..Bought a rev 1 turbo from a mate, only mods are K+N induction, s/s decat exhaust, BOV.
No form of aftermarket boost control. He had the car dyno'd at 230 bhp at the fly. The car boosted smoothly up to the '+' mark on the boost gauge. After he had it a while the indicated boost dropped to around 7 psi, although still boosting smoothly to this level. Car run on optimax, there are no ecu error codes, and several ecu resets were performed.Checked the hoses, no leaks, suspected the T-VSV was limiting boost.
Disconnected the hose that runs from the actuator to the T-VSV to 'simulate' the T-VSV opening and the car boosted all the way to '+'. Then checked the pin from the ecu that triggers the T-VSV and found that it was at +12v, indicating the ECU reckons the engine is knocking and won't allow T-VSV to let the car boost over 7 psi ( pin goes to ground to activate T-VSV, btw). The car always gets optimax, it is running rich enough (soot on exhausts, a little black smoke on boost), it doesn't overheat on boost, and there is no audible pinking at any time. I decided to check the ignition timing in case it was too far advanced and causing pinking. Dizzy was already set fully-anticlockwise (retarded as far as it will go?), but with strobe triggering off no1 HT lead and TE1 and E1 shorted on the diagnostic port I can see no timing mark on the crank pulley. The 'writing' on the alternator belt is 'moving' when I fire the strobe at it, surely this should be stationary? I even put a tippex mark on the crank pulley and tried the strobe again but nothing!Regardless of the position of the dizzy I see no timing mark under the strobe.
Firstly, is the timing somehow so far out of whack that I can't adjust it by turning the dizzy? The car runs fine apart from the boost limitation, remember. Secondly, is it possible the car isn't in fact detonating and there is some ECU problem with the T-VSV trigger signal? Is it possible for the knock sensor to give a spurious 'knock' signal yet not produce an ECU error code?Thanks in advance!
ST
