1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

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EnJay
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Joined: 22 Apr 2020, 11:24

1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by EnJay »

Hi guys,

I have an issue with my Ducato motorhome, which has a PSA 1.9TD (Code:DHX which is a XUD9) which has been fittet in Xantias:

The car is running out of power at ~100km/h, before it was possible to get up to 120km/h.
It feels like there is a soft Rev limiter around 3000rpm as I can´t get it over that in 5th or 4th gear. It feels like it wants to rev higher and then bogs down again.

It does pull quite okay below 3000rpm considering the weight and power and I haven´t noticed a lot of smoke.
I also pulled the boost pin out to have a look if the pin down inside is stuck, but its running freely.
EGR is fittet. Is there an easy way to check if it is stuck (seems to be a nightmare to get it out)?

Has anybody of you experience with those old lumps and has seen something similar?

wheeler
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Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by wheeler »

Basics first, Is the fuel filter good? Have you checked the throttle cable is adjusted correctly? have someone hold the pedal to the floor then check you cant push the lever on the injection pump any further.
The EGR valves on this engine don't normally cause any problems (apart from clogging the whole air intake system like all EGR valves) but the only way to check it properly is to remove it & physically check it's moving freely.

EnJay
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Joined: 22 Apr 2020, 11:24

Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by EnJay »

Thanks wheeler!

Fuel filter will be changed as I already planned it - so it could be potentially just the filter?
OK, so I will put the EGR down on the list to check.

Do the injectors clog up a lot in these engines? The last owner mentioned he often used a cleaning additive to clean them

moizeau
Donor 2020
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Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by moizeau »

I don't know which injection pump you have but how does it accelerate if you floor it? If as before ignore the rest. There is a diaphragm on the pump that injects extra fuel when it is needed. It's connected to the plenum chamber with a rubber pipe. It's vacuum operated. Two things can go wrong, the pipe can split or the diaphragm can puncture. As said, if it accelerates as normal ignore this. The other thing is, with an assistant, if you press the pedal down fully does the lever on the pump move all the way to the stop?

EnJay
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Joined: 22 Apr 2020, 11:24

Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by EnJay »

I have the Bosch pump.
I would say it accelerates quite well when I floor it - it just seems to run out of power at around 3000rpm.

I already opened toe diaphragm top to inspect the fueling pin.
The diaphragm was like brand new - no puntures visible. The pipe (it was more a hose) seemed fine.
Only thing was that there was oil above the diaphragm. I hope that this accumulated over the 200k kilometres - at least the boost pipe just after where the pipe goes to the pump was not that oily

moizeau
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Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by moizeau »

Take the hose off from the plenum and see if there is a difference. Plug the hose with a small bolt. That will verify the diaphragm.

moizeau
Donor 2020
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Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by moizeau »

Another thing, on the drive, in neutral does it rev beyond 3000rpms? How does it rev if operating the pump directly from the lever, and does it hit the stop when using the pedal?

EnJay
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Joined: 22 Apr 2020, 11:24

Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by EnJay »

Hi,

I drove a small round today:
- It does rev beyond 3000rpm in neutral
- It does rev beyond 3000rpm in 1st gear

I haven´t had the chance to change the filter yet

EnJay
Posts: 6
Joined: 22 Apr 2020, 11:24

Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by EnJay »

Hi guy´s,

I have changed the fuel filter, but honestly hadn´t had the chance to test if its okay now.
I also checked the turbo - not a lot of play there (axial and left/right/up/down) - seems like brand new.

But I also bought the measuring tool for adjust the injection timing (?ist this the right word?). But I can´t find the values für the engine in my workshop manual (it only says look at the plate on the pump?). Does anyone have the right values for the DHX engine for fuel timing? Preferably in mm ;-)

Thanks a lot!

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white exec
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Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by white exec »

A restriction or partial blockage in the exhaust (eg the cat) can cause what you describe.
Try disconnecting the exhaust before the first exhaust box (swing the pipe to one side, and secure with wire) and try revving and driving. Being a turbo diesel, it will be surprisingly quiet, because the turbo smooths out the exhaust pulses. See whether that makes a difference.

EnJay
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Joined: 22 Apr 2020, 11:24

Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by EnJay »

...yeah I think the Problem is solved...

I just wouldn´t beleave, that it would be the easy and first thing I thought of:
It really was just the diesel filter

I changed it and now it runs 130kmph (mind you: its a motorhome) and has no more powerloss.
I´m quite happy that it was that easy.

moizeau
Donor 2020
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Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by moizeau »

Good news, it was always going to be a restriction in or out. 99% of the time it's something simple.

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white exec
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Re: 1.9TD DHX (XUD9) - Powerloss - can´t rev over 3000rpm

Post by white exec »

Yep, strangled at one end or the other.
Glad it's sorted. \:D/