Blocking EGR Valve Question??

[casndaveRX2.8]

Looking to block the EGR valve on my 97 GQ 2.8 turbo. I think I have searched through all the posts on here regarding Blocking EGR valves on the 2.8 turbo and I cant see any refrence to the pipe off the exhaust manifold that brings the exhaust gasses to the EGR valve.

Does this stay hooked up to the EGR valve when blocked or do you remove it and put some sort of plug in the exhaust manifold?

[Godders]

Just leave the pipe connected you are only blocking the valve.

You should notice a reasonable differance at first untill you get used to it, then it happens all over again.

Why doesn't my car go any faster??

[hhl]

There is not a lot to be gained in the 2.8. In the 2.8 the EGR valve is only open at idle, so there will be NO power increase at all as it shuts as soon as soon as you accelarate.

[DansGQ]

There is not a lot to be gained in the 2.8. In the 2.8 the EGR valve is only open at idle, so there will be NO power increase at all as it shuts as soon as soon as you accelarate.


can anyone verifiy this

cheers dan

[tweak'e]

just going through the manual at the moment. i'm not 100% sure it s the same motor but it appears hhl is correct.
thats actually kind of odd as most motors have egr OFF at idle.
only thing to check is that the egr and butterfly are normally open or normally closed.

also it pays to check the operation with engine in gear. the testing in the manual i think would be with gearbox in neutral. i think there is a mention of gearbox switch, so its possible its operation is different than whats shown in the manual.

[DansGQ]

it didnt realy explain to me what i wanted to no when o read the manual

[tweak'e]

so far in the manual i found the test procedure. it doesn't say that egr is only used at idle. i havn't found what other conditions are a factor.

easiest way is to simply test it. fit a light or vac guages to the solnoids that run the egr and butterfly and go for a drive (motor must be warmed up tho).

[geordie4x4]

Originally Posted by DansGQ

There is not a lot to be gained in the 2.8. In the 2.8 the EGR valve is only open at idle, so there will be NO power increase at all as it shuts as soon as soon as you accelarate.


can anyone verifiy this

cheers dan

Like tweak'e said, test it with a gauge or light.
If it is anything like the 2.7 Terrano (mine was a 1992) I tested the vaccum with a gauge to see when it opened and closed. Yes it was open at idle (with the auto gearbox in N, P or D but seemed to shut in R). It closed as you accelerate. But it then opened again at cruising speed and when you back off slightly.

I closed it off because I could not use an exhaust jack without the motor stalling when the back pressure of the jack caused excess exhust into the motor.

[HS9090]

Originally Posted by hhl

There is not a lot to be gained in the 2.8. In the 2.8 the EGR valve is only open at idle, so there will be NO power increase at all as it shuts as soon as soon as you accelarate.

EGR is an emission control device. It supplies inert gas (exhaust) to the intake to take the place of some of the oxygen so the whole idea is to reduce power with the objective of reducing peak combustion temperatures where Oxides of Nitorgen (Nox) not Nitrous Oxide (Nos) are formed, thus reducing Nox emissions.
If it is only open at idle on the 2.8 I don't see how it can do its job.
The bad side effect of EGR, apart from power loss, is the carbon build up in the intake manifold, intake ports and on the intake valves.
Nox emissions can be more effectively reduced by water injection which also increases power and cleans up the carbon deposits etc.
Best thing to do for a 2.8 would be to replace the EGR with water injection.
That's what I intend to do to mine.

[dacolprt]

New here fella's, the egr valve requires vacume to open, so I just disconnected (blocked) the signal (vacume) hose to the valve. So the valve dosnt open sending exhaust gases to intake. Correct me if Im wrong.

[tweak'e]

yeah you can do that but there is a possiblity that the valve can be jammed opened which is why blocking the valve off is much better.