chrisray

hi all, changed all my boost hoses on my 99 turbo the other day. found a great differance in boost (1.1 bar instead of 0.8). but today when driving home, the power died suddenly and then came back just as quick (frightend the life out of me, thought i broke my new car).i have no clue on what im doing so im going to get the car tested. where is the best place in south wales to get this done. also is it normal for the boost to drop off a little at the top end of revs, or is it something i've done (not putting hoses on tidy). sorry to post so much its new car and im still not used to it. thanks chris

c_maguire

Don't take it anywhere just yet unless you have a fat wallet. I have read your other post and 1.1 bar (16PSI) is the correct max boost for a PPP '99 car, however what you describe (sudden loss of power as if you've turned the car off with the key and then turned it back on again when giving it some beans) sounds like fuel cut is happening. This occurs when the boost exceeds a preset level for a certain length of time and is there to protect the engine from damage (I think it's about 19PSI on your car). When boost builds quickly it will overshoot the target level of 16PSI before settling back (this is normal) and this is why fuel cut is set at 19PSI ish and not 17PSI.
You should try 2 things. First off clean your boost solenoid, because if it's contaminated it can result in overboosting and then fuel cut. Do a search on here for how to do it. Secondly, try a restrictor pill with a slightly larger hole in it. You say you changed the pipe and pill, but it's not always as simple as " '99 car, PPP, TD04 turbo, that'll be a 0.9mm pill Sir".
One last thing. Is the PPP unmolested, or has someone also replaced the downpipe, which will give a faster turbo spool-up and possibly result in overboosting?
Kevin

mike799

as above,sounds like fuel cut,did you refit the restrictor pill after changing the pipework to boost solinoid?if you didn't that could be your problem

chrisUK300

iTrader: (10)

would not fitting the restrictor pill result in a lower boost figure or am i talking out of my @rse

chrisray

hi all, i checked the pipes again today all seems fine. i also cleaned the boost solenoid. but one thing i noticed, i think i have an after market down pipe . so im putting the over boosting down to that. would i have to get a remap done or is there another way to stop it? i am very poor . thanks for all the help, in my opinion this is the most helpful club i have ever joined .

on to a different subject, once i finish changing all my hoses, i think i will have some samco sport pipe left (for boost pipes). if someone would like it, they could have it (FREE). but i'll start a new post, when that time comes.

thanks chris

c_maguire

With the pill missing, the boost pressure is acting directly on the wastegate which starts to open at around 6-7PSI, thereby preventing a boost pressure any higher than that. So you are correct.
Kevin

c_maguire

A remap with a competent mapper is a bit of a winner on any of these cars, even a standard car will run smoother and return better fuel economy, but it's gonna cost upwards of £600 and with PPP your car is already tweeked, albeit with a 'one size fits all' map.
I would still try a restrictor with a slightly bigger hole to see if this stops your problem, Subaru supply them in 0.5, 0.8, 1.0, 1.2 and 1.5mm. You can drill them yourself if you need an intermediate size (I think Maplins sell tiny drill bits).
If the problem still occurs it may be that the boost solenoid or wastegate actuator are faulty (although very unlikely to be the actuator). A restrictor pill at £2 is a lot cheaper than a £140 boost solenoid so try the pill. If the car is overboosting then it will be running slightly lean at this point, increasing the hole size in the pill will reduce the boost so it is a 'no risk, easy on the pocket' test.
Kevin