I've been reading threads on EGR valve issues, blanking and restrictors. While I have an '06 Croma, this is applicable to all 1.9 16V JTD engines. I don't like the idea of complete blanking as it increases emissions, is technically illegal in the UK and needs an ECU update on 16V engines to prevent a failure being detected. So I've got the official restrictor plate, the later 55225287 type with integral gaskets. This is a thin plate with 4 holes each about 7mm diameter. While this obviously reduces the open area of the outlet port, what does it do to the flow? According to eLearn the EGR valve solenoid is driven by a square wave "modulation" signal. Allowing for translation, this indicates a pulse width modulation (PWM) scheme that controls the average current through solenoid and thus the amount the EGR valve opens. The management system adjusts the pulse width to control the valve in a closed loop system. The mass airflow sensor provides feedback. If this is correct, putting a restrictor plate will not change the amount of gas recirculated, except for the EGR valve fully open case. If you just wanted to reduce the flow it could be done with an ECU update, no "spannering" required. I can see three possible effects of adding the plate.
1/ The EGR Valve will have to open further to get the required flow. This will probably reduce build-up and clogging in the valve as the opening will be bigger and the parts will move over a longer distance with more force applied.
2/ There will be more back pressure in the EGR valve. I can't see any advantage here but have not looked closely at the valve design.
3/ The exhaust gas will enter the inlet manifold in 4 high(er) velocity jets rather than a slow bulk flow. This may help mixing of exhaust and inlet flow due to turbulance etc.
Anyone else have any ideas on what is going on?
Out of interest I'm going to monitor the EGR valve signal before and after fitting the restrictor plate to see if it opens more with the restrictor installed.

OK,
I now have a baseline for the EGR valve opening without a restrictor. Average opening at steady speed is around 39%. I never saw over 45%. This was via EOBD with the demo version of AlfaObd for Android running on a Samsung Galaxy note II and a white coloured bluetooth ELM 327 interface by ProScan see link below
< [ame]http://www.amazon.co.uk/Bluetooth-Wireless-Diagnostic-Android-Motorola/dp/B00CP3L9PA/ref=sr_1_25?m=A5845Q5NMIKH7&s=merchant-items&ie=UTF8&qid=1425135897&sr=1-25[/ame] >

When I've fitted the restrictor plate and let it run for awhile to re-adapt I'll give an update.

I have driven the official 4 hole restrictor plate in my 2004 Alfa GT jtd 16V, but didn't notice much difference.
As I was completely done with the thick, heavy Dieselsmoke at full throttle, I went to a chiptuner, and had the EGR electronically shut.
I even used two blanking plates, to be absolutely sure everything is, and will stay closed.
Since then, no more heavy smoke, cleaner engine oil, cleaner rearside of the car etc.
No problems with Dutch Mot either.

So I fitted the restrictor plate today. Really easy, I've posted a guide (in the guides section) with photos. The EGR valve hs two poppets with a fairly heavy spring closing them and the solenoid acting against the spring to open it. As the spring force is proportional to displacement and the EGR command goes from a percentage open to zero (closed) in one step at times, it will close more forcefully from larger openings. I'll give it a couple of days to settle and then take some new readings.

Roert G8RPI.

So, after a week of normal driving, no long trips, I did a test run monitoring the EGR command. The results were not what I expected. The EGR valve control range has reduced. The minimum is now 4% (was 0) and the max about 35% (was 45%). So I was wrong, the ECU is not trying to open the valve more to compensate for the restrictor. This seems to indicate it is opened to a schedule based on temperature, load, revs or whatever. If it is, then the restrictor is actually reducing the EGR flow. This is good. I think the difference in command I'm seeing is due to the ambient temperature being 10 degrees higher. The ECU may only be using the mass airflow change with EGR opening to detect EGR valve failure. I'll look at the EGR command again in a few weeks to see if any thing has changed.

If you take the restrictor plate out now, you'll be amazed to see the amount of carbon/sooth build up around the four holes...
All that dirt is sucked into the engine all the time....

Peter Pick-Up said:

All that dirt is sucked into the engine all the time....

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Yes, but it came from the engine in the first place . The AdBlue / Bluetech systems are the latest way to reduce NOx emmisions, but thats even more stuff to go wrong. EGR is not ideal but its what we've got. Wait till they start putting DPF's on petrol cars, that will force the use of plug-in electrics if you only do short trips

Sure it came from the engine, but no reason to suck it in again...
I'm happy with the closed EGR, and removed catalyst on my Diesel car..
Keep it in top tuned condition, use only premium fuel, and don't worry about pollution at all.

Peter Pick-Up said:

.
I'm happy with the closed EGR, and removed catalyst on my Diesel car..

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Unfortunatly that is illegal in the UK and they have (or should have, they have not updated the testers handbook yet)) been checking it since early last year at the annual "safety" check (MOT).

How will they know?
MOT is the same all over Europe, I removed the two catalysts 4 years ago, and blanked the EGR 1 year ago, been to our MOT without any problems since...

Hi,
How they will "know" in the UK is not totally clear. Initial guidance is visual inspection only so a "cored" CAT or DPF is less likely to be picked up than one with a straight pipe replacement. However the formal inspection handbook which gives detailed guidance has not be updated to include this requirement (last time I checked, a couple of weeks ago). Obviously one thing would be to check the lambda sensor readings and ECU firmware via the EOBD port. Checking the emissions equipment was working OK was the reason for mandating OBD in the first place. This will work for simple ECU deletions, but the chippers could simulate the sensor readings. It would however be a program change, not just a deletion of map value adjustment. The MOT testers could have a list of valid ECU firmware versions and checksums but that's a lot of work and unless the EOBD reader can access the ECU memory directly, checksums can be spoofed. The same goes for a visual check, The tester might know what a Ford Focus CAT should look like, but how many Cromas will they have seen?
But having an MOT test that does not detect removal, or an inspector that is not diligent, does not mean that the offence has not been committed. Here in the UK VOSA do carry out roadside checks that go much deeper than the MOT. Another way you can lose out is if you have an accident, it is possible that the insurance inspector will detect the deletion and void your insurance. Both of these are very low probability, but still a risk.
It's a personal decision, but I do point out the legality issue so others, who may not know about it can make an informed decision.

ive been thinkig of a blanking egr plate as i have a problem with my 1.9 jtd 16v the multiecuscan shows the egr at 100% when i floor it and it sometimes goes into limp mode

Guide here
https://www.fiatforum.com/miscellan...v-mjtd-egr-valve-restrictor-installation.html

thanks for the info but still confused about the valve showing 100% when on the gas does it mean its closed or open as the lose of power is really noticable

roveital said:

ive been thinkig of a blanking egr plate as i have a problem with my 1.9 jtd 16v the multiecuscan shows the egr at 100% when i floor it and it sometimes goes into limp mode

Click to expand...

The 4 hole restrictor gasket is useless, it still allows loads of sooth and dirt into the engine.
Have a chiptuner delete it from the ECU, and blank the EGR to be sure it's closed 100%.

Peter Pick-Up said:

The 4 hole restrictor gasket is useless, it still allows loads of sooth and dirt into the engine.
Have a chiptuner delete it from the ECU, and blank the EGR to be sure it's closed 100%.

Click to expand...

Hi Peter,
It's been mentioned before, and I don't want to go into the pros and cons, but deleting an EGR, coring a DPF and similar modifications renders a vehicle illegal for use on the road in the UK and most, if not all, EU countries. I think that if you recommend such modifications you should include a disclamer or "health warning" about possible legal issues.

Robert G8RPI.

Driving fast is illegal as well...
Health warning...??
How many nuclear powerplants in the UK...???
Come on, strictly speaking it maybe illegal, but drivability benefits a lot, and almost every chiptuner worldwide deletes the EGR during remapping anyway.
Our MOT is as tough as yours, but my smooth running and powerfull 1,9 Turbo Diesel never fails...!! ( even without two catalysts and closed EGR...)
Btw, today 310.000km's (~195.000mls), we're about halfway.

It's a question of liability. Would you send someone a letter encoraging them to commit murder? Steal a car? Break the speed limit? Break eimmisons rules? It's a matter of degree but they are all promoting illegal acts. If someone modified a car on your advice and got a fine and a bill for restoration, they could in theory sue you , or possibly the forum, for your "advice". Unlikely I know, but there are more and more people out there who don't take responsibility for their actions, and lawers who will take up such cases.
I have lots of opinions on lots of things (I think nuclear power, especially fast breeders, are the only mid to long term solution to the energy problem, but lets not get into that), but I don't express them on internet forums or email lists where someoe can find them later and use them to my disadvantage.
It's also not fair to suggest a possibly illegal solution to another member who may not be aware of the relevant laws.

Peter Pick-Up said:

The 4 hole restrictor gasket is useless, it still allows loads of sooth and dirt into the engine.

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Well it workes for me and at least one other, see https://www.fiatforum.com/grande-pu...bhp-multijet-egr-valve-fault-2.html?p=4080242

Robert G8RPI.

No holes blanking plate works for me.
320.000km= 200.000mls and still going strong