Engine cuts out at 3000 rpm after Synergy 2a fitted ??

Hi everyone, and i hope you can help me ! Ive trawled the threads and found a lot of similar problems but none specific to the below as far as i can see.

Recently got my 2006 TD4, 74000 miles and in good all round nick. I had a major service including all oils, filters, BMW crankcase mod fitted and running well, cruises on MWay at 80-85 no probs. So heres the problem - I have just fitted a Ronbox Synergy 2A and Pierburgh MAF, EGR bypass and replaced all hoses with silicon ones. The car now cuts out at 2500-3000 RPM and the right hand side engine warning light comes on. If I try and boot it to get going again there is nothing and the car just grinds to a halt and engine cuts out. Ignition off and on and warning light goes out again, car starts fine until the next time I try and floor it. If I turn off the 2 switches on the ronbox the car is very sluggish to around 2000 RPM, I assume thats because im essentially bypassing the new MAF ? but the car will then go right up to the redline with no warning light coming on and no engine cut out. Any one got any ideas, im baffled ! Checked all the vac pipes, actuator, boost solenoid and they all seem to be OK. Any help is appreciated before I disconnect the Ronbox and put the old Bosch MAF back.

Thanks,

Chris

probably the low-pressure fuel pump and/or fuel filter

the synergy2a will put a greater demand on the l.p.pump
and also the flow capacity of the fuel filter
@ 74000 miles the lp.pump is towards the end of it's life
and if the fuel filter has never been changed .. it's overdue

If I turn off the 2 switches on the ronbox the car is very sluggish to around 2000 RPM, I assume thats because im essentially bypassing the new MAF ?

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if you've the pierburg Maf then just leave the Maf switch turned on
( and turn the power switch off )
btw: with the p.maf .. you can use all 10 settings on the ronbox
if you use the bosch mac settings ( 1 - 5 ) you'll simply get a slightly weaker maf signal
i.e. the same as you'd get with the bosch maf installed

Thanks HD3,

The fuel filter was replaced at the recent service, so not that. Is there any easy way to check the LP fuel pump ?

Also, by turning off the power and leaving on the MAF switch what will this show, sorry this is all relatively new to me !!

Thanks

Firstly don't tell us you break the law.

Next, replace your low pressure fuel pump.

To test it remove it and replace it. Takes about 1 hour start to finish and costs £140-£170. Only buy a genuine one as the pattern ones are generally noisy and don't last very long.

Trust us, we have all been there and had the same symptoms.

The tuning box or a remap will exaggerate and highlight ANY existing problems you have with the car. It will not give you any new ones despite what you may think!

The low pressure fuel pump seems to last from 60-120,000 miles.

Thanks Epicuser !

Will certainly look at the LP fuel pump but why did it run ok before the ronbox was fitted, didnt miss a beat ? Confused ??? !!

I don't have a TD4, but I've read a lot of these types of thread and I'd agree it is most likely the fuel pump. I wouldn't say its definitely the fuel pump, because there's a multitude of sensors on the TD4 that give trouble - but this does look like fuel pump symptoms.

Fitting a Ronbox changes the demands on fuel for your engine - at times it may need less, at others more. It appears you're hitting a point where more fuel is needed and your aging pump can not keep up.

chrisflak said:

Thanks Epicuser !

Will certainly look at the LP fuel pump but why did it run ok before the ronbox was fitted, didnt miss a beat ? Confused ??? !!

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As mentioned above, to increase power it increases fuel pressure. If the pump is getting weak then it just can't keep up with demand.

Turn off the Ronbox until you have replaced the pump.

It might be a sensor, but in the majority of cases it is the pump.

It is worth doing regardless at your Freelander's age and mileage.

PS. This is probably the most common problem with the TD4.

Epicuser said:

PS. This is probably the most common problem with the TD4.

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It's the HGF of the TD4 - and a lot easier to fix

GrumpyGel said:

It's the HGF of the TD4 - and a lot easier to fix

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And cheaper

Thanks everyone, is it ok to just switch off the ronbox and leave the new MAF in or should I disconnectvthe box and refit the Bosch MAF ? Thanks all for your kind help

Just turn off the power setting on the Ronbox.

So now I'm more confused ! With the power (fuel) switch off and the Air (maf) switch on she actually runs quite well, but gets to 70 and rather than cut out just goes into limp mode with the yellow engine light illuminated. The car is still drive able like this and does not cut out like when both switches of the ronbox are on, does that point to anything ??

I'd say that's more like the typical symptoms reported with the TD4 - probably fuel pump, possibly sensors.

So now I'm more confused ! With the power (fuel) switch off and the Air (maf) switch on she actually runs quite well, but gets to 70 and rather than cut out just goes into limp mode with the yellow engine light illuminated.

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on one of these pages .. down the bottom
be a list of Maf signals
the stronger the signal .. the more fuel be injected
the Maf sensor is effective 'till about 2500 rpm

td4 engine faults :
ROVER 75 MGZT ENGINE FAULT FINDING

about the 'maf' sensor :
Maf sensor problems.

~~~~~~~~~

another thing that Might cause the rpm hitting a brick wall at certain rpm
be .. if the turbo is over boosting ..
the ecu will cut power to prevent damage ..

check that the turbo vent filter was replaced at service ..

the turbo is a variable vane angle type
and relies on a vacuum solenoid to actuate the vanes ..
if the actuator gets stuck / or the filter gets clogged up
then the vanes don't operate properly ..
resulting in possible turbo overboost .. or underboost ..

( safari's spellchecker is doing my head in .. grrrrrrr ;-)

in anycase .. at your mileage .. the lp.fuel pump be near the end of it's days ..
and they are not re-buildable .. only choice is the buy a new one
( usually the brushes wear on the electric motor )

i was told .. the lp.pump works all the time
but some of the time it 'freewheels' due to an internal valve
i imagine when the go-pedal is down .. the lp.pump has a good workout ..
but when cruising on part pedal it's not having to work much ..

usually the pump gets noisy towards it's end-time
i.e. very audible with the ignition 'on' before starting the engine
a new pump is very quiet .. barely audible ..

Thanks again everyone, and to you HD3 for the last post. Just to update you all, tonight we cleaned the MAP sensor, checked the fuel rail sensor and both were clean so does not look like that is the problem. As I have now an EGR bypass fitted, we also swapped the boost solenoid with the EGR solenoid as they are the same part. Has made no difference to the problem. The turbo has been checked, and as far as we can tell the vanes are opening as the arm moves freely, the turbo vent filter has also been replaced. Which i guess only leaves the fuel pump, especially as the car was running fine until we fitted the synergy 2a and pierburgh MAF, and it is quite noisy, clearly audible from the cab, my only question is why would the systems persist with the synergy fuel switch off and the MAF switCh on, does the new MAF mean more fuel even if the fuel switch is off ? Anyway, the car is quite driveable as it is so im going to get a new fuel pump anyway and hopefully get it fitted next week, will keep you all informed !!

Cheers

Which i guess only leaves the fuel pump, especially as the car was running fine until we fitted the synergy 2a

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makes sense

does the new MAF mean more fuel even if the fuel switch is off ?

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i don't know about the td4 ecu specifically ..
but on reading up about the maf sensor as fitted to a common-rail diesel engine ( like the td4/m47r engine )
.. and the example was another brand/make of engine ..
the maf sensor signals determine ( or effects ) for how long the injector is 'open'
i.e. fuel pressure remains the same ( more or less ) .. but the timespan for the injector being 'open' changes .. thus allowing more ( or less ) fuel to be injected without upping the pressure level by much

chrisflak said:

Which i guess only leaves the fuel pump, especially as the car was running fine until we fitted the synergy 2a and pierburgh MAF, and it is quite noisy, clearly audible from the cab, my only question is why would the systems persist with the synergy fuel switch off and the MAF switCh on, does the new MAF mean more fuel even if the fuel switch is off ? Anyway, the car is quite driveable as it is so im going to get a new fuel pump anyway and hopefully get it fitted next week, will keep you all informed !!

Cheers

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Because it is now fooked

When they go that's it.

My car started off at a 3000rpm ceiling and after a few days got down to about 1500 before my replacement arrived.

Ok so the plot thickens

Have now replaced the fuel pump but the problem is still there. So I also removed the Ronbox and replaced the new MAF with the old Bosch one and it's still there even when all back to std (apart from EGR bypass and silicon hoses that are still on) !! The only thing I can think is that when I gave the car a good blast after the box was fitted I have somehow got the vanes stuck or something in the Turbo because the car has not been right since and it ran perfectly before the mods. Does this sound feasible ? Just to recap, I have checked and cleaned MAP and fuel rail sensors, replaced fuel pump, and fuel filter and turbo vent filter have also been changed recently. Have also swapped over the old EGR solenoid with the boost solenoid to make sure it wasn't that. Any help gratefully received as I'm starting to tear my hair out !!!!
Thanks