control solenoid and its 3 vac hoses?!

Any chance of posting a pic up of it (and the pipes going to/from it) as it is at the moment in your bay?...

 

Does it look like this???

Boost Solenoid Plumbing