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Discussion Starter · #1 ·
Hey Man, thanks again for all your help...As I was looking at this egr valve I am not seeing how it would "introduce" exhaust gas into the intake...I mean it is bolted onto the intake but thats it...There is no exhaust lines, or lines of any nature for that matter, except the coolant lines on either side of the tb that are even running to the egr...So how the heck does this valve let anything into the intake, when it is the only thing on the intake...Where the heck is the supply line for the exhaust gas on this thing, cause I don't see one, and I just had my upper intake off and I didn't have to disconnect anything from the egr except the electrical connection to get it off?????????....I'm confused...I understand "how" it is suppose to work, but if there is no line supplying exhaust running to my egr what does it matter if the diaphram opens or closes??????....Is my supply line missing or something or am I just "thinking" on the wrong track?

Jason
 

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The exhaust gas flows from the heads through internal passages in the intake all the way out to the EGR spacer that sits between the throttle body and the intake.

If you remove the spacer you will see them.
 

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Yup, If you've seen a 5.0 lower intake manifold off of the car, you'll notice the ports for each cylinder, four per side. Each side also has a port in the center, and that is the EGR passage. And the big ports on each end are for coolant. If you remove the EGR valve from the intake or spacer, you will see two holes. Those passages may very well be caked with crud. It would probably be better to remove the upper intake to clean them out, so you don't get any of that crap into the rest of your motor. I think EGR is the center port, where the upper meets the lower.

The electrical connection you mentioned, sounds like the Egr Valve Position sensor. It mounts on the EGR valve. You definitely need a vacuum line going to the EGR valve, and you definitely want the vacuum switched by the EVR, in order to keep EEC happy. And again, you should only be able to suck a little bit of air out of the vacuum port on the EGR valve, you should also be able to feel, hear, and see it actuating.
 

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Discussion Starter · #4 ·
Mean...now I see...Thanks guys for the explanation...Well, when I suk vaccum off the egr it doesn't move period...Like I said I get no resistance when I suk, just like it was attached to nothing...So I also tried your check of manual pushing the diaphram to see if it stumbles the engine at idle...It did, so what do I do now????...I know even if the evr is working to apply vaccum at the correct time, my egr diaphram would not be moving when it did so 2 questions arise...
1. what do I do, just replace the egr and then see what happens...would you go new or used?
2. Since my egr valve is obviously not working due to the fact it won't move when I suk it, why is my check engine light not on (it is working), are there any adverse effects I am/would be experiencing that you can think of?

Jason
 

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cfiiman said:
1. what do I do, just replace the egr and then see what happens...would you go new or used?
2. Since my egr valve is obviously not working due to the fact it won't move when I suk it, why is my check engine light not on (it is working), are there any adverse effects I am/would be experiencing that you can think of?
Jason
1. I'd absolutely seek out a used one to save some $$. Probably any Ford 5.0 from '86 or so, till '93, or so, should have what you need. You know how to test it... You'll know when you get one that works. But, if it ain't too pricey, a new one from Ford would be best. Parts stores have off-brands too, I think.
2. I guess it's not a big enough problem to trigger the light. but if you were to scan it for codes, I'd wager that you'd have a 33 Key On Engine Running, and a 34 stored in Continuous Memory from when you manually pushed the diaphram. You said the motor stumbled when you did that, and that's a good sign, because it means that your EGR passages are somewhat clear. The longer the EGR valve has been inoperative, the more crap will be in the passages. Some, or hopefully all of your car's detonation problems could be caused by the bad EGR valve.
 

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Discussion Starter · #6 ·
Hey thanks man for the reply...I'll look into the replacement...1 more question though...Why would an egr cause any detonation problem, especially mine b/c I know they cool the engine temp off some at part throttle applications, but don't engines detonate usually under the most load which would be wot applications???...The EGR is not even working then, which I always thought was when the most heat was present...I'm confused b/c if an egr works to prevent detonation at part throttle (which i'm still not sure what that means, or how a car would detonate at only part throttle) it seems like if someone had a working egr and they went from part throttle to wot as in a smooth roll on acceleration, that it would REALLY be prone to detonate b/c you would go from an egr cooling effect at part throttle, to NO cooling egr effect at the wot which is when it seems you would need it most...Is my thinking flawed????..Please explain...Thanks again...

Jason
 

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Hmmm, I didn't think about WOT. They will also detonate at part throttle though, you can have a load on/against the motor, at any RPM/throttle position.
I'd probably still restore the emissions functions. I just like knowing that everything is working on my car the way it was designed to, plus, I had to pass the sniffer... I'm not a tree hugger, at all. But EGR doesn't take any power away (that's what I've read), and it makes a huge difference as far as cleaning up the exhaust, and eliminating Hydro Carbons.

Have you considered the possibility that the harmonic balancer might be worn out? The rubber rots, causing the outer ring(with the timing marks) to shift, leading to incorrect timing readings. The typical occurence will lead to timing that is too advanced - if set with a timing light.
 
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