Turbo pressure on 16V turbo series 2

[bjarke]

Hi all,

The issue is that I dont feel that the car has same performance as for a year ago.

I have then measured the pressure at the inlet manifold, with a precise electronic device, that I borred from my company.

At "normal" conditions the pressure maximum gets to 0.85 bar. The overboost never shows a sign from the panel, and I cannot see a raise in bar.

When I remove the 2 valves that are connected to the wastegate pressure, the maximum pressure is only 0.5 bar...

Q:
Is the 2 valves for overboost, and is the wastegate then misadjusted, or am I missing something..

Best regards
Bjarke

[David Hanson]

Overboost is triggered by a microswitch attached to the throttle body, by the plenum chamber. It is secured by bolts that have been known to come loose. If the plate the switch is mounted on becomes loose then the switch does not operate (it only ever operates at full throttle). The valve attached to the waste gate is a solenoid actuated valve that bypasses the waste gate actuater in over-boost conditions. .85bar sounds about right for normal boost conditions - not sure what you can expect in over-boost.

[Vince Bhachu]

Hello Folks

My mate has a problem on his 1992 Turbo 16v too, at 4500 rpm the car tends to misfire and judder, the Turbo wants to kick in, but it just hesitates, he is still drving the car, but needs some advice, any info anyone ?


Vince

[David Hanson]

I had something similar with one of my 8v turbos - car would hesitate, judder etc just as boost was coming in. Turned out there was an air leak (split hose) in the high pressure side of the inlet (downwind of the turbo) As the turbo boosted some air would be lost through the split causing the motor to run very rich as the Air Flow meter had detected all this air going into the motor the engine management computers adjust the fuel accordingly. Another symptom was very dark exhaust smoke, ie almost black fumes from the exhaust.

[Chris]

If you have solved the problem by now good for you. If not I will dig out my info from years back (very long story & expensive heartache).

Regards Chris