Tonk Posted April 24, 2007 Share Posted April 24, 2007 i've got a boost problem on a 200 tdi defender engine which is sending me round the bend. the way the piping is plumbed is the boosted fuel takes pressure straight from the turbo, wastegate actuator and boost gauge runs from the intake manifold. it gets to 11 psi boost then no more, i shortened the actuator rod to up the boost but it still stayed at 11 psi, the actuator ended up spring bound but still no more than 11 psi, is i disconnected the tube onto the actuator and plugged it then the turbo instantly produced 20 psi with no problems. so i thought that the actuator might have a leak in it so i changed it, the same thing happens with the next actuator, so to prove the actutor isn't leaking i disconnected the rod to the wastegate and held the gate shut with a jubilee clip, boost went straight up to 20 psi again. so to summarize, both actuators dont leak, both are spring bound so shouldn't allow the wastegate to open, the turbo will produce over 20 psi, i've changed all actuting tubes and tubes to gauges and tried 2 boost gauges which read the same, but i'm still only getting 11 psi boost when its all connected up anyone suggest anything obscure that i haven't tried? TIA Mark. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted April 24, 2007 Share Posted April 24, 2007 Not an expert by any means, but it seems from you've said that the engine (or rather the pump) is restricting the turbo. Have you tweaked the inj pump at all? Les. Quote Link to comment Share on other sites More sharing options...
Tonk Posted April 24, 2007 Author Share Posted April 24, 2007 the pump is tweaked up, star wheel turned downwards, diaphram turned clockwise, overall rear screw upped to, seems strange it will pull the boost if i disconnect summat? Quote Link to comment Share on other sites More sharing options...
Jon White Posted April 24, 2007 Share Posted April 24, 2007 Does it have a boost modulator valve anywhere in it?? Sorry - I know stuff all about tdi's so no idea if they have on or not? Jon Quote Link to comment Share on other sites More sharing options...
Tonk Posted April 24, 2007 Author Share Posted April 24, 2007 hmmmmm, a wot? Quote Link to comment Share on other sites More sharing options...
white90 Posted April 25, 2007 Share Posted April 25, 2007 Mark am I correct in reading this you are seeing 11psi boost on the gauge (connected to the manifold) and no more no matter what you do to the wastegate? but connect the gauge direct to the turbo(no wastegate connected) and you see 20psi on the gauge. if so, I had a similar problem where a jubilee clip in one of the rubber hoses had failed letting the pressurised air out you could hear a faint whistle whilst driving. new clips sorted it, also can you try the wastegate with differing pressures to check when it is opening? I used a spare tyre let down till it wouldn't open then checked the pressure in the tyre I have 18psi before the W/G opens now boost gauge(calibrated) confirms this. Quote Link to comment Share on other sites More sharing options...
Tonk Posted April 25, 2007 Author Share Posted April 25, 2007 i can see 20 psi measured from the manifold is i disconnect the wastegate, either the tube that operates the actuator or the bar that goes to the gate (gate held shut with a jubilee clip). all hoses are samco and all clips look good, i'll have a check though. Quote Link to comment Share on other sites More sharing options...
white90 Posted April 25, 2007 Share Posted April 25, 2007 can you get a regulated supply onto the W/G to see when it is opening. Quote Link to comment Share on other sites More sharing options...
Tonk Posted April 25, 2007 Author Share Posted April 25, 2007 i think that will be my next course of action Quote Link to comment Share on other sites More sharing options...
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