Surging Revs at about 90 up steep hill

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Originally Posted by OffTrack

Not the turbo hoses, the three small diameter hoses that connect to the modulator, from the metal pipe between turbo and intercooler, and from the modulator to the actuator can on the turbo.

If these split you get the same symptoms as a failed modulator.

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OK thanks. Guess this is my weekend task then! Appreciate the clarification.

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This only happens on steep hills at about 90 and just below 3000 RPM. The
revs seem to surge up and down - TD5/auto.

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I guess My interpretation of your post is that your speed stayed the same but engine revs increased and decreased. If this is the case is is TC lockup as that is the most common thing that would cause differences in revs Vs road speed.
If on the other hand the car is physically speeding up and slowing down then the above answers will be more likely.
Is the car speeding up and slowing down or are the engine revs fluctuating and the car speed staying the same?
Regards Philip A

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Originally Posted by PhilipA

I guess My interpretation of your post is that your speed stayed the same but engine revs increased and decreased. If this is the case is is TC lockup as that is the most common thing that would cause differences in revs Vs road speed.
If on the other hand the car is physically speeding up and slowing down then the above answers will be more likely.
Is the car speeding up and slowing down or are the engine revs fluctuating and the car speed staying the same?
Regards Philip A

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Hi Phillip

You're correct in your interpretation. The speed was staying the same.

I guess a bit of maintenance and checking these items isn't going to hurt anyway!

Thanks
Jake

did you work out what it was, my td5 has started surging around 3k rpm and its not the maf, as had that tried... i will look into the turbo modulator though.

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Originally Posted by haydent

did you work out what it was, my td5 has started surging around 3k rpm and its not the maf, as had that tried... i will look into the turbo modulator though.

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Not yet - I haven't been up any hills to test it yet!

i think i may have fixed mine. i tried gripping the modulater rod, but couldnt get a good enough grip, so took the turbo heat shield off. now i could grip the pivot easily.

I found it not going all the way (assuming its meant to go as far as possible).

With a bit of added rotational force it made a little bang, and now goes all the way...

Took it for a drive and it did the little surge the first time i put it in a position to do it, but never again.

Hope i didnt break anything in the vacuum diaphragm, and that its meant to move all the way ?

Wondering if there's any test i can do or get done to check that mechanism is still working ?

i spoke too soon, it didnt fix it, i just didnt test it on the right hill...

but i think i have fixed it by bypassing the modulator, as it hasnt done it even though i tested it on some nice big hills.

Quote:

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Originally Posted by haydent

i think i may have fixed mine. i tried gripping the modulater rod, but couldnt get a good enough grip, so took the turbo heat shield off. now i could grip the pivot easily.

I found it not going all the way (assuming its meant to go as far as possible).

With a bit of added rotational force it made a little bang, and now goes all the way...

Took it for a drive and it did the little surge the first time i put it in a position to do it, but never again.

Hope i didnt break anything in the vacuum diaphragm, and that its meant to move all the way ?

Wondering if there's any test i can do or get done to check that mechanism is still working ?

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