Reply With QuoteUnlikely to be limp mode, more likely your Suction Control Valve is on the blink - do a search, there's been a few related threads of late.
Master
Mmmm where do i start?
So far over the past two days, I've had the 2.4 go into Limp mode 3 times. The revs won't go above 1500, can only proceed at 40kh, but no MIL lights.
There doesn't seem to be a pattern......yet! The first two occasions were yesterday, going up from 2nd to 3rd, changing at 2200rpm, engine temp normal (85), level ground and no real load on engine.
Third time I had the BAS2RRC hooked up as I traveled to work this morning. Logging the live data. Again flat ground, no engine load, engine just coming up to temp (78), but this time changing up from 5th to 6th at 2500rpm. All data was as should be. Throttle sensors 1 and 2 all good, fuel rail pressure as should be. EGR turned off with city map and physically blanked.
Checked for faults, and none logged.
The fuel filter is only a 1000k's old, as I've just completed the 80,000k service. Drained and all good. No sediment.
I've just cleaned the MAF and MAP sensors and took for test drive, at this stage all good, no limp mode.
Next step, tomorrow, is to remove the turbo and intercooler hoses, for closer inspection. They seem ok fitted up, no obvious splits, cracks or rub marks. Clamps seem ok. They are the original LR hoses, haven't quite got the money together yet for a set of silicons. I was thinking maybe the BAS Re map, which has been on now for about a month, has exposed a weakness in the LR hoses. Possibly causing delamination. I've had turbo hoses let go before on a couple of work trucks, generally there's a fair bit of noise involved and all the check lights come on.
The Defender just gave up quietly, no noise, no lights. The second time was a bit disconcerting, as I was pulling out of a side street onto the main road, and there was nothing, no power. Luckily it was 5am with no traffic. Before it happens, the engine is performing fine, no flat spots or hesitation, plenty of torque. There is absolutely no warning signs before it drops into limp mode.
It was suggested that it could possibly be the fuel pump, but wouldn't that light up the MIL and throw a code or two?
Next step will be to fork out for some silicon turbo/intercooler hoses, but to be honest I'm at a bit of a loss trying to figure this one out, especially as there's no MIL or codes being logged.
So any suggestions would be greatly appreciated, thanks.
Unlikely to be limp mode, more likely your Suction Control Valve is on the blink - do a search, there's been a few related threads of late.
Master
Yeah thanks, could possibly be the SCV, VCV. But my idle is fine, even on very cold mornings. No hunting whatsoever, plus it doesn't feel like it's going to stall.
The engine drops to idle, I can travel no faster than 40kmph, and the engine will only rev to a max of 1500/2000rpm.
It looks simple to replace, and I can do the pump learn with the BAS tool. Definitely something to think about, many thanks.
In my experience you won't get hunting at idle until the problem gets worse - at first you'll just get lack of power and no MIL. This typically happens during large changes in throttle setting i.e. accelerating up through the gears.Originally Posted by ozy013
I only got stalling once the problem had got so bad the car was basically undriveable.
What I did pick up though was that during the fault my fuel rail pressure would drop off - this was easily detectable just with a Scanguage.
Other possible causes that spring to mind are the Cylinder Head Temperature sensor (which supposedly drives the limp mode fault, rather than coolant temp, though I've never got a definitive answer as to which one actually causes a limp condition) or your throttle position sensor i.e. the throttle.
Master
Just a quick update, it's certainly looking like the VCV is the culprit, thanks again n plus one.
I have a LongRanger 120ltr tank, and a few months ago i did notice a jelly/silicone like substance when I did a routine drain of the filter. I ran a couple of bottles of the Wynns cleaner through the tank. Complete Fuel System Cleaner Diesel - Wynn's Australia
The damage however could already be done as the VCV is very sensitive to contamination within the fuel system.
The new filter hasn't picked anything up........yet. But after chatting on Defender2, they have confirmed what you said earlier. I will also check the inlet ports on the filter housing as it's possible they could be blocked.
It was recommended that i use these products,
Wynns Dry Fuel
Archoil AR6400-D Pro Diesel Cleaner PEA Concentrate
Is there any similar product here that you know of?
I was just looking again at the data I logged when it did it the third time, and there's no real noticeable drop in the rail pressure. It follows both accelerator pedal sensors and the rpm pretty much all the way through the time it was logged.
I think I'll keep the BAS tool hooked up for the next few days, see what I can find.
Thanks again for your very helpful post, cheers.
OldBushie
I found the Transit Forums are the best source of info on our TDCi's because those guys have been running these engines a lot longer than we have.There is lots of info on the VCV,I'm going to look at mine as a service item,like the injector harness on a Td5,they are cheap ex UK. Pat
I'd be in two minds about checking the inlet ports if I were you - I checked mine and found a) they're were clear ,b) they're a bigger to undue and the clips are easily damaged and (most importantly) c) it's very easy to introduce contamination into your fuel system on the pump/injector side of the filter.
Just my experience, but I'd suggest buying an SCV online (I got mine on Fleabay from a diesel mob in Perth for about $250) and changing it as a first step - they're a known fail point and if I doesn't fix your issue you have a useful spare part for your kit!
Fossicker
Wot the hell are the SCV & VCV's ? Ian
Suction Control Valve/Volume Control Valve/Pressure Control Valve - all the same thing. The regulate the low pressure (suction) side of the high pressure common rail fuel pump.
They play up in heaps of common rail diesels (probably cos' Aus diesel is crap) - if you take it to a dealer they normally 'fix' it by replacing the fuel pump, the rail and the injectors and charging you $10k plus. Or you can do it yourself for a couple of hundred bucks and an hour of your Saturday morning...
A Keeper of the TGO
These are the ones I was thinking of Friday Ian but could not remember their names
I knew I'd read of them playing up before which is obvious from the posts.
Suction Control Valve & Volume Control Valve.
Have a look at YouTube to see what they do, it worked for me to clarify things.
Below is from RAVE....
A VCV in the HP fuel pump, controlled by the ECM, regulates the supply to the pumping elements depending on the fuel pressure in the rail. This ensures the delivery from the pump matches the requirements of the engine. When the engine is at idle speed, pump output pressure is in the 220 - 250 bar (3190 - 3625 lbf/in2) range; at typical driving speeds, pump output pressure is in the 1300 - 1600 bar (18850 - 23200 lbf/in2) range.
Last edited by alien; 16th August 2015 at 08:15 PM. Reason: Add RAVE explanation.
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