Td5 Sluggish - Lack of Power - Nanocom readings

Shifty1962 said:

Are you sure the wastegate is not stuck open? Even a little bit open will limit boost. Disconnect the modulator and make sure the wastegate flap moves very easily. Have you got a bicycle tyre pump? If so you can confirm the wastegate actuator is working by applying pressure to the inlet pipe. Dont use a full size compressor as it is easy to over pressure the thing and the actuators are not available separately from the turbo AFAIK.

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Langers said:

The wastegate is definitely free, with the actuator rod disconnected I can move the arm with one finger. Will check the actuator today if I can figure out how to attach a pump.

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Shifty1962 said:

You need less than 20 psi to confirm actuator operation.
The wastegate should be completely closed until boost builds and then it should open smoothly with increasing pressure.
Max boost on a standard TD5 is about 1bar or 15psi.
The stock Garret turbo is capable of boost pressures in excess of 30psi.
However the ECU will switch to limp mode at just over 1bar to protect your engine from overboost should the wastegate jam or the actuator fail.

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sierrafery said:

I hate to contradict you but on a well working engine the max boost on a standard Td5 should be 1.1bar for Defender and 1.3 for D2(due to the wastegate modulator), 1bar is the max limited boost in case of AAP sensor failure and the ECU will go in overboost protection at aprox 1.4 bar(240 MAP) cos actually it works based on the MAP reading but as tyhe AAP is generally around 100KPa(1bar) we can extract the boost from the MAP reading.

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Langers said:

Adjusting the wastegate to shorten it doesn't give an increase in boost pressure. How can I tell if this is because the turbo is fooked or because it's not getting enough gasses through it to spin it up?

Would it be an incredibly bad idea to completely disconnect the pipe to the wastegate actuator and see if the turbo is capable of producing enough boost to knock the ECU into limp mode?

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Langers said:

Adjusting the wastegate to shorten it doesn't give an increase in boost pressure. How can I tell if this is because the turbo is fooked or because it's not getting enough gasses through it to spin it up?

Would it be an incredibly bad idea to completely disconnect the pipe to the wastegate actuator and see if the turbo is capable of producing enough boost to knock the ECU into limp mode?

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Shifty1962 said:

How much did you shorten it by? Did you test it under load?
You could disconnect the actuator pipe and try as in theory the ECU will protect the engine if/when boost gets too high. It would also prove the turbo is boosting properly. Have you got a boost gauge fitted as that is the easiest way to see what is going on? Have you taken the turbo inlet pipe off and seen the compressor vanes spinning with the engine running? Does it speed up noticably when the engine is revved? It will not spin as fast as when under load so will not produce much boost. Dont put your fingers or anything else in there lol.

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Bennehboy said:

Bit of a wildcard suggestion here... it shouldn't have a CAT in the downpipe since it's a 99, but some muppet could have fitted the wrong type during its lifetime, worth checking because the CAT can block up giving symptoms almost exactly like you have.

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Langers said:

Tried this today - turbo seems healthy as it made enough boost to knock the ECU into limp mode with the actuator pipe off. Pretty sure the turbo is working ok - even if its bearings are a bit worn. Put it back to standard afterwards (including wastegate modulator) and am getting between 210-220 kPA max boost on Nanocom. Should be enough.



Good suggestion, but there is no cat fitted to it. I disconnected the exhaust before the mid-silencer today to see if that was blocked, but no change except for lots of noise.

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