Low power and limp mode nightmare

[RKH735]

Hi I’m new to the forum but hopefully someone can point me in the right direction. Mk8 2.2 17 seat minibus camper conversion, but nothing changed mechanically. 50k with decent history.
Started going into limp mode after 40 miles or so, no lights or prior warning, just cut out but would restart and work fine for a while, then do it again soemwhere between 40 and 100 miles later. Got worse over a few months and started to do it immediately after restarting. Been into garage who initially diagnosed faulty turbo actuator, with fault codes P2562-71 and 2563-00.
Swapped actuator for new and re built turbo. Fault came back after 30-40 miles, back in and new boost sensor fitted. Still got fault but now at around 100 miles+, would clear and come back about 100 miles further on, always in 6th gear and at 50-60mph.
Then it started to run rough just before it went into limp mode - noisier engine, loss of power and occasional “ticking” noise when lifting off the throttle. Would go into limp mode and restart ok, but still rough until it sat switched off for a while. Fuel economy became much worse when running rough. It then started to do it in 1st gear under load, such as a steep hill, and very occasionally on moderate throttle and lower speeds and gears. Van always starts ok but is really rough, noisy and hesitant on startup. No apparent smoke when driving. It sometimes hesitates and sometimes “coughs” but there isn’t any pattern to it. Occasionally got code for EGR being stuck open as well as above faults so taken for further investigation…
Ended up with new DPF, cat and vaporiser plus fuel filter. EGR all working ok. Full check over showed everything (injectors etc) working to correct parameters. Garage drove van back to back with another, only issue they could find was that on same van, at same speeds and route the other one showed much more variance on the turbo position - one was at 70%, whereas mine was around 30% at the same point.
So, back to turbo garage. Checked over again including MAF and intake MAP sensor compared to another identical van and all matched.
Turbo is free and seems fine.
The only issue is with the actuator - on the other van an example measurement - the “commanded boost actuator control bank” showed as 79%, and the “variable nozzle turbo position” was 79%, showing the commanded position was being achieved. On my van at the same throttle position the commanded was 0%, but the turbo position was 79%.
So the turbo is apparently working as it should, but the van doesn’t seem to be telling it to? It would them seem to make sense that the limp mode is actually caused by these measurements being vastly different.
This has left 2 garages stumped and me bankrupt with no clue where to go from here - is anyone able to assist?

[jack26]

Hello, wondered if you got this problem resolved?

We have similar vehicle and conversion with misfire issue that has been getting worse It seems to always be when uder load around 1600 - 1800 RPM in second gear.

In our case I am trying to diagnose fault and been using ForScan which has shown that then the misfires occur the EGR valve is moving open although its comand from PCM does not agree. This seems similar to your issue with Turbo variable vane where PCM does not appear to require a change from0% but Turbo actual is 70 odd?

Wondered if there is any correlation and could be due to sensor values being incorrect so PCM goes into som sort of default mapping that no longer sends correct actual demand/position data to the ODB11 port?

My post is at:- viewtopic.php?f=64&t=224753

[RKH735]

Sadly not yet sorted. Been into a further garage who ran a full diagnostic using Forscan but their conclusion was an issue with the replacement turbo actuator. Couldn’t get the van to talk to it nor would it do a relearn. Everything else checked out ok including injector, MAF, manifold pressure sensor and EGR. Going for new from Ford turbo and actuator next week so I’ll keep you posted. Had a nightmare trip away again with it cutting out at both low and high speeds, which was nice, plus misfiring when cold on a light throttle opening - if driven hard it seemed to go away. No idea why at this stage so we’ll see how the turbo goes and take it from there.

[jack26]

Thanks for reply,

Looked at the info in ForScan for turbo and 0% is turbo vanes fully open with anything else being towards closed so assume 75% for example would be 3/4 closed on vanes. Looking at my turbo values most of the time they seem to be in the 70 odd % range.

Perhaps as you say the Ford fit would probably be a possible solution if the re-learn on current one did not resolve your issue. Always difficult to determine which supplier Ford used but when I worked for DANA there always had to be at least 2 but more usually 3 different suppliers such as Delphi, Pierburg, Hella etc depending on component for any application.

[Silverfoxbuilds]

Hey guys, I was wondering if you had any luck with this this sounds very very similar to mine. I have a long story of this basically going on for at least 18 months where the vehicle was drivable but always known something was up with it.

My MPG has gradually getting worse and worse and worse. 13mpg!!!

Over Easter week the, van threw six engine management lights. Seemed to be constantly in limp mode.
On the return journey, the van would go into limp mode when in upper gears lower Reese and this would be rectified by a cycle of the key. I finally mostly get at home and in limp mode and it showed an actuator position fault.


I’ve come home and over the last month or so replaced the turbo after an actuator Fault and And a few discussions with fellow transit minibus owners having identical faults and the turbo being the fix. then subsequently gone through almost The entire turbo system replacing sensors and the like.

To date I have changed
the turbo(Hybrid Falcon With Hella actuator)
Change the turbo again for replacement turbo from Falcon as we thought it might have been a second faulty actuator
MAP
MAF
EGR peirburg
Intercooler
Boost pipe where required
Re-map
Limiter removed
Throttle plate cleaned
New breather hose to turbo pipe

Pressure tested and will very slowly fall from 17psi
Smoked tested and no visible leaks.

I am plagued by a P0299 under boost fault code. The van doesn’t seem to want to build boost until around 2000 rpm.

It’s been to a ford specialist And it’s been too ford Neither of which could find Any fault. Annoyingly Ford couldn’t even put it into limp mode, even though I gave him a detailed description of exactly what is required to do so.

Any help would be greatly appreciated. I am losing hair Money and the will to live with this thing.


Thanks in advance