Technical Engine revs falling down a hole !

[Road Sailor]

Hi, we have a 2001 Ducato motorhome manual gears. The engine has developed a fault, going up through 1st and 2nd gear is fine, speed is building nicely, however when changing up to 3rd, 4th the engine revs plummet, not good when you have traffic behind you or going up hill. However when the revs increase again the van goes really well in top gear. We have changed the fuel filter, had the turbo checked, had the ECU sent away and checked, had the throttle pedal changed. Annoyingly the Fiat dealership garages do not have the software to plug into the socket so we have no idea what error codes there may be. We feel it must be something really simple . Has anyone experienced this or any ideas of what the problem could be? Thanks
Cathy

 

[bugsymike]

What engine 1.9, 2.8 ?
Assuming it is turbo intercooled, first thing I would check is all the turbo pipes and intercooler for leaks.
If nothing obvious , it may still be worth garage putting a smoke test on it to show if any leaks from turbo to inlet manifold.
Is there any black smoke when power down as often that is an indicator of low boost pressure.

 

[Road Sailor]

Thank you, husband can help me with answers now 2.8jtd.

 

[Communicator]

Given the year of the vehicle, and that it has an ECU, the engine can be either 2.0jtd, 2.3jtd, or 2.8jtd. The engine capacity should be shown in the V5C........

 

[Road Sailor]

Hi it’s a 2.8jtd fuel filter changed

 

[Road Sailor]

Given the year of the vehicle, and that it has an ECU, the engine can be either 2.0jtd, 2.3jtd, or 2.8jtd. The engine capacity should be shown in the V5C........

It’s a 2.8jtd

 

[Communicator]

Given that the problem is associated with gear changing, I have developed a niggling thought that it could be a sticking clutch pedal switch (sensor). However I am not sure whether this would match the symptoms, or go the other way. Unfortunately I do not have time to check on this until this evening.

 

[Communicator]

A quick addition in haste....

 

[bugsymike]

Ah! 2.8, the best engine in my view.
What about any other symptoms when driving?
Even things that may seem irrelevant may help diagnosis.

 

[Anthony489]

Hi

I don't quite understand what's happening from your description. Do you mean the revs drop right down to below normal idle speed when you dip the clutch to change gear ? Do you mean that power/acceleration at low-ish RPM is poor immediately after changing up a gear, and with the clutch re-engaged ?

A lack of torque ("pulling power") is more noticable in higher gears, and could have many causes but low boost pressure or under-fuelling are possibilities.

 

[Communicator]

A quick addition in haste....

Please note that the information attached to post #8 above was taken from eLearn for the x244. The earlier x230 model may differ in detail, as adaptions were made to accept the common rail engines, e,g. replacing the 2.8idTD with the 2.8jtd.

 

[Road Sailor]

Hi

I don't quite understand what's happening from your description. Do you mean the revs drop right down to below normal idle speed when you dip the clutch to change gear ? Do you mean that power/acceleration at low-ish RPM is poor immediately after changing up a gear, and with the clutch re-engaged ?

A lack of torque ("pulling power") is more noticable in higher gears, and could have many causes but low boost pressure or under-fuelling are possibilities.

Hi, thanks , yes your second suggestion, the revs drop down to about 1000 and gradually creeps up again.

 

[Road Sailor]

Ah! 2.8, the best engine in my view.
What about any other symptoms when driving?
Even things that may seem irrelevant may help diagnosis.

There are no other symptoms, it starts on the key and runs smoothly, happy to idle and sounds normal and healthy.

 

[Road Sailor]

Hi, we have a 2001 Ducato motorhome manual gears. The engine has developed a fault, going up through 1st and 2nd gear is fine, speed is building nicely, however when changing up to 3rd, 4th the engine revs plummet, not good when you have traffic behind you or going up hill. However when the revs increase again the van goes really well in top gear. We have changed the fuel filter, had the turbo checked, had the ECU sent away and checked, had the throttle pedal changed. Annoyingly the Fiat dealership garages do not have the software to plug into the socket so we have no idea what error codes there may be. We feel it must be something really simple . Has anyone experienced this or any ideas of what the problem could be? Thanks
Cathy

I would like to add that it has an aftermarket John Gold cruise control fitted. One of the garages have assured me that they disconnected it, because I thought it may be causing the issue…

 

[bugsymike]

There are no other symptoms, it starts on the key and runs smoothly, happy to idle and sounds normal and healthy.

So no visible black smoke when lose of power?

 

[varesecrazy]

Hi, thanks , yes your second suggestion, the revs drop down to about 1000 and gradually creeps up again.

Hi Cathy, and welcome

1000 rpm is it's natural idlespeed,
"tick over" will be @900..

So its Not stumbling at idle, but has very little acceleration in upper gears.

Have you owned it long, covered many miles?


Garages cannot communicate..
I take it it has 3 Pin diagnostics, that is OBD "1", 1ST generation

(OBD2 has been around 20 years, so you can see why the old version is now uncommon,)

However, you could buy the cables yourself for relatively little cost

 

[Road Sailor]

Hi Cathy, and welcome

1000 rpm is it's natural idlespeed,
"tick over" will be @900..

So its Not stumbling at idle, but has very little acceleration in upper gears.

Have you owned it long, covered many miles?


Garages cannot communicate..
I take it it has 3 Pin diagnostics, that is OBD "1", 1ST generation

(OBD2 has been around 20 years, so you can see why the old version is now uncommon,)

However, you could buy the cables yourself for relatively little cost

Thank you It’s a Benimar Motorhome.
We bought it just before Covid needing cosmetic repairs to the bodywork. We stupidly did not realise that because of the weight 3.8 my husband (diabetic insulin) is no longer able to drive vehicles above 3.5. So we continued to complete the bodywork repairs and last summer it was ready to go for its MOT, we got someone to drive it for us to the garage, it drove brilliantly, no problems at all, I was behind in the BMW and struggled to keep up on the main road !! After the MOT was passed, a new battery was put in the aftermarket cruise control, the van was washed and put up for sale. A lovely couple bought the van from us. Shortly after purchase the issue with the revs dropping and temporary loss of power when changing up gears. We feel obliged to do the right thing and get the motorhome working properly for them. We have purchased the adapter for the OBD reader, no faults are showing, but maybe we don’t have the correct software to read it. It has been to two garages who have sent the ECU away for checking and checked the turbo . It has done about 65,000 miles and has had cambelt and water pump changed just prior us purchasing. It’s a 2001 so just prior to the changes in 2002.

 

[bugsymike]

Thank you It’s a Benimar Motorhome.
We bought it just before Covid needing cosmetic repairs to the bodywork. We stupidly did not realise that because of the weight 3.8 my husband (diabetic insulin) is no longer able to drive vehicles above 3.5. So we continued to complete the bodywork repairs and last summer it was ready to go for its MOT, we got someone to drive it for us to the garage, it drove brilliantly, no problems at all, I was behind in the BMW and struggled to keep up on the main road !! After the MOT was passed, a new battery was put in the aftermarket cruise control, the van was washed and put up for sale. A lovely couple bought the van from us. Shortly after purchase the issue with the revs dropping and temporary loss of power when changing up gears. We feel obliged to do the right thing and get the motorhome working properly for them. We have purchased the adapter for the OBD reader, no faults are showing, but maybe we don’t have the correct software to read it. It has been to two garages who have sent the ECU away for checking and checked the turbo . It has done about 65,000 miles and has had cambelt and water pump changed just prior us purchasing. It’s a 2001 so just prior to the changes in 2002.

I know nothing much about your cruise control system , however if fault occurred after battery replaced in cruise control, perhaps try disconnecting that battery. I appreciate you have mentioned that garage has disconnected cruise control from the system , however it could still be affecting things due to a defective wire or something.
On a slightly different note, was the original cruise control battery faulty or disconnected by the previous seller, as from the sound of it you are very honourable people, but not all are.

 

[varesecrazy]

Thank you It’s a Benimar Motorhome.

We have purchased the adapter for the OBD reader, no faults are showing, but maybe we don’t have the correct software to read it. It has been to two garages who have sent the ECU away for checking and checked the turbo . It has done about 65,000 miles and has had cambelt and water pump changed just prior us purchasing. It’s a 2001 so just prior to the changes in 2002.

There Is specialist FIAT software that many of us on here use,

It's called MultiECUScan, and runs on a Windows Laptop

Where are you based, I am near the M4

But the forum has a register of users, if you are hundreds of miles away

 

[Road Sailor]

There Is specialist FIAT software that many of us on here use,

It's called MultiECUScan, and runs on a Windows Laptop

Where are you based, I am near the M4

But the forum has a register of users, if you are hundreds of miles away

Thanks Mike, we are right over in Norfolk!