TD4 EGR Idea

What happens if you unplug the power supply to the egr solenoid. Would it stay closed or upset the ecu/throw up a fault code. Just because when you block the vac pipe the ecu still tries to open the EGR and expects to get a different MAP reading combined with the MAF reading. Dont really know just putting it out there.

upset the ecu/throw up a fault code

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my 10p be on the ecu having a tantrum

and expects to get a different MAP reading combined with the MAF reading

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how do you figure the ecu Expects that ??
should it not not just take those readings as the voltage info arrives at its' circuitry ?

i.e. it's not like the map and 'maf sensors are faulty .. and causing the ecu to use default parameters ..

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disclaimer .. i've not tried unplugging the egr solenoid to see what it may or may not do ..
convincing the ecu that the egr unit is still attached seems to be the safer option
( 'n let the map and maf do their sensing with the improved air flow )

My understanding is that the ECU opens the EGR valve more or less depending on the MAF reading and some how it works out how much fuel to inject depending on the combined pressure of the exhaust and inlet. I dont think the ecu has any way of knowing that the egr is open or not it just applies a vacuum for a period of time. So if the ecu thinks the egr is open but its not the amount of fuel might be different to when the ecu thinks the egr is closed and the MAP sensor reads the same pressure. For example when the EGR sticks open the ECU thinks more clean air is going in than it does and causes a problem, so my theory is that When the EGR is blanked it thinks the engine is getting exhaust gas when its not and may adjust the fuel accordingly. If the ECU cant see the solenoid it would never expect exhaust gas to be in the intake and always fuel correctly according to the MAF.

If the ECU cant see the solenoid it would never expect exhaust gas to be in the intake and always fuel correctly according to the MAF.

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i see what you're getting at now

maybe i'll test that theory after m.o.t. on monday ..
can't hurt to try i guess ..
i still rekon the ecu may throw up a warning dashlight .. record a fault code maybe

maybe best way to do it .. would be to wire the egr solenoid connector
so that it shows the ecu .. that the valve is always 'open' ..

food for thought ..

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only way to know 100% for sure ..
is to understand exactly how the ecu works ..
that info seems be scarce via the internet ..
would need to read bmw/lr technical notes .. and maybe have a particular comp/software to hand
( just speculating )

come to think of it ..
that data might show up via diagnostics ..

as my insurance premium went up due to the addition of a synergy2a tuning box ..
i was entertaining the idea of getting a remap ( and ditching the synergy ) ..
although would mean reverting to bosch maf as well ( have pierburg at moment )

and with a remap .. they normally test the engine for airflow 'n such .. ..
so i figure certain data would show up re. what your talking about above ..

actually .. being able to diagnose via a computer .. and alter the engine parameters
is something i'd like to be able to do .. but i think the equipment costs a bomb ( for starters )

do you know the exact difference between the synergy 2a and 2e looking at getting one of these boxes but cant see the difference.

My dads friend is the owner of dakar in dartford a land rover specialist and original creator of the dakar kit car. he offers a remap from autologic but i think the synergy is better as you can take it with you and if you bought second hand can sell for what you paid for it. to be honest i want more fuel economy more than anything else and the 10 settings should offer the best advantage. Not sure how much a remap from autologic costs but guessing its at least a couple of hundered pounds will ask next time i see him.

dan1985 said:

do you know the exact difference between the synergy 2a and 2e looking at getting one of these boxes but cant see the difference.

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2a can give loads more power. 2e only allows eco settings. No added power, just some torque settings. I've got a 2e and insurance company were not interested.

do you know the exact difference between the synergy 2a and 2e looking at getting one of these boxes but cant see the difference.

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without re-reading the site info ..
i think the 2e ( economy ) doesn't increase the engine horsepower
and probably works via the maf values to potentialy give better economy
plus the option to use a pierburg maf ..

the 2a has .. apart from various power settings ..
a cab switch that turns the power 'off' .. or gives two economy settings
'n the cab switch enables the user to switch those settings without turning the motor off.
the economy setting work via the maf values ..
i.e. lower voltage values decrease the available fuel supply at a given go-pedal position

something like that ..

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i get 40mpg plus with the 2a on any 'power' setting ..
( i don't use the in-cab switch as i've not connected it now
( but did try it out .. although left it in the engine bay ..
came to the conclusion ..
economy be mainly down to right-foot anyway .. and gear usage .. so on and so forth ..
have always left the power on highest setting ..
been driving on snow and some ice .. no problem

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btw .. re smoke on cold start .. ( cold ambient temp i.e. 0c or less today here )
i never really checked mine before .. except for today ..
was smoking and smelled of unburnt fuel ..
stopped 500 yard down the road to clear some side ice off the windscreen
engine temp had reached 50c .. smoke 'n pong had vanished ..
( idle rpm )

No added power, just some torque settings.

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so better go-pedal response at low rpm ..
that's useful .. i.e. compared to standard mode

a remap from autologic

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was thinking down the 'autologic' route ..
be a 4by4 outfit near leeds that do it ..
i did phone them to enquire some months ago

then i thought .. what If the remap got wiped from the ecu ..
and the remap outfit had gone bust ..
figure if the remap data file could be saved to cd ..
and re-installed via cd ..
then i might consider it ..

synergy be costing me an extra £24 per month on insurance ..
not a huge amount .. although over a year it's near the cost of a remap ..
then again .. a new bosch maf ain't cheap either ..

dunno .. i'd just like to try it 'n see how the vehicle drives ..
given that engine parameters like 'injection timing' can be altered as well
( as opposed to just? fuel injection pressure 'n maf values with the synergy )