Another EGR valve question

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Oct 11, 2006
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Location
Las Vegas, Nevada
My 60 runs like crap with the EGR valve connected to the modulator and have been running it forever disconnected, would a bad EGR valve still connected to the intake decrease the engine performance? ( i.e. rough idle and power loss)? Someone mentioned to me that the valve can actualy leek allowing exhaust gases to enter the manifold at any given time. Can anyone please verify this?
 
the EGR valve can become stuck open. pull it off and clean it out, spray a little carb cleaner or pb blaster on the valve itself and push it in and out with a screw driver. Don't spray anything into the vacuum connection on top of the EGR valve. This usually gets me going again for another year ;)
 
The modulator applies vacuum to the egr valve to open it. There is a spring on the egr valve to close it when no vacuum is applied. However, depending upon the condition, the valve seal may be corroded and/or the valve may be stuck in a partially open position. You can take the valve off the engine and see if the valve stem moves freely or if the seat seems to be corroded.
 
Just pryed the computer away from my girlfreind- a little late here but thanks for the input- I'll yank off the valve this weekend and see what's going on inside.
 
What about the EGR modulator? Is there a way to objectively measure the air flow through it? I took mine apart and cleaned the filter in it and checked the air flow as per the FSM. It works, but took more pressure and had less air flow than I expected when I was blowing through the different ports.

I definitely don't want to replace that part just to see if it's working$$.
 
EGR Vacuum modulator test

What about the EGR modulator? Is there a way to objectively measure the air flow through it? I took mine apart and cleaned the filter in it and checked the air flow as per the FSM. It works, but took more pressure and had less air flow than I expected when I was blowing through the different ports.

I definitely don't want to replace that part just to see if it's working$$.

Hank, This is EXACTLY where I'm at right now! Following the test procedure page 3-17 in the FSM: "Blow air into port Q. Check that the air passes through to the air filter side freely". I get air flow, but wouldn't necessarily characterize it as "freely". Freely is kind of a squishy word. Anyone know - should there be virtualy no resistance to air flow? Would some resistance give you EGR type symptoms (bucking/stumbling under throttle)?

Butt
 
Mine does not flow freely. It flows, but with sone resistance. The filter was clean, but I degreased it and blew it out anyways.

All I know is if I apply vaccuum to the EGR while idling, the engine nearly stalls, indicating the EGR is working properly. BUT- when the EGR is connected to the modulator, it bucks, surges, and generally runs like an old Craftsman riding mower.

When it is disconnected and capped off "egr bypass method", it runs like a new Craftsman riding mower.
 
You're welcome. I don't envy you on the smog test. I don't have to test in my county...yet, but I figure if I'm going to have all that crap under the hood, it might as well work. I'd rip it out, but as soon as I do, I'll decide to sell this fine piece of machinery or something.

I ticked me off when I saw an 83 FJ60 that I looked at 2 years ago for sale again and the seller was braggin about how easily his passed smog- and it's exempt everywhere in Texas this year! (24 years)
 
Here's a picture of how I replaced the EGR modulator filter- I used cotton makeup removal pads from my wife- just cut them to fit. After looking again at the modulator filter, the dense part of it was not letting much air through. I think this was "starving" the EGR valve or forcing more exhaust gas to recirculate instead of taking in fresh air.

After doing this and a few other things working through the emissions manual, she is running better than she ever has with all the smog equipment intact. Very minimal bucking and surging- and I'm not through the manual yet!

IMG_0617.jpg
 
i'm in a similar situation but am trying to get the damn egr off. i can't for the life of me break loose the bottom j-pipe nut. i've tried to get a wrench on the top nut near the egr but it won't budge either. i've figured out it needs about a 27mm wrench so i thought about buying a box ended one and cutting a slot sort of like a brake line wrench. hopefully getting more torque on the nut to break it loose.
 
thanks Hank - I had my modulator open yesterday and was thinking how to change the filter - my EGR valve stalls the engine when vacuum is applied as it should. but does not hold the vacuum. Tech says the diaphragm is bad and I need a new EGR. Does that sound right?
 
The schematics for the EGR imply that the diphragm is not vented and it should hold vacuum. However the test procedure for the EGR in the emissions manual only has the engine stall test. If applying vacuum to the EGR valve stalls the engine (or causes it to idle rough), then the EGR valve is considered to be working properly.

Are you having problems passing smog? Why is a tech mucking around with your engine?
 

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