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2jzgte Exhaust gas control valve


fastphil666

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How hard is the egcv actuator rod to move by hand? 

Have an intermittent issue, if i run my auto in manual mode, in second about 35mph and stamp on it, i sometimes dont get 2nd turbo. Also had it in auto when its changed down an no boost. Noticed an odd noise, like air escaping as boost builds (like a blown ic pipe) 

 

Ive checked all vsv's and replaced all vacuum pipes apart from the 2 to the pressure tank (fat hands) all ok. 

 

It did it on a run last week, popped the bonnet and gave it a rev, you could see the actuator rod move, but seemed to be notchy movements when returning to normal position?

 

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Phil, you've done the two accordion type link pipes too? 

On the actuator rod, are you talking the one back from the alternator, pre the 1st cat?

If you can squeeze your hand down there, there is a sort of adjustable return stop. I think the flap inside can get a bit coked up/sticky and when it's in it's returned position it gets wedged a tad. This flap is opened right up for the non sequential operation I believe and so on an old car I adjusted this stop so it didn't return as far (you risk it being a tiny fraction open) and I'm sure it improved things.   

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On 11/26/2020 at 3:16 PM, Scooter said:

Phil, you've done the two accordion type link pipes too? 

On the actuator rod, are you talking the one back from the alternator, pre the 1st cat?

If you can squeeze your hand down there, there is a sort of adjustable return stop. I think the flap inside can get a bit coked up/sticky and when it's in it's returned position it gets wedged a tad. This flap is opened right up for the non sequential operation I believe and so on an old car I adjusted this stop so it didn't return as far (you risk it being a tiny fraction open) and I'm sure it improved things.   

The accordion pipes, do you mean the pipes on top that join the 2 turbo's?         One is a greddy silicone hose, the other looks non-oem too. 

I will have a good look today, i have an 11 month old so spare time is tight. See what i can see. 

 

Thanks for your help guys, i'll check if theres anything unterward before i adjust a thing. 

20200314_143948.jpg

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On 12/2/2020 at 1:57 PM, Chris Wilson said:

Very hard, it has a robust spring inside it. You need a Mityvac pump and gauge to check it properly. they can and do seize up. The arm the rod goes to on the ceramic flap can break, or partially break, away. It's also adjustable... But don't fiddle with that just yet!!

Hi chris, if i find it is stiff to move or getting wedged in place, can i remove the exhaust and clean it up? Also can it be greased in any way so it doesnt do it again? 

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You'd have to remove the casting it is inside, (exhaust mid section or second CAT off, first cat or decat pipe off, then difficult to reach nuts to drop the casting with the flap in from the turbos and you may need to remove remove the O2 sensor to clear the steering column shaft. I made a special spanner to remove the awkward nut.  Risk of stud breaking, nuts seizing, personal injury, bad language, unexpected expenses....  :) I can't remember if the thing uses pressure or vacuum to open, but to test it you need to apply one or the other to the capsule. If 9PSI above atmospheric won't open it, or a vacuum of 22 inches Hg,  it's stuck, or the actuator is knackered. Don't drop the flap part that can come out of the casting, it's ceramic, will shatter and is VERY VERY expensive if you need a new one. Tapping or prising at the thing will do terrible things to it as well... It's a sophisticated bit of kit.

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Thanks again for the replies, had a good look again, checked all vsv's and they have no issues, continuity and flow and switched flow all good. Checked the boost pipe that can collapse inside, thats fine. 

 

I used a bicycle pump on the actuators, egbv and egcv both move with very little pressure applied.

 

Whats the purpose of the pressure tank? I'll have to check hoses for it. 

 

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17 hours ago, fastphil666 said:

Thanks again for the replies, had a good look again, checked all vsv's and they have no issues, continuity and flow and switched flow all good. Checked the boost pipe that can collapse inside, thats fine. 

 

I used a bicycle pump on the actuators, egbv and egcv both move with very little pressure applied.

 

Whats the purpose of the pressure tank? I'll have to check hoses for it. 

 

It should hold boost PRESSURE for operation of parts of the turbo control system during periods of engine operation under conditions of intake vacuum.

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On 12/7/2020 at 9:43 AM, Chris Wilson said:

It should hold boost PRESSURE for operation of parts of the turbo control system during periods of engine operation under conditions of intake vacuum.

So in the situation i describe, drop down to a lower gear then ask it to build boost from nothing may be the issue?

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18 hours ago, Chris Wilson said:

Round the back of the head, are two steel pipes, going to rubber and back to steel, they feed the pressure vessel, one may be off, loose or split. With the engine in they are a nightmare to get at, you have to work by feel. Get some bandages ready for your grazed hands and wrists. have fun... :)

I have had a feel of these before and will change them as a matter of cause, like you say though theyre tough to get at and yes i cut my hands to bits. Will have another go or get the wife/babies hands in there 😉

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