1.9tdi PD105 no power, low fuel pressure

I’m having strange low power issue which I’m trying to figure out. Hopefully you guys could help me on this. Car is 2005 VW Touran (which is based on Golf MK5), whith 1.9tdi PD105 engine. Engine code is BKC.
Symptoms are:

• Car has very low low end power. Power starts to kick in at only around 2300rpm.
• There are no fault codes.
• Things get worse when engine fully warms up.
• Engine has some power while it is half-warm, but as soon as engine reaches 90 degrees Celsius things become real bad. Idle fuel consumption goes up from 0.5l/h to 0.7l/h (in hot days when using AC it goes up even to 1-1,1 l/h and I also have to rev engine up before starting to drive, otherwise it would cut out).
• With warm engine there is very noticeable lag (1-2 seconds) when pressing accelerator pedal. And it’s impossible to floor it when warm because engine starts to buck severely. Basically you have to keep gas pedal no more than half pressed to avoid this happening.

In the mean time:

• Engine starts OK, both hot and cold.
• Fuel consumption is OK, maybe slightly higher than normal, but nothing to be concerned about.

I did tandem pump pressure test which showed that fuel pressure is not nearly reaching specified values. So this is obviously the reason for low power, but I would really like to find out what’s causing this.
Following vw service manual I replaced tandem pump with brand new Bosch unit, but it didn’t solve the problem. Next thing vw service manual suggest is changing injector o rings, but I'm really not so sure that this could be the reason...
Fuel filter also has been changed recently.

Any suggestion what else to check/replace? In tank pump (lift pump)?
Any help appreciated.

nin2 said:

Car has very low low end power. Power starts to kick in at only around 2300rpm.

• There are no fault codes.

In the mean time:

• Engine starts OK, both hot and cold.
• Fuel consumption is OK
• .

Click to expand...

Bringing you to the top. I've been having an issue for quite some time now which no one has been able to figure out. Complete lack of low end power until 2000 or so rpm's

You have been focusing on fuel, but I bet you may have a turbo deficiency. Are all your intercooler ducts seated and not leaking (I would not know that configuration). is your boost going up along with demand? you should have 2 atm or more boost from 1500-2300 rpm while under acceleration. There is a thread on a zip-tie mod which assists the lower end opening, without affecting the high end operation. only my suggestion.

How is the torsion (cam timing)? Too much advancement will kill the low end.

Is the car smoking?

Thanks for advices,
Torsion value is mostly 0, under sight load it changes to -0.5.
Car is not smoking.
I have actually done lots of tests to eliminate other possible causes including boost leak test.
I'm pretty confident that symptoms that I'm having are related to low/fluctuating fuel pressure. Pressure gauge readings @ tandem pump pressure port were somewhere around 1.5-2bar at idle.
Question is what could be causing this...
Air in fuel lines?
Defective lift pump? Although i have checked lift pump as well by disconnecting fuel line after fuel filter and pouring fuel in bucket. Lift pump pumped ~1.3L in 20 seconds and that seems to be good result.
What else - maybe damaged head?

any other ideas? suggestions?

For my 1.9L BRM engine the tandem pump is tested at 4000RPM for an output of 7.5bar, or 109 psi. Hope this helps..

nin2 said:

Thanks for advises,
Torsion value is mostly 0, under sight load it changes to -0.5.
Car is not smoking.
I have actually done lots of tests to eliminate other possible causes including boost leak test.
I'm pretty confident that symptoms that I'm having are related to low/fluctuating fuel pressure. Pressure gauge readings @ tandem pump pressure port were somewhere around 1.5-2bar at idle.
Question is what could be causing this...
Air in fuel lines?
Defective lift pump? Although i have checked lift pump as well by disconnecting fuel line after fuel filter and pouring fuel in bucket. Lift pump pumped ~1.3L in 20 seconds and that seems to be good result.
What else - maybe damaged head?

Click to expand...

you should be testing it at 1500 rpm not idle, around 3.5bar min.

My bad, I checked cam timing couple days ago and it was actually reading -2.0 and not 0. I guess this has changed after toothed belt replacement that was done last December (but didn't change my cars behavior). Previous time I checked group 004 was before belt job and torsion value was reading then 0.. Strange.

Well, actually there is one more thing (only I couldn't figure out how it could be related to my low power issue, therefore didn't post it previously) - my cars exhaust smells really really bad, but I cannot find reason for this smell. Diesel fumes are also coming into cabin. Sometimes I even have to turn off engine at traffic lights. I'm pretty sure that i'ts not exhaust leak because power is there while engine has not warmed up and there is also no soot around turbine.

Could bad exhaust smell and low power/strange hesitation be related to incorrect cam timing? Maybe my toothed had jumped a tooth or two before timing belt replacement?

Turbo or egr issue, a sticky vnt mechanism can cause the low bottom end power but also any slight leak from the egr is going to take energy away from spooling the turbo up and leak exhaust gases which will get into the cab.

I'm with Bob the farmer, maybe worth focusing elsewhere rather than just the fuel system

I agree, fuel starvation might have been only one of the issues and its quite possible that it has already been solved by replacing tandem pump. I think I'll redo tandem pump test just to be sure.

p.s. Turbo has already been replaced and EGR has been deleted with no change in symptoms so I think we can cross these two out of list as well :-/
p.p.s. Vacuum selenoid, fuel temperature sensor also have been replaced without any luck. And MAF as well.

Did you solve this problem?

Nop! Problem is still there, so if anyone has ideas what else to do or check please share them here.

Found this article (http://karmakanix.com/knowledgebase/tdi-repair-database/tdi-fuel-filter-frequent-changes/) about fueling restrictions on tdi engines and it says:

“If we suspect a problem because you lost power, were towed in, or we see debris or goo inside the old filter, we will want to do some appropriate testing.”

What can possibly be damaged by being towed in?

Forget that site.

Do a test for in-tank fuel pump (pressure and flow test).
VW repair manual should show the pressure specs which I believe is somewhere abou 0.5 bar.
Maybe you have already removed the in-tank fuel pump and checked/cleaned it?

Next thing I would do some logging (and graphing) for those:
-boost pressure, specified vs actual
-MAF values, specified vs actual at full throttle in 3rd gear.

Sorry waking up a old topic but in driving myself crazy with the same problem, caddy 2009 pd105 got exacly the same symptoms, changed so far 4 turbos vacuum lines, ecu, lift pump, injectors, even got to the point i changed the engine, takes 3 secounds to get full boost dont matter the rpm, changed everything mechanical in the van trying to find this issue till do the to try the part im using in the van on my golf mk5 that drives perfect even with the engine i had in the van.
Now if i force to go higher rpm the engine shakes with lack of fuel, changed the lift pump for a brand new Bosch pump and the idle its slightly better but still drives bad, anyone had this issue or got anymore ideas where shall i look for more testing

Hi I have the same issue, did anyone resolve the issue ?

nin2 said:

I’m having strange low power issue which I’m trying to figure out. Hopefully you guys could help me on this. Car is 2005 VW Touran (which is based on Golf MK5), whith 1.9tdi PD105 engine. Engine code is BKC.
Symptoms are:

• Car has very low low end power. Power starts to kick in at only around 2300rpm.
• There are no fault codes.
• Things get worse when engine fully warms up.
• Engine has some power while it is half-warm, but as soon as engine reaches 90 degrees Celsius things become real bad. Idle fuel consumption goes up from 0.5l/h to 0.7l/h (in hot days when using AC it goes up even to 1-1,1 l/h and I also have to rev engine up before starting to drive, otherwise it would cut out).
• With warm engine there is very noticeable lag (1-2 seconds) when pressing accelerator pedal. And it’s impossible to floor it when warm because engine starts to buck severely. Basically you have to keep gas pedal no more than half pressed to avoid this happening.

In the mean time:

• Engine starts OK, both hot and cold.
• Fuel consumption is OK, maybe slightly higher than normal, but nothing to be concerned about.

I did tandem pump pressure test which showed that fuel pressure is not nearly reaching specified values. So this is obviously the reason for low power, but I would really like to find out what’s causing this.
Following vw service manual I replaced tandem pump with brand new Bosch unit, but it didn’t solve the problem. Next thing vw service manual suggest is changing injector o rings, but I'm really not so sure that this could be the reason...
Fuel filter also has been changed recently.

Any suggestion what else to check/replace? In tank pump (lift pump)?
Any help appreciated.

Click to expand...

did you sort this out ?

I have had same symptoms for awhile, pd105 , cant find the issue, i got turbo boost but slow power in low area, my sisters same car same engine but hers is stock and does not have this issue..
I have New vnt rod, egr deleted, maf deleted, leak tested vacumlines, boostpipes, intercooler. Tried different tuning settings, Still same, seems like it fludds before it "takes". I have boost from 1000rpm so thats not the issue, if i lower fuel afr it does the same but just takes longer.
Has any figured this out?

So I made this account just because I’m dealing with the same issue except for in a bmw. And I figured I’d try to help some of you guys out a little. Idk if this is def your case but I believe it’s mine. My cats are bad. Destroyed. And completely clogged up. And that’s what’s causing my issue I believe. Just figured I’d try to give you guys another place to look.