(SOLVED) Dead cylinder at idle? Low temp on header collector

[92b]

The plate will separate the half’s on the intake. It’s impossible for the exhaust gas to travel to under the intake. The EGR valve has a vacuum operated valve that is open under idle to mid-ish throttle. It will close under a heavy throttle, approximately 3/4 of the way down. I don’t remember the exact reading I took on my EGR valve, but it was something like 9-11 inches.

When the WGR valve is open, it allows the exhaust gas to travel from one side of the intake to the other side. The plate blocks it off, period. Unless there is a bad gasket under it. Even then, it’s a very low amount.

I could be wrong but if I remember correctly the EGR should be closed at idle. I remember when I worked at the dealership diagnosing vehicles with a rough idle by using a screwdriver on the stem to pry open the egr valve and then letting it snap shut. Sometimes this would unstick a stuck valve or break up carbon in the seat of the valve causing it to seal back up.
If the plate is only sealed around the perimeter it could leak across the dividing wall. It doesn't take much for a vacuum leak especially if there is pressure on the exhaust side.

 

[macdrew77]

I could be wrong but if I remember correctly the EGR should be closed at idle. I remember when I worked at the dealership diagnosing vehicles with a rough idle by using a screwdriver on the stem to pry open the egr valve and then letting it snap shut. Sometimes this would unstick a stuck valve or break up carbon in the seat of the valve causing it to seal back up.
If the plate is only sealed around the perimeter it could leak across the dividing wall. It doesn't take much for a vacuum leak especially if there is pressure on the exhaust side.

You know what I probably only put copper rtv around the outside, but i can't remember.

 

[RustyRatRod]

I could be wrong but if I remember correctly the EGR should be closed at idle. I remember when I worked at the dealership diagnosing vehicles with a rough idle by using a screwdriver on the stem to pry open the egr valve and then letting it snap shut. Sometimes this would unstick a stuck valve or break up carbon in the seat of the valve causing it to seal back up.
If the plate is only sealed around the perimeter it could leak across the dividing wall. It doesn't take much for a vacuum leak especially if there is pressure on the exhaust side.

That's correct, since the proper vacuum source for the EGR is ported, so it would have no vacuum at idle and the valve would be closed.

 

[rumblefish360]

I'm sure you mean impossibly for exhaust to travel under the intake as in into the intake valley, right?

No, “Impossible.” But from that side of the manifold since that is the only focus I had on the idea. Not the passenger side.

Because exhaust DOES travel under the intake VIA the EGR passages and the exhaust cross over. Right?

Correct. Capping/sealing the area where the EGR valve is and now was stops the exhaust from going anywhere. At least that’s what I remember. I decided to go into the garage and see if I still had a EGR intake. I do not. I do not remember the exhaust gas being able to cross over if the valve was closed as well as after it’s removed and has a flat plate installed to prevent this.

I could be wrong but if I remember correctly the EGR should be closed at idle. I remember when I worked at the dealership diagnosing vehicles with a rough idle by using a screwdriver on the stem to pry open the egr valve and then letting it snap shut. Sometimes this would unstick a stuck valve or break up carbon in the seat of the valve causing it to seal back up.
If the plate is only sealed around the perimeter it could leak across the dividing wall. It doesn't take much for a vacuum leak especially if there is pressure on the exhaust side.

I’d say you would know better than me.

You know what I probably only put copper rtv around the outside, but i can't remember.

That could be a problem. The EGR gasket was that old very high temp material.

 

[RustyRatRod]

I have a couple of slant 6 EGR intakes, but they're a little different. lol

 

[rumblefish360]

I have a couple of slant 6 EGR intakes, but they're a little different. lol

I have no idea what they look like. Just 318-2’s & 360-2&4’s.