egr block yes or no ?

Cheers Simon

Just fitted the EGR delete plate the van does feel a little smoother to drive but has no real performance gains on my 85, it was a little bit of trouble to fit but its on now and there it'll stay.

by fitting a blanking plate does is throw a ecu light in the cabin,
also by blanking off the pipe that does not stop the valve flap from moving so how does the engine get its air when the flap is in the position to get air from the exhaust
or have i got this wrong umm
matt

I`m a bit confused now. If you read touche`s post on page one he makes reference to stopping the egr by either blocking the vac pipe or doing an egr delete. Presumably both of these methods work by disabling the valve. The plate works in another way does it? by physically blocking the pipe from the exhaust ? The valve must be fail safe close then , so the neatest solution would be egr delete? 

wont fit mine 
mines the 174 AXE motor
id still like to blank it off anyon got a pic of the hose?

In theory the ecu SHOULD see the egr open by seeing a drop in the maf readings, this is generally how it monitors egr operation which it needs to do, EGR = Less fuel required due to the egr flow being oxygen depleted. Deleting EGR will leave the fueling slightly lean when egr should normally be on, the way i see it is that this shouldnt be a problem as egr can only operate when boost is less than exhaust pressure, maybe 6psi?? I believe you can tweak the system with Vagcom to reduce egr rate, this helps to correct the minor underfuel.
I question the systems capability. My egr pipe is blocked and i have no light on. I suspect that the ecu calculates fueling mainly from boost readings.
I am relying on the seal of the egr poppet valve (which shouldnt be an issue) rather than a blanking plate but when I get a remap I will fit a blanking plate or an allard egr delete.
A remap is the way to go to fully delete egr and correct the fueling.

Just fitted one of Mr Baxter's blanking plates to my 2.5 AXD engine and it fits perfectly. Not tried it yet, but off to Wales tomorrow to paddle the Wye, so will try it out then.

Baxter wrote: You can't have a lean mixture on a Diesel. Less fuel per volume of charge air just results in a engine that turns slower.

at idle, i would agree. But the same cannot apply under load/when driving, the ecu fuels according to metered airflow into the engine, therefore fueling can be rich or lean at any point determined by how much fuel the ecu injects to match determined airflow.
Obviously diesels are less fussy about the air fuel ratio but there are still optimum ratios for performance and for economy.

It would be good to know how the ecu determines fueling for egr operation, i.e. does it reduce fuel:

A) when it requests egr,

or

B) only when it sees the requested egr drop the maf reading.

for us egr deleter's, hopefully the latter.

All the above assuming no oxygen sensor. I wonder if some egr deletes put the eml on because the vehicle has an o2 sensor and can measure fuel/air ratio more accurately.

touche wrote: Baxter wrote: You can't have a lean mixture on a Diesel. Less fuel per volume of charge air just results in a engine that turns slower. at idle, i would agree. But the same cannot apply under load/when driving, the ecu fuels according to metered airflow into the engine, therefore fueling can be rich or lean at any point determined by how much fuel the ecu injects to match determined airflow. Obviously diesels are less fussy about the air fuel ratio but there are still optimum ratios for performance and for economy.

I'm sorry, but you are still quite wrong.  I respectfully suggest you do some research on how diesel engines work before you try to tell us how you think they work - they are very different to petrol engines due to the lack of a throttle plate.

gregozedobe wrote: touche wrote: Baxter wrote: You can't have a lean mixture on a Diesel. Less fuel per volume of charge air just results in a engine that turns slower. at idle, i would agree. But the same cannot apply under load/when driving, the ecu fuels according to metered airflow into the engine, therefore fueling can be rich or lean at any point determined by how much fuel the ecu injects to match determined airflow. Obviously diesels are less fussy about the air fuel ratio but there are still optimum ratios for performance and for economy.   I'm sorry, but you are still quite wrong.  I respectfully suggest you do some research on how diesel engines work before you try to tell us how you think they work - they are very different to petrol engines due to the lack of a throttle plate.   Diesels run on variable air fuel ratios, and use the amount of fuel being injected to control power :  less fuel (leaner) = less power, more fuel (richer) = more power (up to a point, then it will damage the diesel engine).   Diesels work very well indeed on lean mixtures that would quickly kill a petrol engine, and the rich mixtures that stop a hard working petrol engine from overheating would kill a diesel.