EGR Valve, Do I need it?

[gz32]

Do I realy need my egr valve. Mine sticks and makes my idle ruff.
Can i just clean it out so it dose not stick, then disconect the vacum line and plug it up. Will this hurt anything? dose the egr help/hurt performance?

Thanks for your hellp,
GZ32

90xj, 4x4, 4.0L

 

[Chief93XJ]

You need your EGR vale. It was designed to cool your comubustion chambers and to below 2500* F so you dont make NOx gas and pollute OUR atmosphere, also it prevents detonation from high combustion chambers. try to clean it off and work it back and forth, and if that doesnt work replace it. Also it sounds like its sticking in the open position so check that it is getting vacuum when it is supposed to and clean the little "bore" it fits into. Despite what people say, it doesnt hurt and it only helps prevent detonation and keeps our atmosphere cleaner.-Aaron

 

[Chief93XJ]

i meant to write "high combustion chamber temperature"^

 

[Matthew Currie]

Aaron is undoubtedly right when he says it serves a purpose and reduces pollution and combustion temperatures, so you should fix it. But I must mention that if you don't, the vehicle probably won't run any differently, and the knock sensor will control the detonation. So at least until you get it fixed, you can just crimp off its vacuum hose and go ahead. You shouldn't disarm the whole solenoid etc. because that also controls fuel tank purge venting.

Try cleaning the valve, but don't be surprised if it doesn't help. I think that the later (starting, I think, in mid-88) ones had a tendency to wear funny and hang up intermittently, not related to carbon buildup. Although I'm pretty sure it's irrelevant for the '90 in question, you should note also that the Haynes procedure for testing these does NOT apply to all versions. The one on my 87 had a back-pressure valve in the diaphragm, which allowed it to open only when there was sufficient exhaust back-pressure. This means that a good one will flunk the vacuum test.

 

[gz32]

Ok, thanks for you help. I will clean it out and hope that works. if not i guess i should get a new one. do you know how much the are?

 

[GreedyXJ]

The last one I got from the stealership was around $75.Make sure you ask for a gasket because it doesn't come with it and they probably won't ask you if you need one...

 

[Rags]

Gray area..........I never condone tampering with emissions stuff............you need it,fix it and stay legal if you drive it on the roads............software in the PCM and all that neat stuff is designed into the system so it can work as a whole and in harmony,EGR valves and the transducers cause some weird driveablity probs,if in doubt renew both............................give a hoot.............dont pollute............ ....and no.......I am not a tree hugger