Tomco EGR

[b4black]

Last fall, I installed a Tomco EGR valve. I like this valve because the backpressure transducer is external. The exhaust back pressure and the exact vacuum to the valve can be monitored.

I hooked up a vacuum gauge to see when the valve is open. Never. The valve is already dead. (I think it has a lifetime warrenty.)

In the meantime, I hooked the gauge up to the EGR solenoid to see when it should open.
At idle - off
very light throttle to heavy throttle - on
WOT - off again

The transducer blocks vacuum to the valve at zero backpressure. With a turbo, there almost always is backpressure. I might try running just the valve and no trandsucer. Keep it simple.

 

[Freddie's Buick]

Rich,

On some of these EGR valves for our cars applying direct vacuum does not nessacerily open the valve.

It has to rev at 3000 RPM. This is for the negative backpressure type EGR for cars with relatively low backpressure.

Perhaps yours is one.

 

[b4black]

With the external tranducer, the Tomco valve itself responds directly to pressure. By T'ing in-line between the valve and tranducer (not possible on the OEM design), I should be able to see when the valve is trying to open.

 

[b4black]

Here a picture I took before I installed it:
http://home.flash.net/~rjgeorge/images/egr.jpg

The EGR valve gets in the way of removing the knock sensor, so when I replace the EGR I'm gonna do the knock sensor as well (just to be 100% sure it's working right).