What is PEVR and what does it do?

[Graeme]

The Haynes book is little help, but it's all I have at the moment.

What's the Power Enrichment Vacuum Regulator (PEVR) and what does it do? Is it related to preventing a lean condition when the throttles are closed under a boost condition?

Thanks,

 

[Graeme]

My apologies, I should have done a search first. Still, anyone who wants to chime in is welcome.

There must be a specific part number for the turbo Q-jet that's vented to the PEVR? I don't have a Q-jet to look at, it was missing.

 

[b4black]

ROCHESTER CARBURETOR NUMBERS - All 1978-83 Turbo V6 engines originally came with a Rochester Carburetor. In 1981, (1980 in California) Buick began to use computer controlled carburetors. Due to the complicated emissions/vacuum system of these cars, I believe it is important to have the correct carburetor. Follow this link to a table with the production numbers and models used; TURBO V6 CARBURETORS

"ROCHESTER CARBURETORS" By Doug Roe- I highly Recommend this book. It explains the operation, repair, tuning and performance modifications of the Quadrajet and other Rochester carbs. Covers electronic and non-electronic carburetors. Published by HP Books, copyright 1981.

CARBURETOR POWER SYSTEM - Non-electronic carburetors use a Power valve to enrich the mixture during acceleration or high speed operation (to prevent detonation). This system is modified for Turbo applications. (One reason a Turbo carb is different than other carbs.) The power system works off manifold vacuum. Low or no-vacuum situations open the release (open) the power valve. Most carbs get this vacuum signal from a port with the carb. In a draw-through turbo set up, the carburetor is separated from the intake by the turbocharger. Releasing the throttle when the engine is under boost will produce vacuum within the plenum. However the intake will still be supercharged. The plenum vacuum will close the power valve and lean out the mixture and cause detonation. To correct this, the power system needs to be connected to the intake manifold down stream of the turbo. It also needs to be protected from boost pressure. (When the intake is pressurized, the power valve should receive no vacuum and no pressure). This is accomplished with a Power Enrichment Control Valve (PECV) or Turbocharger Vacuum Bleed Valve (TVBV).

 

[b4black]

Find carb numbers here:
http://www.flash.net/~rjgeorge/carbs.htm

 

[Graeme]

Thanks, Rich.

So, for my cobbled together Ford six system it looks as though I should find a rebuilt 78-79 turbo Q-jet and a PEVR to screw into the intake manifold.

I'll check the carb numbers against the catalog at the local parts house. It did show a turbo Q-jet.

Thanks again for the info.