first of all apologies for my lack of technical terms...bit of a noob

so I fitted a boost guage the other day and since then I am only getting about +.5 bar boost on my '99 GT(noticeably less boost). The o2 sensor was also replaced during the week which I think may have caused another problem. Anyway first things first. When I was fitting the boost guage I used the spare connector on the manifold(that was blanked off with a rubber cap) but I accidently snapped the T piece(plastic was rotten) that had 3 pipes(about 5-6mm each)connected to each other. 1 pipe goes to what I think is the actuator on the turbo(round device connected to the turbo).second pipe connects directly to the inlet on the turbo(close to where the bottom pipe from the intercooler connects to the turbo).The third pipe connects to an electrical connector attached to the left wing. I used the spare T piece I got with my auto gauges to replace the broken 1 but it is physically bigger and the internal diameter holes of this T piece seem smaller. Also the pipes do not fit as well but I have then clamped on so I think they are ok.I also had to cut back the old pipe going the the electrical block as it had split. I also had to completely replace the pipe going the the actuator with some spare pipe that came with the boost gauge. the spare pipe I used does not seem to be as heat resistant or as strong as the orignal. My question is could this be causing my low boost issue? Any advice on what I could do to sort as trip to mr subaru are becomming expensive.

Since the o2 sensor was replaced(prior to the boost gauge) I have noticed some hesitation from the motor especially when boost just kicking in. Could the o2 sensor cause this hesitation?

Thanks

 

The pipework you mention from actuator to turbo to inner wing is the boost control pipework. The electrical device is the boost solenoid. In one of the pipes there should be a brass restrictor (turbo side I think). If you have changed this pipe for one without a restrictor then you will get less boost.

I would advise checking to see if you have the restrictor in place and replacing it if you removed it. If that doesn't work then check for leaks. It may be that you need to replace all the pipework and have a correctly sized t-piece, if some of the pipes are perished then chances are they will all have started to go bad. I'd get this sorted out and see how the car is before anything else.

 

sorted...it was the restrictor...
I noticed there waas a restrictor in the t piece as well.when i took out the restrictor on the orignal pipe to the turbo I was boosting @ +1.5 bar...what a buzz!!
Put the restrictor back in the orignal pipe and removed the restrictor from the t piece and now she's back to normal...happy days

thanks for the advice

 

now got some more problems or I think so at least...
The pipe going to the boost controller split so I decided just to go to Mr Subaru and get them to sort it once and for all. They reconnected as I had it and used some nifty clamps so the pipes are good and tight. The head subaru mechanic took the car for a test drive with me in the passenger seat and now it appears to be overboosting (to me anyway). The boost gauge now goes up to about 1.1-1.2 bar for a few secs and then goes back to 1 and stays there. Everytime he put the boot down or changed gear the same thing would happen. The other day before the pipe split the boost was reading just under 1 bar and stayed there....never went over that.Just wondering if this is normal as I really dont want to hurt my turbo. If this isnt normal what do you think could be causing this?

thanks

 

cold weather.

 

i understand the colder the weather the better the boost but would that cause the boost to go from 1 to 1.2 to 1 bar in the space of a few seconds and keep doing it? The boost just isnt consistant.I would have thought that if the colder weather was effecting the boost it would be constant...apologies if I'm being dumb here

 

Its peaking at 1.2 bar then tailing off, sounds normal to me ????

 

Is this GT, the same as a standard uk turbo car? If it is , the boost is more than it should be unless it has a ppp ecu fitted. Also, did the mechanic fit the standard 1.2mm uk re-strictor or the P1 0.9mm re-strictor? If he has fitted the P1 type it will boost more than the uk type.

 

I thought MY99 GT was the same as MY99 AWD UK boosting at 0.9 bar as standard? If the hole in the restrictor is to small plus the cold weather,then there we go FUEL CUT

 

when i got home from subaru I decided the replace the pipe with the original restrictor still in it. I put the original restrictor in my newly fitted pipe that goes onto the inlet of the turbo and its still the same. I even put the restrictor in the opposite way in the pipe but still exactly the same.I put my foot down and my boost registers 1.2 then back down to 1 and then back up to 1.2 and then back to 1 bar and keeps doing it. this is most noticeable in 4th and 5th gear. I can see any leaks on any of the pipes.

It is a standard spec uk GT....no performace mods...

Would a reset of the ECU help does anyone think?

what amazes me is it was fine(0.9 to 1.0 bar everytime when foot to the floor) until the pipe to the boost controller split the other day...but that has been fixed and is securley attached to the t piece.

what is fuel cut?

any other ideas ?

 

would a boost controller sort it?

 

fuel cut is a violent engine cut......