I need to order parts so I can put my new engine in on Sunday, but there is a part that was broken on my thermostat housing, and I don't know what the hell it was.

Please help me identify it!

According to my shop manual it is either a "EFE TVS Switch" or a "TR SPK TVS Switch" And according to Ecklers parts list, there was no "SPK Switch" for the '79.

The unidentifiable missing piece is the one on the left (obviously)


Still the one on the left.


Once again, the one on the left.
(I know, the one on the right is acutally broken too, but I know what that one is! |smile| It's the EGR Vac Control Switch.)



Thanks!

 

My first guess is the temp sending unit.

 

The one on the left is the EFE switch (heat riser)

 

It's the thermal vacuum switch (TVS). Check with the local Chev dealer tomorrow.

 

Pete,
Yes it activates this.

 

Paul79 hit it. Chevy, or NAPA have them. Take the old one for the exact thread pitch. Good luck on the engine install.

 

Alright, here's the thing...
in the attached copy of my shop manual, the two items on top of the thermostat housing that we are talking about I have colored blue & green.
According to the labels, the blue one is the "EFE TVS Switch" and the green one is the "TR SPK TVS Switch". And the one that I colored red, on the intake manifold, is the "EGR TVS Switch".

Thanks for your answers... but here's some more detail (and confusion) on this...

In Ecklers catalog, matching my part to their pictures, the blue one (EFE TVS Switch) is called the "EGR Vac Control Switch". The red one is called "EFE Vac Control" and the green on in question, since I don't have it, can't match it to a picture, nor do I see a listing in the catalog for a "Spark Control Switch" for a 79. :confused:

Can you guys offer any more help?

Thanks again!

 

by the way, anyone know what the meaning/difference is between?:
L48, L48 NB2 and L48 NA6





Thanks, again!! :cheers:

 

I think they are emissions codes, There was an L-48 which was sold throught out the bulk of the country, Eastern and midwest, One which was sold in the rockies, (hi altitude) model and the one made for the Califorina market. I have a 79 eastern L-48. It came with a EFE setup and Cat converter only. The Hi altitude model came with a different configuration and had a Air Pump. And the California model had all of the emissions equipment installed. Some parts like the "Thermatic Air cleaner' was a standard item as was the EFE valve.