Stopped boosting at 5k...

[davegttph1]

Hmm, coming into work this morning I put my foot down, the car was fully up to temp and pulled out of a junction with pace 1st gear as soon as it hit 5k it sort of stopped boosting and the car backed off.... so obviously I backed off... thought it was strange, put my foot down again and as it was boosting it was very irractic, sort of jumpy and intermittently trying to boost. now Ive had this before sometimes..... not all the time mind just every now and then, stuttering on boost but mainly only when the 2nd turbo is boosting...

Anyone have any ideas of a starting point? Im guessing something simple like a vacuum leak. Not had chance to look under the bonnet yet though...

[Martiny]

If you have the standard intake, I would start with checking the big pipes that go from the airbox to the turbo intakes. These pipes, when old,  can collapse when hot, and when under suction.

[davegttph1]

I have an HKS (I think) intake... they do look old and dirty though... still worth checking the pipes? as theyre plasticy.... ?

[nikp]

Definately, worth checking: there are a few companies on ebay that do a hard pipe kit to replace the plastic ones you have remaining. This is what i have done. Doesn\'t cost too much either.

[davegttph1]

ok cool thanks it does only do it whilst hot actually... OK I\'ll go have a nosey on ebay now then

[Mave]

I had a similar symptom with a dodgy HT lead

[davegttph1]

them HT leads look a right pain in the ar$e to change, the plugs wasnt too bad once I had the right tools but the HT leads, I cant even see where they dissapear too

[Initial-D]

Lol what were they thinking when they did the engine layouts!!

[Mave]

them HT leads look a right pain in the ar$e to change, the plugs wasnt too bad once I had the right tools but the HT leads, I cant even see where they dissapear too

I didn\'t need to change the whole lead, it just wasn\'t attached to the plugs properly  :cool

[MattR]

Are you sorted??  i Had an identical problem on my t88 supra... was on dyno and woul dhit 5.5k or .8 bar and bang nothing,... no boost and cut theeng.. now i first thought it was something in the map..but its turned out to be a ****ed boost controller.. as with it all umplugged it will boost and rev out..although iv now found a ****ed w.g..

[davegttph1]

Dunno it must have been a one off because Ive not had a problem since, given it a bootful plenty of times and its been perfect....