Loss Of Power D-4D - A Little Advice Needed

[phitchen]

Hello everyone.

Hopefully you can collectively offer a little advice to a newbie.

Right, we seem to have gained the dreaded "loss of power" fault with our 54 plate Verso diesel. It's a T3 7 seat model witk the 2.0 litre engine.

A bit of background.

We put whatever diesel in it we can find when it needs some, but our local stations are either Shell, texaco and tescos, so these are what it generally gets. TBH, Tesco's is probably used more than the others just out of convenience.

We've had the car almost 12 months, and the fault has been happening on and off far about the last 3 months or so. It all started after the car was left on the drive for a week while we went on holiday for a week during April. Until this point it had been flawless, but upon getting back, this loss of power prob started to occur.

Typcially it only happens at over 50mph, and typically it happens when you try to accellerate after the car has been on overrrun. So for example on the motorway, cruising along (either with or without cruise control on), lift off to wait for an over taking space, space comes, depress the throttle and nothing happens....so gear down to 4th, floor the throttle, still nothing, so gear down to third, floor it again, after a pause and a few coughs and splutters, and a big cloud of black clag out the back, off it goes. However at it's worst it returns immediately as soon as you go back to 4th or 5th gears. At it's best it may not happen again for the whole journey.

The problem seems to be getting progressively worse, occuring more and more frequently.

Now, I've had a bit of a trawl on here at likely problems, and to pick these off:

1. I've checked and replaced the fuel filter for the goo/gum issue from 'cheap' or bio fuel, and the filter was as clean as a whistle (but non genuine, so I replaced it anyway)

2. Subsequently it's been to the dealer for a service (as it was due 70k miles) and they found no fault codes, and typically couldn't get the fault to occur.

3. Suction control valve

4. Injectors

5. Fuel pump

Now, as a chartered engineer, I consider myself pretty good at fault recognition, and pretty handy with a set of spanners :) And to address 3,4,5, above, then I would expect (although I have no specific experience of high pressure common rail diesel pumps) if there was a problem with a pump it would not be intermittant, it would likely be entirely repeatable and more consistant, and also progressively worsen, so it does not really fit the progression of my particular fault.

Injectors - no idea about their typical fault modes so have not ruled these out, but my gut feeling is that it is not these, it just doesn't seem to quite fit right.

SCV's - now for me these seem the most likely issue, and would be the one I would do next, as valves if damaged or worn can stick intermittantly, and in an entirely unrepeatable or unpredictable way. This to me seems entirely more consistent with the evolution of the problem we have.

However, I have no idea where to find them, what they look like or how easy there are to replace - can anyone point me in the right direction?

Does anyone know if it is a DIY job, or special tools type thing ?

I see (from info on here) that they appear to cost about £120 for a pair, plus fitting, are these a dealer only part, and will they know what a suction control valve is if I ask for one.

Advice appreciated.

Thanks

Paul

[dervdave]

will they know what a suction control valve is if I ask for one.

Its the first I`ve heard of one Paul

Intermittent problems like these are a real pain because the reason could be just so many things.

I would try a good diesel additive/cleaner and a full tank of V-Power to see if it helps before changing parts just in case there is some gunge somewhere in the system but I always try the easy/simple things first.

:)

[phitchen]

will they know what a suction control valve is if I ask for one.

Its the first I`ve heard of one Paul

Intermittent problems like these are a real pain because the reason could be just so many things.

I would try a good diesel additive/cleaner and a full tank of V-Power to see if it helps before changing parts just in case there is some gunge somewhere in the system but I always try the easy/simple things first.

:)

Already tried that and it didn't make any difference :( I tried it in conjunction with changing the fuel filter, in case it was a fuel quality/blockage type of issue.

The SCV's come up on here if you search for D4D power loss, or diesel power loss as I think I used.

[Cyker]

When it happens to me, I wait until the tank is almost empty, fill it up with V-Power and thrash it down the motorway until it feels better

However, it seems that cleaning out the EGR valve may also help

If you almost always drive at 2000rpm or less, it's very likely that the EGR or injectors or something are becoming clogged with soot.

Once you get it sorted, you could try the new Shell FuelSave diesel to see if that mitigates the problem (It will be more expensive than supermarket fuel tho'; Over here it's 4p more :( ).

Ideally, I'd fix it on mine by running it on nothing but V-Power, but at over 12p/L more than my usual diesel I don't think I could stomach it

(I really miss when fuel was < £1/L!! :( )

The power loss is quite a common problem with people that do mostly city driving with the D4D (Except with those joyriding Corolla owners ) but in most cases it does seem the EGR valve is the culprit.

If you want to burn it off, you need to run the engine really hot for an extended period, not just a short burst.

Cleaning the EGR valve directly is probably better for the engine, and there is a post on here somewhere where someone cleaned out their Yaris' EGR (I can't find it as usual, but maybe someone can link to it...?). You sound more competent than me with mechanical stuff so it might be worth trying (Doesn't sound too hard, just really f'ing messy! )

[phitchen]

It gets regular motorway running so gets plenty of chance to get hot.

I'll have a look at the EGR valve though.

[Bod & Hammie]

Hi phitchen,

Look in the last thread about my experience.

Although Mr T put new injectors in I am convinced it was just the EGR valve as the engine has only done 22k miles.

Yours WILL be caked as they all are unles they are cleaned 2 or 3 times a year.

Look at thread http://www.toyotaownersclub.com/forums/index.php?showtopic=97232

These are the picture refered to in the above post.

Hope this helps.

Bod

[phitchen]

Yeah I'll check the EGR, but other peoples decsriptions of their problems prior to cleaning the EGR seem to indicate hesitation, with ours, you can pin the throttle, and hold it there as long as you like and nothing happens (I mean I've held it there for 30 seconds plus with no change), the car continues at the same rate, or continues to slow down (if the load is increasing - like on a hill)

If it's in cruise, it often drops out of cruise as the speed gets too far below the set point, so it gives up....

[Bod & Hammie]

Didn't I read somewhere on here that there is a control box or sensor somewhere under the throttle pedal that controls the throttle, cruise control and also is linked in to the brake lights (for cruise disengagement).

May be this is not reading the throttle position so not accelerating or it could be another sensor or ecu problem.

Just thinking outloud really but they are possibilities.

Bod.

[phitchen]

All good ideas, but I would have thought these would trigger an ECU fault code, the dealer said there were none present and none stored.

Anyway, I'll look into that as well.

So at the weekend, I did:

1. Injectors - checked resistances across terminals and all in spec.

2. Control valve on fuel pump (the SCV?) and this was in spec across the terminals.

3. Vacuum control valve (for boost control) and again in spec across terminals.

4. Took the EGR off and had a look.

Firstly, the EGR on this car is not a 15 minute job as per the Yaris link above, it's a real b**ch to get at. You can just do it with some degree of awkwardness by removing the airbox (to allow you to get at one of the coolant hoses, and the the fasteners that hold it in place, and you have to take the vacuum control valve off to get to the other coolant hose clip to release it.

Anyway, EGR had a light and even coating of carbon, and moved freely, no sticking. So don't think there is anything adrift there, although I didn't get the petrol out and thoroughly scrub it, I just put it back, as I don't think my symptoms match those of people with EGR probs, I don't hava a hesitation as such, it's just a complete failure to respond to the accellerator.

Anyway, just a quick update, will keep you posted.

Amnymore suggestions, please keep them coming.

Might have to get it in to a specialist, There is one just up the road in Hucknall, called TRD, can't remember the full name (and yes the irony of their use of those intiails is not lost on me:) )

[phitchen]

Didn't I read somewhere on here that there is a control box or sensor somewhere under the throttle pedal that controls the throttle, cruise control and also is linked in to the brake lights (for cruise disengagement).

May be this is not reading the throttle position so not accelerating or it could be another sensor or ecu problem.

Just thinking outloud really but they are possibilities.

Bod.

Ah, and another thing, that I think may rule this out.

When it is has exhibited a failure, and you have geared down to 3rd, and it is then responding and accellerating, if you flat shift from 3rd to 4th gear without even lifting the throttle from it's pinned to the floor position, it can then still go straight back into the "no power" mode. I would expect throttle movement to trigger this issue.

Also this doesn't fit with the fact that the vast majority of the time unless you've just come off the motorway (on overrun) up the slip road (when it can then do it when you try to pull away - which is very scary), it otherwise generally only happens above 50mph.

I still believe deep down this is some sort of fuel starvation issue, I just don't know what is causing the starvation, and all of the parts repsponsible are all expensive to replace, so trial and error replacement (of injectors, common rail, or fuel pump) is not a cost viable solution, if it were I'd simply replace the lot.

Thanks for trying though, all the help is appreciated, and I am following them all up as time allows.

[phitchen]

On my assumption of a fuelling problem can you read "real time" fuel pressure with an OBD2 monitor ? from the connection port with the car running ?

Anyone know ?

[Bod & Hammie]

Hi Pitchen,

Did you get this sorted as I am starting to experience similar issue but in a smaller way?

Thanks,

Bod.

[Versod4d]

Hi,

I have a Verso D4D on an 03 plate. I have had lack of power on this this for a few months that appeared to come and go. Then i had a couple of warning lights on the dash that would be very intermittent but were off most of the time. Anyway, just beofre i took it to the local garage to get the code diagnosed, i had to do a run down to somerset. On this journey i suddenly suffered yet more power loss and then a mechnical noise followed by a serious plume of blue/black smoke. Turbo packed up!

I dont know if this is your problem, but the early signs with mine were similar to yours.

I have inspected the turbo and the bearings have collapsed. I will be doing the replacement myself as Toyota quoted me 3.2K for the privelage!

[nortones2]

Just a thought re MAF and VNT: have a look at http://www.tdiclub.com/TDIFAQ/TDiFAQ-8.html#e1 which might help?

[PhilGee]

EGR faults are normally more common on the later diesel engines. Alot easier to get to and clean!

Alot of the performance issues caused on this engine that i've come across have been the Suction Control Valves. If you get a diagnostic machine that reads live data then you may be able to read the fuel pressure readings. If this reading drops when you get the lack of power then theres a good chance its the SCV's sticking. From what i've found you can test the valves and the readings are normally in spec but its when they are operating the moving parts actually stick, causing the drop in fuel pressure.

Hope this helps.

[phitchen]

Hi,

I have a Verso D4D on an 03 plate. I have had lack of power on this this for a few months that appeared to come and go.

<snip>

Turbo packed up!

No my fault is not turbo related.

As I think I may have mentioned above, I am a Chartered Mechanical Engineer, so I'm pretty good at the feeling that different faults give, I can't describe it any better than that, but I am 99.9% certain (never say never) it is not a turbo fault. Anyway, had one of them on my Subaru STI, and it was nothing like this, but also nothing like you describe yours either.

[phitchen]

OK then now for an update.

It's gone......

As I menitoned above we got to a point where you could absolutely repeatably create the fault, especially on the motorway, by driving along at a steady speed. Lift off the throttle totally for a few seconds, then try to accellerate, (i.e. coming up behind a slower vehicle, and waiting for an opportunity to pull out and overtake) and nothing would happen. The only way to get recovery from the fault was either to stuff it into third and rev it hard, then it would recover, or just dip the cluth and stick it onto the rev limiter for a few seconds. However with both of these methods there was no guarantee as to how long the problem would go away, it may be minutes, hours, or just seconds before it reoccurred.

Now by pure chance the last couple of tanks of fuel have been Shell, and by the second tankfull, the problem had virtually vanished, ocurring maybe once in a several hundred mile motorway journey, and now after about another 3 tanks of branded fuel (Shell, Esso and Total), it appears to have gone completely.....

So I'm guessing I had the sticky goo stuff from the supermarket fuels (as we predominatly have always filled it with Tesco fuel - for convenience rather than cost as our local Shell it typically as cheap as the supermarkets anyway), however I already checked for this and could find no evidence to support the presence of it, the fuel filter was spotless, but I changed it anyway as it was no genuine.

So, I still don't know what the actual problem was, I still believe that it was fuel pressure control related but had no way to check, and now that the problem has gone, I guess I will not now find out unless it comes back (but I rather hope that it doesn't).

[Bizzle]

Hi Paul

I am glad that you appear to have solved your problem concerning the loss of power and your experience concerning the fuel will benefit all of us.

I have a common problem that you may help me with concerning the lack of an owners manual following my recent purchase of a 2.0 D - 4D T2 on an 05 plate.

Is it possible please for you ( or anybody else ) to provide me with a photo-copy for which ,of course , I will pay a reasonable amount.

If you ,or anybody else, can help please contact me on 0208 778 5350 or by email pgblake@ic24.net.

Best Regards

Peter

[bluesky2008]

Hi,

I've got the same problem as OP.

Loss of power, especially 4/5 gear. Also problem with starting, when engine hot/warm.

Tried cleaning EGR, new Fuel/Air filter. No change. Stil the same problem.

Tried full tank of V-Power Shell with BG244 cleaner as well. Tank nearly empty, but no much improvement.

Looks like it is SCV valves issue.

Is it possible to try to clean them (ie. with carbon cleaner), or I am better off just getting the new ones.

Not cheap though, £200+ for a pair.

Avensis, D4D, 2.0, 51reg. Mileage 98,000. Serviced regularly.

Thanks

[smartini]

This loss of power has now happened to me - twice!

First time was a few months ago on the motorway, just about to overtake but had no power to accelarate and ended up having to coast across two lanes of busy traffic to the hard shoulder. Very scary! I actually thought it was me so did nothing about it.

Yesterday, it happened again, fortunately not on the motorway. I was accelarating and moving through gears after coming off roundabout. Went into 4th but no power, moved down to 3rd but still didn't respond, then saw load of dirty smoke in rear view mirror (no noises or anything). After I pulled off the road and moved through gears car drove perfectly.

Off to garage tomorrow to see what they say.