Technical Intermittent loss of acceleration on gear change

[Eirediver]

Hi all, hope you can help with a problem I am having on my motorhome.

2010 Fiat Ducato motorhome (Left hand drive) 2198cc with engine code 1736407 (4HV) which I believe is the 100 Multijet / 2.2 HDi engine (I am not 100% on that, but that's the best I could figure out online)

Vehicle takes off fine in 1st gear, but as soon as you engage 2nd gear the acceleration completely drops, no lights on the dash show and the engine is barely accelerating, if you keep the accelerator fully depressed it eventually climbs speed slowly and then once up to speed you engage 3rd gear and your acceleration is back to normal. On other occasions the same can happen in 3rd gear instead of 2nd gear (but appears to be less severe of a loss of power in 3rd gear, that may be due to the fact that the vehicle is at a higher speed than when going from 1st to 2nd). The whole vehicle almost feels like it brakes when this happens and everyone gets shunted forward, it is an obvious and sudden loss of power.

Engine runs fine other than this, no other issues.

Fault is intermittent, only happens sometimes after a cold start, once it happens once it runs fine after that and may or may not happen the next day, at the next cold start, being a motorhome it isnt used every day and is parked up (outdoors) for long periods of time. I suspect the fault happens more often after a wet night, but that may also be just by chance.

Mechanic has removed DPF and EGR, but fault continued a few months later, I haven't got to get it checked reliably for any fault codes as previous mechanic cleared the codes and said to come back to him once problem happened again but it didn't happen for several months and he's not really interested now, I need to get to the bottom of it now as I can't trust that I won't breakdown while abroad and end up stranded.

I've searched the forum and read several similar problems pointing towards throttle body and electrics and possibly a clutch sensor (recent thread) but other threads are for different engines and not exactly the same symptoms, so opened my own thread to look for some advice, really appreciate any pointers here.

Andy

 

[the green vanper]

Hahaha, those mechanics who think that DPFs and EGRs are all evil

Any errors on MultiEcuScan or AlfaOBD? Each case can be different. First thing is to check what the engine tells us.

 

[Eirediver]

I know, they were hell bent on the DPF and EGR being the cause, at least they have gotten it off their chest now

I don't have anyone near with multiECUscan but will try with AlfaOBD or will look at getting one or the other, if not I'll find someone to do the scan and see what it comes up with.

 

[Eirediver]

Ok so I managed to read the faults with AlfaOBD and a cheap OBD diagnostic interface. The codes showing are:

P0401
U0426
P0010
P1056

Attached is the screenshots of the faults on the app

 

[theoneandonly]

P0010​

A Camshaft Position Actuator Circuit (Bank1)​

P0401​

Exhaust Gas Recirculation Flow Insufficient Detected​

U0426​

Immobilizer,​

The rule of P1056 Fiat Ducato code when it comes to emissions-related vehicle repair is that any modification that changes the vehicle from a certified configuration to a non-certified configuration is considered tampering: this applies to both vehicle owners and repair facilities and is, therefore, a Federal offense. Replacing a catalyst with a straight pipe is one traditional example of P1056. Likewise, overriding the OBD P1056 DTC For Fiat Ducato system through the use of high-tech defeat devices or non-certified computer chips, for example, would also be considered tampering. The OBD system may, however, be repaired back to its original certified configuration with certified performance chips or appropriate aftermarket parts.
this was from

P1056 Fiat Ducato DTC Code | EngineDTC.com

P1056 Fiat Ducato DTC code meaning and find error in engine that is causing P1056 DTC check engine light.P1056 DTC For Fiat Ducato fault code repair process steps and advices.

enginedtc.com

The rest was specific to BMWs. Very little info on this code.
My 3 pence worth
need confirming by someone who intimately knows older models.
the Camshaft sensor on later models is only involved in starting does it have significance here?
the egr is controled by a vaccum solenoid device so good pipework is vital to every thing working ok. check for leaks and blockages. Check that the end of pipe at egr end has not been deliberately blocked (previous mechanic)
Remove egr and clean and check for smooth closure/opening.

Unfortunately unlike later models with electrically driven valves you cant read live data and see the valve moving.

 

[the green vanper]

P0401​

Exhaust Gas Recirculation Flow Insufficient Detected​

the egr is controled by a vaccum solenoid device so good pipework is vital to every thing working ok. check for leaks and blockages. Check that the end of pipe at egr end has not been deliberately blocked (previous mechanic)
Remove egr and clean and check for smooth closure/opening.

From the first post I've understood that the mechanic removed the EGR and DPF from the vehicle. Without reinstalling it later. But I can be mistaken. In such cases they generally block the flow to the no longer existing valve. And that makes the system crazy...

I've heard of emulators, but I'm not a diesel fan (as the fumes are carcinogenic and soot is blocking the alveoli), so I'm not an expert. I also think that today's engines are too complicated and overloaded with electronics to fool with them. A team of engineers equipped with expensive computers invented how it should work. So cannot be sure if some mechanic can know better...

 

[Eirediver]

Thanks for the replies, really appreciate your help with this.

In relation to the work the previous mechanic did on the DPF and EGR, I'll have to confirm what exactly he did and figure out if he reinstalled it later, However that was done AFTER this problem started happening, and was done as an attempt to remedy the problem, not sure if that helps at all with finding a solution to this problem, as I dont feel that it caused this problem, may have worsened it or caused another problem as suggested but may not be the root cause of the problem

 

[Eirediver]

Im still at a loss with this one and not happy to trust it on another trip untill I have it sorted.

I think I might have to get the work reversed that the previous mechanic did of DPF / EGR and see if problem does continue, I hope it isn't just a red herring in the whole problem.

A good bit of reading in this forum has suggest a similar issue with other engines in relation to the throttle and / or the throttle electrics? Do you think this could be a possibility here or is it relevent to my engine?

Thanks again for all the help

 

[Communicator]

Im still at a loss with this one and not happy to trust it on another trip untill I have it sorted.

I think I might have to get the work reversed that the previous mechanic did of DPF / EGR and see if problem does continue, I hope it isn't just a red herring in the whole problem.

A good bit of reading in this forum has suggest a similar issue with other engines in relation to the throttle and / or the throttle electrics? Do you think this could be a possibility here or is it relevent to my engine?

Thanks again for all the help

Hi,
As you have mentioned the possibility of red herrings, may I introduce another possibility, which is probably another red herring.

I would make it clear that I am thinking outside of the box, but on another thread I have been discussing a 2.8jtd with similar symptoms. EGR was optional on the 2.8jtd and not a common fitting. The current suggestion is that a sticking brake pedal switch may be the cause of intermittent loss of power. However it could also be a turbo/boost problem.

Here is a link to the other thread.

 

[Eirediver]

Thanks again for the replies all.

Unfortunately after 2 trips over the last few weeks the problem has got worse, with it now happening in every gear, all of the time, so I only barely managed to get it home from the last trip.

I don't know if it is a good thing or a bad thing that the problem is constant now, on one hand it means I can get to the bottom of it finally as it is no longer intermittent and I don't have to worry about when it will happen again, but on the other hand it is now broken down and I am fearful this is just going to be a money pit replacing parts to get to a solution.

In case it changes anything, here is the problem as it currently stands:

No lights on the dash, no black smoke and van idles fine. I take off in first gear and the van has no power and is only barely driving, slowly will build speed, very slowly and then can change to second and power dumps again and is only crawling along. I found if I revved the engine during gear changes as I was coming off the clutch (I know this wasn't a good thing to be doing), I didn't immediately loose power when engine was engaged in gear so allowed me to build speed, although it was still very sluggish and had minimal power.
Also as I was driving, it would eventually get up to speed and if I kept my foot on the accelerator, even only slightly accelerating, I wouldn't loose power, but as soon as I let go of the accelerator and tried to then accelerate again I would loose power, to get power back (albeit reduced power) I would take the foot off the accelerator for a second until you could feel the accelerator disengage (I hope that makes sense) and then push the accelerator again and sometimes you would get a little bit of acceleration to keep you going. That's how I got it home.

Faults are all the same as before, with no new ones (I didn't clear the ones from the last time though)

Where would you all start with it now?

Again, thanks so much for any direction or help you can offer

 

[AndyRKett]

and is, therefore, a Federal offense.

quick point…. We don’t live in a federation there is no “federal offence” in the uk same in Ireland no “federal offences” there either

To the OP I’d look at the turbo and waste gate, it sounds to me like it’s struggling to build boost, when you’re changing gear there is no boost pressure so it’s like trying to accelerate without the help of a turbo

 

[theoneandonly]

quick point…. We don’t live in a federation there is no “federal offence” in the uk same in Ireland no “federal offences” there either

To the OP I’d look at the turbo and waste gate, it sounds to me like it’s struggling to build boost, when you’re changing gear there is no boost pressure so it’s like trying to accelerate without the help of a turbo

It was a direct quote from the yank website quoted after it. It in my eyes means there is no actual error or fault but a modification has been made that may be illegal somewhere.