Disabling the EGR valve

[shokenore]

Just out of curiosity out of all of you who have disabled the egr valve ,whether by cable ties/ball bearing or by going down the blanking plate route,how many of you are still running that particular truck or more importantly that head?

Also did you actually record any real life benefits?


Your comments as always gratefully received .

[POPEYE]

Did mine several years ago and no trouble, i went for complete removal and blanked off both ends at the manifolds, theres no sudden rush of extra power but along with several other mods i guess it makes the running better, mine certainly is much better than when i first bought the truck, i did leave the wiring plugs attached to their sockets and blanked off the vac tube,, left em connected incase it did summat to the ecg or sensors or whatever,

when i disconnected it from the inlet manifold tho i found the manifold chocka with black oily shite, so that cant be good for eficent running

[NiftyNev]

Most here still think the EGR operates all the time. Not true. Not on the Surf anyway. It only operates at idle and when the engine is up to proper temperature. Removing or blanking off is a good thing to do because it helps keep the manifold cleaner. The manifold will still get dirty from blowby and engine oil so an occasional cleanout is still needed. As for making the engine run hotter and causing cracked heads if you remove or block it, then that's a load of rubbish.

Nev

[tweak'e]

sorry Nev i got to disagree a bit here.

egr doesn't run all the time, most engines turn egr off at full throttle/load and idle. its generally on most other times in various amounts. its generally on a lot at part throttle.

while egr doesn't normally cause overheating or cracked heads, its common for the valves to get stuck in the on position. then your running egr at full throttle. that certainly will overheat and crack a head.
surfs can be bad for it as there is no feedback for the egr circuit so ecu does not know the egr is stuck. on the plus side no feedback means its easy to block off.

even on common rail engines egr systems cause a ton of problems.

[charvell]

So is it good or bad idea to block it off?

[tweak'e]

blocking egr is a very good idea !

only thing i'm not sure on is how to disable the egr butterfly system in the intake pipes on those engines.

[s car go]

blocking egr is a very good idea !

only thing i'm not sure on is how to disable the egr butterfly system in the intake pipes on those engines.

You don't need to! The ECU will carry on operating the small butterfly via constrictor valves A & B.

Regards

Mark

[tweak'e]

You don't need to! The ECU will carry on operating the small butterfly via constrictor valves A & B.

Regards

Mark

thats the problem. you do not want it to operate the small butterfly as per normal. you want it to be fully open and only close on engine shutoff.
if it operates as per normal it restricts air flow and with egr blocked it reduces overall gas going into the cylinder which reduces effective compression.

[NiftyNev]

Should have phrased it better. EGR does not operate anytime, other than at idle, on the Surf. Does not operate at idle, if engine is not up to operating though.

Anyone wants to test this then just connect a vacuum gauge to the EGR Valve hose and see what happens while driving.

Nev

[charvell]

So has anyone done this on a third gen ?

[s car go]

thats the problem. you do not want it to operate the small butterfly as per normal. you want it to be fully open and only close on engine shutoff.
if it operates as per normal it restricts air flow and with egr blocked it reduces overall gas going into the cylinder which reduces effective compression.

Ok then!
The default position of the butterfly is open!
If you apply vacummn at actuator B the butterfly closes. I have'nt worked out how actuator A helps at the moment,as it seems to do nothing,unless mines buggered! Bear in mind mines on the bench presently as the heads gone on my truck!
I can't see how having the EGR blanked off reduces fueling as ths surf does not have an air intake meter.

Regards

Mark

[tweak'e]

i'm not up on what butterfly does what.
the 1kz system looks to be similar to the 2lte. however i threw all of my butterfly setup out.

just need to connect light bulb or vac gauge to the solenoids and work out what one is doing what when driving.
i think the small butterfly half closes while driving which is egr position. it fully closes for engine shutoff. just need to arrange hoses so butterfly closes on engine shout off but doesn't go into half position for egr.
but thats just a guess, i'm sure you will work it out.

some people just rip out both butterflies.

[NiftyNev]

One VSV partially closes the butterfly. This is the hose to bottom of actuator on the 2.4 and i believe the same on the 3Ltr. Top only works on shutdown and needs the bottom one as well to fully close butterfly. Apply a vacuum to the bottom port on actuator and you will see it pull the rod up part way. Apply a vacuum to top port and it will pull the rod up further. The diaphragm in the actuator is two stage.

Both 2.4s and the 3Ltr work in the same way I believe.

Nev

[NiftyNev]

i think the small butterfly half closes while driving which is egr position. it fully closes for engine shutoff. just need to arrange hoses so butterfly closes on engine shout off but doesn't go into half position for egr.

Nope, butterfly is fully open when throttle is anywhere but idle position. This is providing the TPS and everything else is ok. I am almost certain the TPS is what signals the EGR to operate.

Maybe a lot of problems with smoke etc are caused by a TPS not set properly and as a result, the butterfly is closing when throttle is open. A Vacuum gauge is a wonderful diagnostic tool for sorting these things out.

Nev

[s car go]

One VSV partially closes the butterfly. This is the hose to bottom of actuator on the 2.4 and i believe the same on the 3Ltr. Top only works on shutdown and needs the bottom one as well to fully close butterfly. Apply a vacuum to the bottom port on actuator and you will see it pull the rod up part way. Apply a vacuum to top port and it will pull the rod up further. The diaphragm in the actuator is two stage.

Both 2.4s and the 3Ltr work in the same way I believe.

Nev

Nev spot on!

Just tested my actuator and vacuum to actuator B (Bottom) closes the butterfly about 80-90%.With vacuum at both actuators the butterfly closes completely.

Regards

Mark