turbo problem

[brad4816]

i have a 2000 model zd30 di when i hook up the vacum line to the turbo the shaft raises as expected about 20 seconds later the engine seems to miss or surge up and down unplug the vacum hose and it goes away. i have never seen anything like this before and think there has to be a problem with the turbo. the actuator shaft does not move when this happens but moves normally when engine is reved. turbo and vacum lines are standard. if any one has had a problem like this would be greatly apreciated thank you

[Bidja]

Have a bit on today, but does sound like vacum related. You say that:


20 seconds later the engine seems to miss or surge up and down unplug the vacum hose and it goes away

Would suggest to hook up the eng vac port (stand pipe) direct to the actuator diaphram (to bypass solenoid), let it idle and see if the problem solenoid related.

You can slightly rev motor with no load and it will not over boost. With DI and as you may not have a boost gauge, driving it under load is not advisable in case of over boost.

Do one thing at a time.

Is you turbo actuator rod lock nut secure (eg: cannot rotate knurled rod adjuster)? Important do not change rod length or stop screw set position.

What mods have been done to motor?

[mudski]

Any issues when driving it? Can you rev the motor when its missing? Do you have a boost gauge installed? Any manual boost controllers used?

[brad4816]

Have a bit on today, but does sound like vacum related. You say that:



Would suggest to hook up the eng vac port (stand pipe) direct to the actuator diaphram (to bypass solenoid), let it idle and see if the problem solenoid related.

You can slightly rev motor with no load and it will not over boost. With DI and as you may not have a boost gauge, driving it under load is not advisable in case of over boost.

Do one thing at a time.

Is you turbo actuator rod lock nut secure (eg: cannot rotate knurled rod adjuster)? Important do not change rod length or stop screw set position.

What mods have been done to motor? thanks for the advice will check tomorrow. engine is stock reconditioned motor and pump has after market inter cooler, catch can and boost gauge.

[brad4816]

Any issues when driving it? Can you rev the motor when its missing? Do you have a boost gauge installed? Any manual boost controllers used? can rev engine no problems but can feel miss under load. I do have a boost gauge. No after market boost control. Makes boost normally just has this problem when vacum is present goes away immediately when vacum is removed. No up down movement in actuator either when this is happening or in the intake/egr flaps either. Thanks for your time.

[mudski]

can rev engine no problems but can feel miss under load. I do have a boost gauge. No after market boost control. Makes boost normally just has this problem when vacum is present goes away immediately when vacum is removed. No up down movement in actuator either when this is happening or in the intake/egr flaps either. Thanks for your time.

How about driving it? Try removing the vac pipe to the turbo and rev the engine forthe same time as it would normally bring on this issue. Just revving the motor whilst the car is not moving the turbo will be barely working. Driving it is a different story as the motor is under load. I doubt its a turbo issue. Could be just a slightly block fuel filter.

[4bye4]

G'day mate and welcome to the forum.

[Bidja]

Brad, have you tried hooking vac port from eng direct to actuator diaphragm and going for a drive? If so how did boost/pwr respond compared to using VNT controlled solenoid? Caution do not boost above nom 15psi for safety.

Did this on my CRD, bypass the manual boost control and discovered that there was a vac leak between damper and Tillix valve. Understand you have factory boost control, but by isolating your boost control sys you can check for possible vac leaks, poor solenoid operation etc (observe performance variation). Also discovered that my turbo actuator rod length was set incorrectly and required a lot of trial and error to get it right. The turbo and actuator was an upgrade (H/Flow) that was off another engine and could have also been messed around with incorrectly (please do not adjust your rod length at this stage).