[Closed] 2.0 HDi woes...

So many thing it could be and as your finding you can end up just changing everyother bit till its fixed. Idealy needs to be driven with live data recorded to see whats going on.

Assuming you have done the obvious check of the air filter and pipes for a blockage i would head towards the fuel pump.

Check all vacuum pipes for splits. Check turbo boost pipe for splits opening up when on boost. Check turbo actuator etc. Presuming the 90 hp has a turbo of course. Chris diesel to the forum!

I did find a hole worn through the vaccum pipe to the EGR solenoid where the hose had rubbed on the engine cover. This has been fixed.

I don't think it can be turbo related (yes, it does have a turbo), as the turbo isn't active at these kind of engine speeds.

Have you asked/searched on [url= http://www.frenchcarforum.co.uk/forum/ ]French Car Forum?[/url]

The turbo will be spinning at all engine speeds, so I wouldn't rule it out.

Hi, try driving the car with the air flow metre disconnected, the idea being if the air flow metre is disconnected the Ecu will revert to internal mapping for air and fueling. Also depending on age there is a vacuum control throttle valve on the rear of the engine that can stick on light throttle or low rpm.
I'll have a think or any other issues.
What's the last 8 of the vin no?

Thanks Chris. Vin ends 93263460. I have tried the disconnected MAF sensor, and had no joy. I replaced the MAF as there was a light film of oil inside the old one, and I suspected that that wasn't a good thing. I have also put jubilee clips around both ends of the crankcase breather pipe as there was oily residue escaping at some point and the pipes were not a tight fit.

Slight thread hijack, I replaced the air mass meter on my 2002 2.0 HDI C5. There was a huge improvement in immediate torque and acceleration. Soon after the performance went back to its slow coach mode. It wasn't that I became accustomed to the improvement. When you fit an air mass meter is there any other reprogramming required? I simply switched the old part for the new one.

My mechanic has suggested fitting a tuning box from [url= http://www.tuning-diesels.co.uk/products/ronbox-1/ ]Ronbox[/url], which I wouldn't be averse to if it doesn't bump insurance too high and it has a beneficial effect. I understand it works mainly by boosting fuel rail pressure. Is this a bad thing?

Morning, not looked at the tuning box web site but my feeling is "cheap" chip boxes that mainly just re route the fuel fail pressure and tell the Ecu it's lower than it actually is are a very poor way of increasing power, and generally cause smoking/over fuelling and seen one blown engine, proper remapping is different again but expensive and without being rude it's not a sports car.
Let me have a look today at the known issues and the type of system on the car.
E mail me trout wrestler

Sorry, film of oil inside air mass unit is normal, corrosion around the thing that looks like a Match inside it and on the silver squire plate inside are the things to look for.

Mcmoonter - you have a fault somewhere else on the car. Try getting the fault codes read. Was it a new MAF you fitted?

.

Tuning box is more for economy than power. With my current issues, economy is definiately down, probably as I have to drive faster to overcome the hesitation.

Chrisdiesel - I cannot find your email address. Mine is in my profile.

Cheers,
Charlie

With my current issues, economy is definiately down, probably as I have to drive faster to overcome the hesitation.

this is doubtful. economy is probably down because there is a fault somewhere.

Id be checking none of the turbo hoses have delaminated - as your turbo spools up and creates negative pressure these can squash and cut flow.

Id relook at the vacumn hoses to the EGR - checking carefully the T pieces and round any joins. Id look for perished diaphragms in the EGR but performing a suck/blow test on it and verifying it opens and closes when it should.

Id look for air leaks in the air intake up stream of the MAF sensor

all take into account that its been serviced as it should be as ive had similar feelings from bad fuel filters in my DW8 non turbo engine- feels like a dead spot in the engine between 1500-1750 that it could pull through but then when it reached 70 it struggled to go any further - felt like a dying fuel pump. turned out to be a blocked and partially colapsing fuel filter.....

Mcmoonter - you have a fault somewhere else on the car. Try getting the fault codes read. Was it a new MAF you fitted?

Yes it was a new MAF, Ive tried two now. Pricey at about £80 each.

I've not got a fault code reader. Is there anyone in Fife you could recommend?

now mcmoonter

that is something i might be able to help with.

i dont have an HDI engine but if you can find out what protocol it uses i could post you my code reader - iirc its an OBDII reader i have but ill check tonight.

works with my peugeot van and 107s

OBDII readers are £7 on ebay, they work just fine, software for them is also easily picked up off the net. Then get a list of fault codes and go through them..

i went for the all in one unit - just pings up a code and you refer to the handbook.

how ever - dont follow them blindly as they can point you in all sorts of directions away from the real source

i have that and its paid for its self a few times over.

I've had a boost pressure sensor go on a Passat; there was a hesitation thing going before it became an obvious lack of turbo boost as symptoms got worse.

i dont have an HDI engine but if you can find out what protocol it uses i could post you my code reader - iirc its an OBDII reader i have but ill check tonight.

Where would I find out what engine protocol I have? VIN no?

Further update:

The van went into what I assume is "Limp Mode" on the way home tonight. Massive loss of power which nearly was the end of me when I pulled out onto a roundabout...

I have whipped the blanking plate back out, and although the EML is not on, the van seems to still be in Limp Mode. Is there a simple way to re set this?

Disconnect battery for a bit - 20mins / half an hour should see it bugger off unless it was actually nothing to do with the egr plate.

Maybe an o2 sensor, now that its in limp mode get the codes read.

McMoonter - I'm in Milnathort, and the fella at French Vehicle Services (maybe worth a shot?) in Kinglassie recommended [url= http://www.dmautoelec.com/index.html ]Daryls Auto Electrics[/url] for ECU reprogramming (I want my Cruise Control activated).

I use Stewart and Smart in Milnathort, but this problem with the hesitation has them stumped. EGR was their idea.

Parksie - I don't think there is an Oxygen/lambda sensor on the diesel?

It should have one maybe two.

Cheers Troutwrestler. I will give them a shout.

I had a 2.0 HDi picasso (probably the same engine) and the throttle cable was slack. there is a clip you can take the tension up with. Worth a shot.

Yep, tried the throttle cable tension too.

Just reconnected the battery after half hour disconnection. Still in Limp Mode 🙁

Time to get your codes read. Sounds like it wasnt egr after all

Here's an update: The codes were read on Thursday - the only one being "EGR Fault". The car was then out of Limp Mode, but still had the same issue on light throttle. Suddenly yesterday and today the problem has vanished. It has been much colder. I wonder if it is temp related, or just voodoo?

On that car where is the throttle position sensor? On my 306 with the same engine the electronic throttle position sensor sits right behind the rad/bonnet latch and gathers rain in the back of the connector every time you open the bonnet or go through a puddle.

I had the exact same symptoms with no fault codes (I have all the readers, scopes, you name it, tried different MAFs, removing the MAF entirely, cleaningit, blocking the EGR) and it turned out to be corrosion on the throttle position sensor connector. Removed it, cleaned up the contacts with light emery paper (they didn't look too corroded), lubed up with petroleum jelly and re-connected and it was fine ever after.

On that car where is the throttle position sensor?

I get the low rev stutter on my 407, same 2.0HDi engine. As it's only used for long runs/occasionally I'll live with it until whatever is causing it properly dies, especially as the throttle position sensor (generally acknowledged as the most likely cause) is hidden in the pedal box and a nightmare to get to on mine...

The TPS is mounted on the engine mount stiffener adjacent to the offside wheelarch. I am just going to leave it at the moment while the going is good, but have suspicions about the TPS. Those in the know tell me that the TPS is very reliable, with the ability to self test, but it would explain the symptoms. I have seen a TPS strip'n'rebuild how-to on a 306 forum, so may give that a go.

sounds like a bit like a problem with my audi which turned out to be an intercooler leak

No intercooler on the 2.0Hdi 90ps, only on the 110ps.

A further update...

I have replaced the TPS - no difference. I have been for a diagnostics session with a local diesel injection specialist, but they could find nothing significant wrong (Previously a fault with the clutch switch had shown up, but I don't think the clutch switch does anything as I don't have Cruise Control installed. Also a fault with the cooling fan, but I don't see how this could be relevant). They're opinion is that given that no faults are showing, it is likely to be something mechanical, or maybe an earth fault - I have disconnected and cleaned what I think are the main earth points on the nearside wall of the engine compartment, and I have performed a BSI reset - no effect!

I feel that the surging is getting more frequent, more severe, and occurring across a wider range of RPM - generally under light throttle (right on the cusp of throttle vs overrun) between 1500-2000 RPM.

Am I mad to consider that the timing belt tensioner could be loosening, allowing the belt to flap in these circumstances?

Confused! (and squeaky bummed if it is the timing belt tensioner...)

Get some form if scan tool hooked up to the car. Even Torque on your phone with a decent Bluetooth adaptor should be able to give you live info on lambda and boost pressure etc. You're trying to find a fairly minor sounding driveability fault, so something is probably going slightly wrong intermittently. A decent scan tool can monitor the engine's sensors and give you a good steer as to what's going on. A fault code reader will only pull up problems that are enough to properly upset the car.

And stop changing bits at random and thinking the ECU might have corrupted. It's French, but even then, computers are pretty reliable things. You're far more likely to find a simple mechanical fault like a boost leak of dodgy filter than you are to find that your ECU has gone mad. And if your timing belt was flapping about, it would land on the road pretty sharpish I reckon.

The scan tool is exactly what the diesel specialist hooked up, then we drove around for 45 mins. The car was misbehaving, we could feel it, but the live data was showing nothing erroneous from any of the sensors.

Bluetooth OBD reader shows spiky fuel pressure when fault occurs. I thought that this could be a faulty pressure sensor, pressure regulator, or third piston deactiveator solenoid on the HP fuel pump, but the technician dismissed these saying if they were faulty, a code would be showing.

It might seem like it's minor, but when it's shuddering, my kids heads are rocking backwards and forwards like a scene from Wayne's World.

Just had a quick scan of the thread.

My first guess given the symptoms would be EGR valve, however since blanking that didn't change a thing, that's ruled out.

However without access to live data, everything else is pure guess work. General things I'd be checking would be boost pressure (i.e. is the wastegate actuator/control solenoid working), and a general check of the fuel system (i.e. injector balance and fuel pressure).

My gut feeling would actually be a fuel system issue, given the specific RPM range it happens. IIRC the injectors on a diesel of that era reduce the number of injection phases at 1500RPM. An injector balance check via live data, or a leak off test may show up something, but not always.
There is also the classic check of the fuel filter housing for any metal bits lying in the bottom, which is a potential sign of something breaking up in the fuel system.

Injector balance has shown (from memory) 92%, 95%, 105%, 108%. Technician's opinion was that this wasn't unreasonable on a 130,000 miler, and that injectors were unlikely to be the issue.

A simple 'suck' test on the EGR solenoid, and I can hear it click upon release. The feed into the inlet has soot in it, but is nowhere near clogged, and the gas comes through no worried. Blanking it caused limp mode. I think it is most likely a fuelling issue. Fuel pump is of course driven by the timing belt.

Maybe it is a partially blocked Cat?

Bluetooth OBD reader shows spiky fuel pressure when fault occurs. I thought that this could be a faulty pressure sensor, pressure regulator, or third piston deactiveator solenoid on the HP fuel pump, but the technician dismissed these saying if they were faulty, a code would be showing

Find a new technician.
Not having a fault stored, just means something hasn't exceeded a pre-programmed limit, not that that specific item isn't the cause of the problem.
Spikey fuel pressure could easily be the problem, it's just a case of finding out the cause. Given the longetivity of the problem i.e. it's not failed completely, it's obviously not something overly critical that's failing.
Again live data is your friend. When the fault is happening, what is the fuel pressure regulator PWM? Surging i.e. pressure goes high, PWM drops with no related drop in pressure, on that reading would indicate the valve sticking. Again checking how the 3rd piston cut-off is reacting would help point you in the right direction. If there is no corresponding response in any of the actuators/sensors, then it could be an actual mechanical pump fault, as the 3rd piston cut-out does operate around that speed, however I would expect that to either work or not work (if it did fail to cut-off, I'd expect over pressure faults, and if it failed cut-off, I'd expect poor response at low speed due to low fuel pressure).
Everything else I can think of would normallu cause issues under high load, during starting, or at low speed.