Finally narrowed it down... (but still need help)

[supkylesup]

Alright guys ive had this ongoing problem for about a month now and it's driving me and my wallet crazy.
So the problem is my car violently surges (like it's lacking fuel or air) at the most random times.
The problem has not yet once been consistent in the times it has happened.
So here is a list of things I've replaced:
Egr valve, plugs, wires, distributor cap, rotor, coil, carb professionally rebuilt, fuel filters, and egr vaccum solenoid.
Now here is what I've discovered after many many attempts and different things.
My check engine light comes on when the engine reaches normal operator temp.
The code is a code 53 (egr) which I've already replaced.
So 3 days ago I unplugged the small vaccum line that runs from the egr to a T which leads to the vaccum solenoid.
Now after removing this line my car has been running perfect for the past 3 days.
So I figured today I'd replace the egr vaccum solenoid.
Replaced it and plugged the vacuum line in and almost instantly the surging started!!!!

So I've narrowed it down to the egr system being at fault.
Now what the hell could be the problem?????
In tired or replacing stuff and trying stuff.
Any input on this would be awsome.
And thanks in advance guys
The engine is a stock 3.8l v6

 

[supkylesup]

Re: Finally narrowed it down...

Anyone got a clue?

 

[kornball426]

Well I was going to say... Just plug up your EGR valve with JB Weld or something and you'll never have an EGR problem ever again... But seeing as it's a brand new EGR valve that seems a little wasteful. You could just disconnect the vacuum line and cap it off...

Although these vacuum EGR's I've never bought one, how much do they cost? If it's cheap I'd just plug it up, it doesn't do anything anyway... It's just emissions BS. The electronic ones can cost like 150 bucks or more, if it was pricey I'd try getting them to give you another new one and see if that helps, and get a gasket with a carbon screen and see if it changes anything. My EGR valve kept getting clogged up and stuck one time, I got tired of taking it off to clean it out and having to replace the gasket... Until I got a gasket with a carbon screen, once I installed that I never had a problem with it ever again.

 

[Pbngem]

Can you post a pic of the egr valve & solenoid? Also, what year is your car?

 

[supkylesup]

Well here is the thing I know what to do to make it right run but after a month of it doing this I want to know why it was doing it. What about my egr system could cause something like violent surging.
But I'll get a picture up soon

 

[Pbngem]

I'm guessing that too much EGR was being applied. The effects would be similar to disconnecting a large vacuum hose. EGR is typically applied during part throttle/cruise conditions, but not at idle. I'm thinking that the EGR solenoid is a PWM type solenoid which gives the ECM control over the EGR being applied.

 

[1evilregal]

is the egr opening when you hooked the vacuum up? if so, it shouldn't be opening at idle.... make sure the vacuum lines are hooked up in the right places.