SanDiegoPaul

When I put the motor in last month I didn't connect any of the TVS's except the EGR valve. I do indeed have a Thorley EFE valve on the end of the right side header collector ... and the smog pump is hooked up and turning. The fresh air tube goes to the headers but I have not completed the vacuum setup.

Since the smog pump has been running but has had no vac to the divertor valve attached to it, I'm woondering: is it pumping air into the headers all the time, or not at all? In other words, is the divertor valve OPEn with vac or does the vac close it? And how do I hook up the EFE?

I Have a new TVS in the manifold for the EFE valve. I think the lower line goes to the valve, and the upper one to vacuum. So is it MANIFOLD or is it PORTED vacuum? And where does the vacuum to the pump's divertor valve get hooked up??

:hat

Paul L

The diverter is closed under normal operating conditions. In other words the AIR pump is constantly delivering air to the exhaust manifolds in the area of the exhaust valves. The opening of the diverter valve is triggered by a sharp increase in manifold vacuum such as WOT. The valve diverts air (it opens)away from the exhaust manifold under this rich condition to prevent backfiring. Excess air is thus dumped through the pressure relief valve to the atmosphere. Here is the hose set-up.
http://temp.corvetteforum.net/c3/pau...ssions_002.jpg

SanDiegoPaul

. The opening of the diverter valve is triggered by a sharp increase in manifold vacuum such as WOT. The valve diverts air (it opens)away from the exhaust manifold under this rich condition to prevent backfiring. Excess air is thus dumped through the pressure relief valve to the atmosphere. Here is the hose set-up.


OK most of that refreshes my memory of the thing (I was actually working at Chevy when this thing was NEW so I should know this stuff :hat ) Also it explains the mild popping I get thru the exhaust on Deceleration - heck it's pumping fresh air all the time! I better hook it up.

But your statement about "sharp increase in manifold vacuum such as WOT" is definitely wrong: at WOT there is no or very LITTLE vacuum. :yesnod:

Thanks mucho though for the link to the vac schematics!! and GO BUCS!!!! :lol: :lol: :cheers: :cheers: :lol: :lol:


[Modified by SanDiegoPaul, 8:14 AM 1/25/2003]

Paul L

I stand corrected ;) . Enjoy the Super Bowl!

SanDiegoPaul

BTW the emission hose schematic you supplied (Thanks very much) is for Federal Emissions. Do ya have one for CA emissions?? :smash:

killain

My diverter valve is closed (Has Vacuum to it) only at start up, and it closes then as the water under the TVS gets hot the vacume is drained off and the valve opens. At least that is how my 79 L-48 works. It's line is the middle line on the TVS switch in the thermostat housing. Top line is vacuum.

SanDiegoPaul

Is it manifold vacuum or is it ported vacuum?

Paul L

I don't really see any difference. The TVS EFE and EGR switches are in the same configuration as the federal.
http://temp.corvetteforum.net/c3/pau...sions2_004.jpg

Paul L

It runs off the front of the carb. Thus it is manifold vacuum actuated.

SanDiegoPaul

Interesting! In that second diagram there is a dual snorkel air cleaner. Mine is single with an inlet that goes over the radiator for cool air.

Not that it changes anything ... The TAC's are run together but it's curious nonetheless.

Thanks!

Paul L

Please keep in mind that I am feeding you info from a 1979 L-82 dual snorkel intake system. I should have specified that earlier.







[Modified by paul79, 9:39 PM 1/25/2003]

SanDiegoPaul

Is taht an L-82 motor?